WO2025181213A1

WO2025181213A1 - Aerosol-generating device with dual heating architecture

Info

Publication number: WO2025181213A1
Application number: PCT/EP2025/055307
Authority: WO
Inventors: Larry Sacha Baudet; Johannes Petrus Maria Pijnenburg; Stefano RIARIO
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2024-02-28
Filing date: 2025-02-27
Publication date: 2025-09-04
Anticipated expiration: 2026-08-28

Abstract

An aerosol-generating device (300) for generating aerosol from an aerosol-generating article (1002) comprises a first heating arrangement with an inductor element (324) and a second heating arrangement with an external resistive heating element (144) configured for heating the aerosol-generating article when in use. The first heating arrangement and the second heating arrangement are electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively. A power supply system is configured to supply power to the first heating arrangement and the second heating arrangement. A control system is configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively. The aerosol-generating article (1002) is received in a chamber (16) of the aerosol-generating device.

Description

AEROSOL-GENERATING DEVICE WITH DUAL HEATING ARCHITECTURE

The present disclosure relates to an aerosol-generating device, an aerosol-generating system, and an associated method of controlling the aerosol-generating system to generate an aerosol.

It is known to evolve an aerosol from an aerosol-forming substrate of an aerosolgenerating article by the application of heat to the substrate of the article, without burning or combustion of the substrate. In the field of aerosol-generation of an inhalable aerosol containing nicotine for human inhalation, the aerosol-generating article may be cylindrical, like a cigarette, and the aerosol-forming substrate may comprise tobacco material. It is known to use an aerosol-generating device to apply heat to such an aerosol-generating article to heat the aerosol-forming substrate of the article. In some examples, the aerosol-generating article is received within a chamber of the aerosol-generating device. It is known to use a heating arrangement that is external to the aerosol-generating article, or use a heating arrangement located within the interior of the aerosol-forming substrate. It is also known that the article may have a solid aerosol-forming substrate, or that the article is in the form of a cartridge or container for storing a liquid aerosol-forming substrate.

It is desirable to heat all of the aerosol-forming substrate so that it is possible to extract aerosol-forming material from the entire substrate. This maximises the amount of desirable aerosol that can be generated. Also, it is desirable to perform a heating-up operation as fast as possible, to shorten the start-up period before the human inhalation. To try to achieve this, it is also known to use more than one heating arrangement to heat different portions of the aerosol-forming substrate.

However, it is also desirable that the aerosol-generating device be small enough to be easily portable. This puts a limitation on the size of the power source in the device. The operation of more than one heating arrangement to heat the aerosol-forming substrate may result in excessive current being drawn from the limited power source of the aerosolgenerating device. This may result in a reduced power source lifespan, which is detrimental to use of the aerosol-generating device. This may also result in the power source overheating, which may present a danger to the integrity of the power source. This is particularly the case when more than one heating arrangement is drawing a current from the power supply at any one time.

It is therefore desired to provide an aerosol-generating device that controls the operation of the more than one heating arrangement to optimize aerosol generated from an aerosolgenerating article, whilst mitigating stress on the power source and preserving a power source lifespan.

According to the present disclosure, there is provided an aerosol-generating device for generating aerosol from an aerosol-generating article. The aerosol-generating device may comprise a first heating arrangement. The aerosol-generating device may comprise a second heating arrangement. The first heating arrangement may be configured for heating the aerosol-generating article when in use. The second heating arrangement may be configured for heating the aerosol-generating article when in use. The first heating arrangement and the second heating arrangement may be electrically connected to a first switching circuitry arrangement and a second switching circuitry arrangement respectively. The aerosolgenerating device may comprise a power supply system configured to supply power to the first heating arrangement and the second heating arrangement. The aerosol-generating device may comprise a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively.

According to a first aspect of the present disclosure, there is provided an aerosolgenerating device for generating aerosol from an aerosol-generating article, the aerosolgenerating device comprising a first heating arrangement and a second heating arrangement configured for heating the aerosol-generating article when in use, the first heating arrangement and the second heating arrangement electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively; a power supply system configured to supply power to the first heating arrangement and the second heating arrangement, and a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively.

Advantageously, a first switching circuitry arrangement and a separate second switching circuitry arrangement allows for the control system to exercise separate control of the operation of, and power supply to, the first heating arrangement and the second heating arrangement. Such a configuration also facilitates the ability for the control system to ensure that power is not supplied from the power supply system to both the first heating arrangement and the second heating arrangement concurrently. Therefore, this configuration may reduce the risk that the power supply system is overloaded as too much current is drawn from the power supply system. This in turn may result in a longer lifespan of the power supply system, or reduce the risk of the power supply system overheating.

The power supply system may include a first power supply. The first power supply may be configured to supply power to the first heating arrangement. The first power supply may be configured to supply power to the second heating arrangement.

The control system may include a first control unit. The first control unit may be configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement. The first control unit may be configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement. The first control unit may comprise a controller or a processor. The first control unit may comprise a microcontroller or a microprocessor. The first control unit may comprise electronic storage for storing data. The electronic storage may be configured to store heating profiles or target temperatures for the first heating arrangement. The electronic storage may be configured to store heating profiles or target temperatures for the second heating arrangement.

Advantageously, only a single power supply and a single control unit is therefore required to power and control the operation of two heating arrangements.

The control system may be configured to control the power supplied to the first heating arrangement and the second heating arrangement dependent on a first feedback signal and a second feedback signal respectively.

The first switching circuitry arrangement may be configured to provide the first feedback signal to the first control unit. The second switching circuitry arrangement may be configured to provide the second feedback signal to the first control unit.

The first and second feedback signals may be electrical feedback signals. For example, the first and second feedback signals may comprise one or more of a voltage, a current, or a conductance. The first feedback signal may be dependent on a temperature of the first heating arrangement. The second feedback signal may be dependent on a temperature of the second heating arrangement.

The first feedback signal may be dependent on a temperature of a susceptor coupled to the first heating arrangement. Alternatively, the second feedback signal may be dependent on a temperature of a susceptor coupled to the second heating arrangement.

The first control unit may be configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal. The first control unit may therefore be configured to control the amount of heating by the first heating arrangement. The first control unit may be configured to control the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal. The first control unit may therefore be configured to control the amount of heating by the second heating arrangement. Advantageously, the control system may therefore accurately control the amount of heating by the first heating arrangement and by the second heating arrangement, and in use such control may allow for better aerosol characteristics from an aerosol-forming substrate to be achieved, and reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours

The first control unit may be configured to control the temperature of the first heating arrangement to follow a first heating profile. The first control unit may be configured to control the temperature of the second heating arrangement to follow a second heating profile. The first control unit may be configured to control the first heating arrangement to maintain the temperature of the first heating arrangement at a first target temperature. The first control unit may be configured to control the second heating arrangement to maintain the temperature of the second heating arrangement at a second target temperature. Advantageously, predetermined heating profiles and/or target temperatures for one or both of the first and second heating arrangements may be loaded onto memory in the first control unit. The predetermined heating profiles and/or target temperatures may be result in particularly desirable aerosol-generation characteristics when implemented during use.

The first control unit may be configured to control the first heating arrangement such that the temperature of a susceptor element coupled to the first heating arrangement follows a first heating profile. Alternatively, the first control unit may be configured to control the second heating arrangement such that the temperature of a susceptor element coupled to the second heating arrangement follows a second heating profile. The first control unit may be configured to control the first heating arrangement to maintain the temperature of a susceptor element coupled to the first heating arrangement at a first target temperature. Alternatively, the first control unit may be configured to control the second heating arrangement to maintain the temperature of a susceptor element coupled to the second heating arrangement at a second target temperature. Advantageously, predetermined heating profiles and/or target temperatures for a susceptor element coupled to one of the first or second heating arrangements may be loaded onto memory in the first control unit. The predetermined heating profiles and/or target temperatures may be result in particularly desirable aerosolgeneration characteristics when implemented during use.

The first power supply may be configured to supply power to the first control unit. The first control unit may require power to operate, as the first control unit may be a microprocessor. Advantageously, by the first power supply supplying power to the first control unit, a further dedicated power supply for the first control unit is not required, simplifying the design of the device.

The control system may include a second control unit configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement. The second control unit may comprise a controller or a processor. The second control unit may comprise a microcontroller or a microprocessor. The second control unit may comprise electronic storage for storing data. The electronic storage may be configured to store heating profiles or target temperatures for the first heating arrangement. The electronic storage may be configured to store heating profiles or target temperatures for the second heating arrangement. Advantageously, only a single power supply is therefore required to power the operation of two heating arrangements.

The second switching circuitry arrangement may be configured to provide the second feedback signal to the second control unit.

The second control unit may be configured to control the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal. The second control unit may therefore be configured to control the amount of heating by the second heating arrangement.

The second control unit may be configured to control the temperature of the second heating arrangement to follow a second heating profile. The second control unit may be configured to control the second heating arrangement to maintain the temperature of the second heating arrangement at a second target temperature. Advantageously, predetermined heating profiles and/or target temperatures for one or both of the first and second heating arrangements may be loaded onto memory in one or both of the first or second control unit. The predetermined heating profiles and/or target temperatures may be result in particularly desirable aerosol-generation characteristics when implemented during use.

The first control unit may be configured to control the first heating arrangement such that the temperature of a susceptor element coupled to the first heating arrangement follows a first heating profile. Alternatively, the second control unit may be configured to control the second heating arrangement such that the temperature of a susceptor element coupled to the second heating arrangement follows a second heating profile. The first control unit may be configured to control the first heating arrangement to maintain the temperature of a susceptor element coupled to the first heating arrangement at a first target temperature. Alternatively, the second control unit may be configured to control the second heating arrangement to maintain the temperature of a susceptor element coupled to the second heating arrangement at a second target temperature. Advantageously, predetermined heating profiles and/or target temperatures for a susceptor element coupled to one of the first or second heating arrangements may be loaded onto memory in the corresponding first or second control unit. The predetermined heating profiles and/or target temperatures may be result in particularly desirable aerosol-generation characteristics when implemented during use.

The first control unit may be configured to provide a control signal to the second control unit. The second control unit may be configured to control the supply of power from the first power supply to the second heating arrangement dependent on the control signal.

The control signal may be an electrical control signal. For example, the control signal may comprise one or more of a voltage, a current, or a conductance. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. Such an arrangement may synchronise the operation of the first and second heating arrangements without the requirement of the first control unit and the second control unit to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the second control unit need not comprise any timing means. This simplifies the manufacture of the second control unit, and therefore of any such aerosol-generating device comprising said control system.

The control signal may be provided to the second control unit only when power is supplied from the first power supply to the first heating arrangement. The control signal may be provided to the second control unit only when power is not supplied from the first power supply to the first heating arrangement. The second control unit may be configured to control the second switching circuitry arrangement to prevent the supply of power from the first power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement. Advantageously, the control circuitry may therefore avoid both the first and second heating arrangements being powered simultaneously.

The second control unit may be configured to provide a control signal to the first control unit. The first control unit may be configured to control the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

The control signal may be an electrical control signal. For example, the control signal may comprise one or more of a voltage, a current, or a conductance. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. Such an arrangement may synchronise the operation of the first and second heating arrangements without the requirement of the first control unit and the second control unit to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the first control unit need not comprise any timing means. This simplifies the manufacture of the first control unit, and therefore of any such aerosol-generating device comprising said control system.

The control signal may be provided to the first control unit only when power is supplied from the first power supply to the second heating arrangement. The control signal may be provided to the first control unit only when power is not supplied from the first power supply to the second heating arrangement. The first control unit may be configured to control the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the first power supply to the second heating arrangement. Advantageously, the control circuitry may therefore avoid both the first and second heating arrangements being powered simultaneously.

The first power supply may be configured to supply power to the first control unit and the second control unit. Advantageously, by the first power supply supplying power to the first and second control units, a further dedicated power supply for the first and second control units is not required, simplifying the design of the device.

The power supply system may consist of the first power supply. The first power supply may include only one DC power supply. The first power supply may include only one battery cell. The first power supply may consist of one battery cell. The first power supply may be a rechargeable power supply, such as a lithium-ion battery. The first power supply may include a 18650 cell, a 14500 cell, or a 14650 cell, or other type of single-cell battery.

The power supply system may comprise a first power supply configured to supply power to the first heating arrangement and a second power supply configured to supply power to the second heating arrangement.

Advantageously, by including dedicated power supplies for both the first heating arrangement and the second heating arrangement, the risk that the first heating arrangement and the second heating arrangement draw excessive current from the power supply system, for example when both heating arrangements are powered for energy-intensive heating, is mitigated. Such an arrangement also allows for both the first heating arrangement and the second heating arrangement to be powered concurrently for heating without drawing excessive current from the power supply system. Also advantageously, only a single control unit may therefore be required to control the operation of two heating arrangements.

The first control unit may be configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement. The first control unit may be configured to control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement.

The first control unit may be configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal. The first control unit may be configured to control the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

One or both of the first power supply and the second power supply may be configured to supply power to the first control unit.

The second control unit may be configured to control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement. Advantageously, by separating the first and second power supply, first and second control unit, first and second switching arrangement, and first and second heating arrangement, the aerosol-generating device may be manufactured in a more modular fashion. For example, a first heating arrangement with a first switching arrangement, a first control unit and a first power supply may be manufactured separately to the rest of the components of the aerosol-generating device. The second control unit may be configured to control the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

The second control unit may be configured to control the supply of power from the second power supply to the second heating arrangement dependent on the control signal. The second control unit may be configured to control the second switching circuitry arrangement to prevent the supply of power from the second power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement.

The second control unit may be configured to control the second switching circuitry arrangement to prevent the supply of power from the second power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. As above, this means that the second control unit need not comprise any timing means which simplifies the manufacture of the second control unit, and therefore of any such aerosol-generating device comprising said control system. Furthermore, such an arrangement allows for synchronization of power supplied to the first and second heating arrangements, and allows for the system to avoid power being supplied from the first power supply to the first heating arrangement and from the second power supply to the second heating arrangement concurrently.

The first control unit may be configured to control the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the second power supply to the second heating arrangement.

The control signal may be provided to the first control unit only when power is supplied from the second power supply to the second heating arrangement. The control signal may be provided to the first control unit only when power is not supplied from the second power supply to the second heating arrangement. The first control unit may be configured to control the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the second power supply to the second heating arrangement. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. As above, this means that the first control unit need not comprise any timing means which simplifies the manufacture of the second control unit, and therefore of any such aerosol-generating device comprising said control system. Furthermore, such an arrangement allows for synchronization of power supplied to the first and second heating arrangements, and allows for the system to avoid power being supplied from the first power supply to the first heating arrangement and from the second power supply to the second heating arrangement concurrently. The first power supply may be configured to supply power to the first control unit. The second power supply may be configured to supply power to the second control unit.

The second power supply may be configured to supply power to the first control unit. The first power supply may be configured to supply power to the second control unit.

The first power supply may not be configured to supply power to the second heating arrangement. The second power supply may not be configured to supply power to the first heating arrangement. The first and second heating arrangements may therefore have dedicated power supplies. The first and second power supply specifications may therefore be tailored to the power requirements of the heating power of the corresponding heating arrangement.

The power supply system may consist of the first power supply and the second power supply. Both the first power supply and the second power supply may include only one DC power supply each. Both the first power supply and the second power supply may include only one battery cell each. Both the first power supply and the second power supply may consist of one battery cell each.

Each of the first power supply and the second power supply may be a rechargeable power supply, such as a lithium-ion battery. Each of the first power supply and the second power supply may include a 18650 cell, a 14500 cell, or a 14650 cell, or another type of single-cell battery. Advantageously, the first power supply and the second power supply will therefore not require frequent replacement.

The first power supply and the second power supply are packaged together in a single power supply unit, for example by using exactly two battery cells. Advantageously, the single power supply unit may be removed and replaced as a single unit. The single power supply unit may be rechargeable using a singular recharging connection. Advantageously, a user may therefore not require two separate electrical connectors to recharge the single power supply unit.

The first heating arrangement may be a first heater. The second heating arrangement may be a second heater. The first heater may be separate to the second heater. In this embodiment, the first heater and the second heater may advantageously be configured to heat different zones within an aerosol-forming substrate of an aerosol-generating article coupled to the device. This may advantageously result in more desirable characteristics of the aerosol produced. It is also possible that a first heater is used for pre-heating or heating incoming air upstream of the cavity that can removably hold the aerosol-forming article with the substrate, and that the second heater is arranged to heat the aerosol-forming article when located inside the cavity.

Alternatively, a singular heater may comprise the first heating arrangement and the second heating arrangement. In this embodiment, the first heating arrangement may comprise the singular heater and electrical wiring from the first switching arrangement to the singular heater. The second heating arrangement may comprise the singular heater and electrical wiring from the second switching arrangement to the singular heater. The singular heater may therefore be shared between the first heating arrangement and the second heating arrangement. Embodiments of this arrangement are disclosed in more detail below. Advantageously, a singular heater may simplify manufacture of the aerosol-generating device compared to two separate heaters, whilst maintaining the ability of the singular heater to heat different zones within an aerosol-forming substrate of an aerosol-generating article coupled to the device.

The control system may be configured to prevent the supply of power to the second heating arrangement when power is supplied to the first heating arrangement. The control system may be configured to prevent the supply of power to the first heating arrangement when power is supplied to the second heating arrangement. The control system may be configured to prevent simultaneous supply of power to the first heating arrangement and the second heating arrangement. Advantageously, this may reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours. Additionally, this may also reduce the maximum current drawn from the power supply system. This may otherwise result in a reduced power source lifespan or capacity, which is detrimental to use of the aerosolgenerating device, or may otherwise result in the power source overheating, which may present a danger to the integrity of the power source. This is particularly the case when the power supply system comprises only one power supply.

The control system may be configured to supply power to the first heating arrangement and the second heating arrangement in an alternating fashion. The control system may be configured to supply power to one of the first heating arrangement and the second heating arrangement for a first time period, and supply power to the other of the first heating arrangement and the second heating arrangement for a second time period that does not overlap with the first time period. Advantageously, this may heat the aerosol-forming substrate more evenly, therefore reducing the risk of unintended and undesired burning of the aerosol-forming substrate using one of the heating arrangements.

The aerosol-generating device may comprise a chamber configured to removably receive the aerosol-generating article therein. The chamber may be cylindrical or substantially cylindrical in cross-section. The chamber may be configured to receive an aerosol-generating article comprising a cylindrical or substantially cylindrical cross-section therein.

Alternatively, the chamber may be substantially flat. For example, the chamber may comprise a length, a width, and a thickness. The length may be greater in magnitude than the width. The width may be greater in magnitude than the thickness. The chamber may be configured to receive a substantially flat aerosol-generating article therein. The chamber may be configured to receive a substantially planar aerosol-generating article therein. For example, the aerosol-generating article may comprise a length, a width, and a thickness. The length may be greater in magnitude than the width. The width may be greater in magnitude than the thickness.

The aerosol-generating device may be configured to generate aerosol from an aerosolforming substrate over a sustained period, typically more than 5 seconds and may extend to more than 30 seconds. In the context of an aerosol-generating device, or other device on which a user puffs to withdraw aerosol from the device, this means heating an aerosolforming article, or an aerosol-forming substrate of an aerosol-forming article, over a period containing a plurality of user puffs. The aerosol-generating device may therefore be configured to heat an aerosol-forming substrate of an aerosol-forming article using the first heating arrangement and the second heating arrangement over a period containing a plurality of user puffs, so that aerosol is continuously generated, independent of whether a user is puffing on the device or not. It is in this context that depletion of the substrate becomes a significant issue, and where heating an aerosol-forming substrate with a first and a second heating arrangement may be particularly beneficial. This is in contrast to flash heating, in which a separate substrate or portion of the substrate is heated for each user puff, so that no portion of the substrate is heated for more than one puff where a puff duration is approximately 2-3 seconds in length.

As used herein, the terms “puff” and “inhalation” are used interchangeably and are intended to mean the action of a user drawing an aerosol into their body through their mouth or nose. Inhalation includes the situation where an aerosol is drawn into the user’s lungs, and also the situation where an aerosol is only drawn into the user’s mouth or nasal cavity before being expelled from the user’s body.

Power may be provided to the first heating arrangement and second heating arrangement to ensure that the temperature of the aerosol-forming substrate does not fall below a minimum allowable temperature during a sustained period. The first heating arrangement may be configured to generate heat at an internal location or area within the chamber. The first heating arrangement may be configured to heat the aerosol-generating article from an internal location or area within the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber. The first heating arrangement may be configured to heat the aerosol-generating article from an internal location or area within an aerosol-forming substrate of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber. Advantageously, the device may therefore heat an internal portion of the aerosol-forming substrate, allowing for aerosol to be generated with better characteristics compared to a heating arrangement which solely heats the aerosol-forming substrate from an external location. Furthermore, the internal location at which heat is generated may be better insulated from the outside of the aerosol-generating device compared to a heating arrangement which solely heats the aerosol-forming substrate from an external location.

The first heating arrangement may comprise an internal resistive heating element. The internal resistive heating element may be configured to be located within the aerosol-forming substrate of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber.

The internal resistive heating element may be disposed within the chamber of the aerosol-generating device. The internal resistive heating element may comprise at least one blade, pin, or other penetrating structure configured to be inserted into the aerosol-forming substrate when the aerosol-generating article is received in the chamber. The at least one blade or pin may comprise at least one resistive heating track located on a polyimide substrate. Advantageously, the internal resistive heating element may therefore be reused for different aerosol-generating articles.

The control system may be configured to heat the internal resistive heating element to a temperature of at least 80°C. The control system may be configured to heat the internal resistive heating element to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

The first heating arrangement may comprise an inductor element. The inductor element may comprise an inductor coil. The inductor coil may comprise a helical inductor coil. The inductor coil may at least partially surround at least part of the chamber. The inductor element may be configured to inductively heat at least one internal susceptor element.

The aerosol-generating device may comprise the at least one internal susceptor element. For example, the at least one internal susceptor element may be disposed within the chamber of the aerosol-generating device. The at least one internal susceptor element may comprise at least one pin configured to be inserted into the aerosol-forming substrate when the aerosol-generating article is received in the chamber. The at least one internal susceptor element may comprise at least one blade configured to be inserted into the aerosol-forming substrate when the aerosol-generating article is received in the chamber. Advantageously, the internal susceptor element may therefore be reused for different aerosol-generating articles.

Alternatively or additionally, the aerosol-generating article may comprise the at least one internal susceptor element. The possible form of such an at least one internal susceptor element is discussed below with respect to the aerosol-generating article. Advantageously, the aerosol-generating article comprising the at least one internal susceptor element simplifies the manufacture of the aerosol-generating device, and the form of the at least one internal susceptor element may be customised dependent on the type or size or composition of aerosol-generating article.

The first switching circuitry arrangement may be configured to supply an alternating current to the inductor element. The first switching circuitry arrangement may comprise a DC/AC converter. The DC/AC converter may be configured to convert a direct current supplied from the power supply system to an alternating current to be supplied to the inductor element. The DC/AC converter may comprise a half-bridge or a full-bridge DC/AC converter. The first switching circuitry arrangement may comprise a Class-E power amplifier including a first transistor switch and an LC load network. Advantageously, the power supply system need not comprise a supply of alternating current. In embodiments where the power supply system comprises only one power supply, the one power supply may still be used to supply power to both the first and second heating arrangements.

The first heating arrangement may comprise a dielectric heater configured to dielectrically heat the aerosol-forming substrate.

The dielectric heater may comprise two at least partially opposing electrodes having the aerosol-forming substrate therebetween that form a load capacitor that are fed by an alternating voltage. The alternating voltage can be generated by an oscillation circuit, the oscillation circuit comprising a switching unit and a resonant feedback loop connected across the switching unit. The resonant feedback loop may comprise two electrical contacts configured to interconnect with an electrode arrangement that forms a load capacitor for dielectrically heating the aerosol-forming substrate. The electrode arrangement may comprise a first and a second electrode. The first and second electrodes may each comprise electrode plates. The first and second electrodes may be positioned on opposite sides of the chamber to one another. The first and second electrodes may be configured to directly contact the aerosol-generating article when the aerosol-generating article is received within the chamber. Advantageously, dielectric heating of the aerosol-forming substrate results in even heating of the aerosol-forming substrate, particularly when the aerosol-generating article is substantially flat.

The first switching circuitry arrangement may be configured to supply a direct current to the dielectric heater to dielectrically heat an aerosol-generating article. The oscillation circuit may convert the direct current to an oscillating voltage across the first and second electrodes.

The first switching circuitry arrangement may comprise a switch. The first switching circuitry arrangement may comprise a Field Effect Transistor. The first switching circuitry arrangement may comprise a MOSFET. Advantageously, such configurations allow for the control system to control the supply of power to the first heating arrangement in a straightforward manner. The second heating arrangement may be configured to generate heat at an external location outside of the chamber. The second heating arrangement may be configured to heat the aerosol-generating article from an external location outside of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber. Advantageously, the device may therefore heat an external portion of the aerosol-forming substrate, allowing for aerosol to be generated with better characteristics compared to a heating arrangement which solely heats the aerosol-forming substrate from an internal location.

The second heating arrangement may comprise an external heating element. The second heating arrangement may comprise an external resistive heating element, for example an external resistive sleeve or other surrounding or partially surrounding structure around the chamber. The second heating arrangement may comprise an infrared heating element, for example an infrared heating element in the form of a sleeve or other surrounding or partially surrounding structure around the chamber, for example, the sleeve having a first outer infrared radiation generating layer, and a second inner infrared absorbing layer for generating heat by infrared absorption. The second heating arrangement may comprise a combination of an infrared heating element and a resistive heating element.

The external resistive heating element may be disposed around the chamber of the aerosol-generating device. The external resistive heating element may comprise a resistive heating sleeve. The resistive heating sleeve may at least partially, or fully, surround at least a portion of the chamber. Advantageously, the aerosol-forming substrate may therefore be heated about an entire circumference of the aerosol-forming substrate.

The resistive heating sleeve may comprise a resistive heating track printed on a polyimide substrate. The control system may be configured to heat the external heating element to a temperature of at least 80°C. The control system may be configured to heat the external heating element to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

In embodiments in which the first heating arrangement comprises an inductor element configured to heat an internal susceptor element, the second heating arrangement may comprise the same inductor element. The inductor element may be disposed around the chamber of the aerosol-generating device. The inductor element may comprise a resistive heating sleeve. The resistive heating sleeve may at least partially, or fully, surround at least a portion of the chamber. The first switching circuitry arrangement may be configured to supply a first alternating current to the inductor element. The second switching circuitry arrangement may be configured to supply a second alternating current to the inductor element. The second alternating current may have a different frequency to the first alternating current. The first alternating current may be configured to inductively heat the internal susceptor element. The second alternating current may be configured to resistively heat the inductor element. Alternatively of additionally, the second switching circuitry arrangement may be configured to supply a direct current to the inductor element, the direct current may be configured to resistively heat the inductor element.

Advantageously, a single inductor element may therefore provide for both internal and external heating of an aerosol-generating article, by acting as both the first heating arrangement and the second heating arrangement.

The control system may be configured to heat the inductor element to a temperature of at least 80°C. The control system may be configured to heat the inductor element to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

In embodiments in which the first heating arrangement comprises a dielectric heater configured to dielectrically heat an aerosol-generating article, the second heating arrangement may comprise the same dielectric heater. The dielectric heater may be disposed in or around the chamber of the aerosol-generating device. The first switching circuitry arrangement may be configured to supply a direct current to the dielectric heater to dielectrically heat an aerosol-generating article. The second switching circuitry arrangement may be configured to supply an alternating current or a direct current to one or both of the two electrodes of the dielectric heater to resistively heat the dielectric heater.

Alternatively or additionally, the dielectric heater may vary the frequency of the oscillating voltage supplied across the first and second electrodes in order to adjust an amount of resistive heating in the first and second electrodes.

Advantageously, a single dielectric heater may therefore provide for both internal and external heating of an aerosol-generating article, by acting as both the first heating arrangement and the second heating arrangement.

The control system may be configured to heat the dielectric heater to a temperature of at least 80°C. The control system may be configured to heat the dielectric heater to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

In embodiments in which the first heating arrangement comprises an internal resistive heating element or a dielectric heater, and the second heating arrangement may comprise an inductor element. The inductor element may comprise an inductor coil. The inductor coil may comprise a helical inductor coil. The inductor coil may at least partially surround at least part of the chamber. The aerosol-generating device may comprise at least one external susceptor element.

The inductor element may be configured to inductively heat the at least one external susceptor element. The at least one external susceptor element may be disposed outside of the chamber of the aerosol-generating device. The external susceptor element may at least partially surround at least part of the chamber. The external susceptor element may be configured not to penetrate the aerosol-generating article when the aerosol-generating article is coupled to the device. For example, the external susceptor element may be configured not to penetrate the aerosol-generating article when the aerosol-generating article is received within the chamber. The external susceptor element may comprise a susceptor sleeve.

The second switching circuitry arrangement may be configured to supply an alternating current to the inductor element. The second switching circuitry arrangement may comprise a DC/AC converter. The DC/AC converter may be configured to convert a direct current supplied from the power supply system to an alternating current to be supplied to the inductor element. The DC/AC converter may comprise a half-bridge or a full-bridge DC/AC converter. The second switching circuitry arrangement may comprise a Class-E power amplifier including a first transistor switch and an LC load network. Advantageously, the power supply system need not comprise a supply of alternating current. In embodiments where the power supply system comprises only one power supply, the one power supply may still be used to supply power to both the first and second heating arrangements.

The second switching circuitry arrangement may comprise a switch. The second switching circuitry arrangement may comprise a Field Effect Transistor. The second switching circuitry arrangement may comprise a MOSFET. Advantageously, such configurations allow for the control system to control the supply of power to the second heating arrangement in a straightforward manner.

According to the present disclosure, there is also provided an aerosol-generating system. The aerosol-generating system may comprise an aerosol-generating device according to the present disclosure. For example, the aerosol-generating device may comprise a first heating arrangement. The aerosol-generating device may comprise a second heating arrangement. The first heating arrangement may be configured for heating the aerosol-generating article when in use. The second heating arrangement may be configured for heating the aerosolgenerating article when in use. The first heating arrangement and the second heating arrangement may be electrically connected to a first switching circuitry arrangement and a second switching circuitry arrangement respectively. The aerosol-generating device may comprise a power supply system configured to supply power to the first heating arrangement and the second heating arrangement. The aerosol-generating device may comprise a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively. The aerosolgenerating system may comprise an aerosol-generating article comprising an aerosolforming substrate. The aerosol-generating article may be received in a chamber of the aerosol generating device.

According to a second aspect of the present disclosure, there is provided an aerosolgenerating system comprising an aerosol-generating device according to the present disclosure, and an aerosol-generating article comprising an aerosol-forming substrate, wherein the aerosol-generating article is received in a chamber of the aerosol generating device. Advantageously, a first switching circuitry arrangement and a separate second switching circuitry arrangement allows for the control system to exercise separate control of the operation of, and power supply to, the first heating arrangement and the second heating arrangement. Such a configuration also facilitates the ability for the control system to ensure that power is not supplied from the power supply system to both the first heating arrangement and the second heating arrangement concurrently. Therefore, this configuration may reduce the risk that the power supply system is overloaded as too much current is drawn from the power supply system. This in turn may result in a longer lifespan of the power supply system, or reduce the risk of the power supply system overheating.

The aerosol-generating article may comprise at least one susceptor. The aerosol-forming substrate may comprise the at least one susceptor. Advantageously, the aerosol-forming substrate may therefore be internally heated by a device comprising an induction element.

The at least one susceptor may be in the form of elongated particles. The elongated particles may be aligned with a longitudinal direction of the aerosol-generating article. The elongated particles may be aligned with a longitudinal direction of the aerosol-forming substrate. The at least one susceptor may be in the form of one or more strips of susceptor material. The aerosol-generating article may comprise one or more strips of aerosol-forming substrate laminated with one on more strips of susceptor material.

The aerosol-generating device may comprise at least one susceptor. The at least one susceptor may be configured to be inserted into the aerosol-generating substrate when the aerosol-generating article is received in the chamber. The aerosol-forming substrate may comprise tobacco material. The aerosol-generating article may be configured to be directly inhaled upon by a user during use.

According to the present disclosure, there is also provided a method of controlling an aerosol-generating system to generate an aerosol from an aerosol-generating article. The aerosol-generating system may comprise an aerosol-generating device. The aerosolgenerating system may comprise an aerosol-generating device according to the present disclosure. The aerosol-generating device may comprise a first heating arrangement and a second heating arrangement configured for heating the aerosol-generating article when in use. The first heating arrangement and the second heating arrangement may be electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively. The aerosol-generating device may comprise a power supply system configured to supply power to the first heating arrangement and the second heating arrangement. The aerosol-generating device may comprise a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively. The aerosol-generating system may comprise an aerosol-generating article comprising an aerosol-forming substrate. The aerosolgenerating article may be received in a chamber of the aerosol generating device. The method may comprise the step of controlling the supply of power from the power supply system to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article. The method may comprise the step of controlling the supply of power from the at least one power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article.

According to a third aspect of the present disclosure, there is provided a method of controlling an aerosol-generating system to generate an aerosol from an aerosol-generating article, the aerosol-generating system comprising: an aerosol-generating device, the aerosolgenerating device comprising a first heating arrangement and a second heating arrangement configured for heating the aerosol-generating article when in use, the first heating arrangement and the second heating arrangement electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively; a power supply system configured to supply power to the first heating arrangement and the second heating arrangement, and a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively, the aerosol-generating system further comprising an aerosolgenerating article comprising an aerosol-forming substrate, wherein the aerosol-generating article is received in a chamber of the aerosol generating device, wherein the method comprises the steps of: controlling the supply of power from the power supply system to the first heating arrangement via the first switching circuitry arrangement to heat the aerosolgenerating article, and controlling the supply of power from the at least one power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article. Advantageously, a first switching circuitry arrangement and a separate second switching circuitry arrangement allows for the control system to exercise separate control of the operation of, and power supply to, the first heating arrangement and the second heating arrangement. Such a configuration also facilitates the ability for the control system to ensure that power is not supplied from the power supply system to both the first heating arrangement and the second heating arrangement concurrently. Therefore, this configuration may reduce the risk that the power supply system is overloaded as too much current is drawn from the power supply system. This in turn may result in a longer lifespan of the power supply system, or reduce the risk of the power supply system overheating.

The control system may include a first control unit. The first control unit may be configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement. The first control unit may be configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement.

The method may comprise the step of the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article, and the first control unit controlling the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article. Advantageously, only a single power supply and a single control unit is therefore required to power and control the operation of two heating arrangements.

The method may comprise the first switching circuitry arrangement providing a first feedback signal to the first control unit. The method may comprise the second switching circuitry arrangement providing a second feedback signal to the first control unit. The method may comprise the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal. The method may comprise the first control unit controlling the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal. Advantageously, the control system may therefore accurately control the amount of heating by the first heating arrangement and by the second heating arrangement, and in use such control may allow for better aerosol characteristics from an aerosol-forming substrate to be achieved, and reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours.

The method may comprise the step of the first power supply supplying power to the first control unit. Advantageously, by the first power supply supplying power to the first control unit, a further dedicated power supply for the first control unit is not required, simplifying the design of the device. The control system may include a second control unit configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement. The second control unit may comprise a microcontroller or a microprocessor. The method may comprise the step of the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article. The method may comprise the step of the second control unit controlling the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article. Advantageously, only a single power supply is therefore required to power the operation of two heating arrangements.

The method may comprise the first switching circuitry arrangement providing a first feedback signal to the first control unit. The method may comprise the second switching circuitry arrangement providing a second feedback signal to the second control unit. The method may comprise the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal. The method may comprise the second control unit controlling the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal. Advantageously, the control system may therefore accurately control the amount of heating by the first heating arrangement and by the second heating arrangement, and in use such control may allow for better aerosol characteristics from an aerosol-forming substrate to be achieved, and reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours.

The method may further comprise the first control unit providing a control signal to the second control unit. The method may further comprise the second control unit controlling the supply of power from the first power supply to the second heating arrangement dependent on the control signal. The control signal may be an electrical control signal. For example, the control signal may comprise one or more of a voltage, a current, or a conductance. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. Such an arrangement may synchronise the operation of the first and second heating arrangements without the requirement of the first control unit and the second control unit to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the second control unit need not comprise any timing means. This simplifies the manufacture of the second control unit, and therefore of any such aerosol-generating device comprising said control system.

The method may further comprise the second control unit controlling the second switching circuitry arrangement to prevent the supply of power from the first power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement. Advantageously, the control circuitry may therefore avoid both the first and second heating arrangements being powered simultaneously.

The method may further comprise the second control unit providing a control signal to the first control unit. The method may further comprise the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the control signal. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. Such an arrangement may synchronise the operation of the first and second heating arrangements without the requirement of the first control unit and the second control unit to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the first control unit need not comprise any timing means. This simplifies the manufacture of the first control unit, and therefore of any such aerosol-generating device comprising said control system.

The method may further comprise the first control unit controlling the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the first power supply to the second heating arrangement. Advantageously, the control circuitry may therefore avoid both the first and second heating arrangements being powered simultaneously.

The method may further comprise the first power supply supplying power to the first control unit and the second control unit. Advantageously, by the first power supply supplying power to the first and second control units, a further dedicated power supply for the first and second control units is not required, simplifying the design of the device.

The power supply system may comprise a first power supply configured to supply power to the first heating arrangement and a second power supply configured to supply power to the second heating arrangement. The method may comprise the step of the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article. The method may comprise the step of the first control unit controlling the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article. Advantageously, by including dedicated power supplies for both the first heating arrangement and the second heating arrangement, the risk that the first heating arrangement and the second heating arrangement draw excessive current from the power supply system, for example when both heating arrangements are powered, is mitigated. Such an arrangement also allows for both the first heating arrangement and the second heating arrangement to be powered concurrently without drawing excessive current from the power supply system. The method may further comprise the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal. The method may further comprise the first control unit controlling the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal. Advantageously, the control system may therefore accurately control the amount of heating by the first heating arrangement and by the second heating arrangement, and in use such control may allow for better aerosol characteristics from an aerosol-forming substrate to be achieved, and reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours.

The method may further comprise one of the first power supply and the second power supply supplying power to the first control unit. Advantageously, a further dedicated power supply for the first control unit is not required, simplifying the design of the device.

The second control unit may be configured to control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement.

The method may comprise the step of the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article. The method may comprise the step of the second control unit controlling the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article. Advantageously, by separating the first and second power supply, first and second control unit, first and second switching arrangement, and first and second heating arrangement, the aerosol-generating device may be manufactured in a more modular fashion. For example, a first heating arrangement with a first switching arrangement, a first control unit and a first power supply may be manufactured separately to the rest of the components of the aerosol-generating device.

The method may further comprise the first switching circuitry arrangement providing a first feedback signal to the first control unit, and the second switching circuitry arrangement providing a second feedback signal to the second control unit.

The method may further comprise the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal. The method may further comprise the second control unit controlling the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal. Advantageously, the control system may therefore accurately control the amount of heating by the first heating arrangement and by the second heating arrangement, and in use such control may allow for better aerosol characteristics from an aerosol-forming substrate to be achieved, and reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours.

The method may further comprise the first control unit providing a control signal to the second control unit, and the second control unit controlling the supply of power from the second power supply to the second heating arrangement dependent on the control signal. The control signal may be an electrical control signal. For example, the control signal may comprise one or more of a voltage, a current, or a conductance. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. Such an arrangement may synchronise the operation of the first and second heating arrangements without the requirement of the first control unit and the second control unit to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the second control unit need not comprise any timing means. This simplifies the manufacture of the second control unit, and therefore of any such aerosol-generating device comprising said control system.

The method may further comprise the second control unit controlling the second switching circuitry arrangement to prevent the supply of power from the second power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement. Advantageously, the control circuitry may therefore avoid both the first and second heating arrangements being powered simultaneously.

The method may further comprise the second control unit providing a control signal to the first control unit, and the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the control signal. The control signal may be an electrical control signal. For example, the control signal may comprise one or more of a voltage, a current, or a conductance. Advantageously, the power supplied to the first and second heating arrangements may therefore be synchronised. Such an arrangement may synchronise the operation of the first and second heating arrangements without the requirement of the first control unit and the second control unit to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the first control unit need not comprise any timing means. This simplifies the manufacture of the first control unit, and therefore of any such aerosol-generating device comprising said control system.

The method may further comprise the first control unit controlling the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the second power supply to the second heating arrangement. Advantageously, the control circuitry may therefore avoid both the first and second heating arrangements being powered simultaneously. The method may further comprise the first power supply supplying power to the first control unit, and the second power supply supplying power to the second control unit. The method may further comprise the second power supply supplying power to the first control unit, and the first power supply supplying power to the second control unit. Advantageously, a further dedicated power supply for the first and second control units is not required, simplifying the design of the device.

The method may further comprise the control system preventing the supply of power to the second heating arrangement when power is supplied to the first heating arrangement. The method may further comprise the control system preventing the supply of power to the first heating arrangement when power is supplied to the second heating arrangement. The method may further comprise the control system preventing simultaneous supply of power to the first heating arrangement and the second heating arrangement. Advantageously, this may reduce the risk of unintended and undesired burning of an aerosol-forming substrate close to the heat source, which can give rise to the generation of undesirable compounds and flavours. Additionally, this may also reduce the maximum current drawn from the power supply system. This may otherwise result in a reduced power source lifespan or capacity, which is detrimental to use of the aerosol-generating device, or may otherwise result in the power source overheating, which may present a danger to the integrity of the power source. This is particularly the case when the power supply system comprises only one power supply.

The method may further comprise the control system supplying power to the first heating arrangement and the second heating arrangement in an alternating fashion. The method may further comprise the control system supplying power to one of the first heating arrangement and the second heating arrangement for a first time period, and supplying power to the other of the first heating arrangement and the second heating arrangement for a second time period that does not overlap with the first time period. Advantageously, this may heat the aerosol-forming substrate more evenly, therefore reducing the risk of unintended and undesired burning of the aerosol-forming substrate using one of the heating arrangements.

The method may comprise generating aerosol from an aerosol-forming substrate over a sustained period, typically more than 5 seconds and may extend to more than 30 seconds. In the context of an aerosol-generating device, or other device on which a user puffs to withdraw aerosol from the device, this means heating an aerosol-forming article, or an aerosol-forming substrate of an aerosol-forming article, over a period containing a plurality of user puffs. The method may therefore comprise heating an aerosol-forming substrate of an aerosol-forming article using the first heating arrangement and the second heating arrangement over a period containing a plurality of user puffs, so that aerosol is continuously generated, independent of whether a user is puffing on the device or not. It is in this context that depletion of the substrate becomes a significant issue, and where heating an aerosolforming substrate with a first and a second heating arrangement may be particularly beneficial. This is in contrast to flash heating, in which a separate substrate or portion of the substrate is heated for each user puff, so that no portion of the substrate is heated for more than one puff where a puff duration is approximately 2-3 seconds in length.

The method may comprise providing power to the first heating arrangement and second heating arrangement to ensure that the temperature of the aerosol-forming substrate does not fall below a minimum allowable temperature during a sustained period.

The method may further comprise the first heating arrangement generating heat from an internal location within the chamber. The method may further comprise the first heating arrangement heating the aerosol-generating article from an internal location within the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber. The method may further comprise the first heating arrangement heating the aerosol-generating article from an internal location within an aerosol-forming substrate of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber. Advantageously, the device may therefore heat an internal portion of the aerosol-forming substrate, allowing for aerosol to be generated with better characteristics compared to a heating arrangement which solely heats the aerosol-forming substrate from an external location. Furthermore, the internal location at which heat is generated may be better insulated from the outside of the aerosol-generating device compared to a heating arrangement which solely heats the aerosol-forming substrate from an external location.

The first heating arrangement may comprise an internal resistive heating element. The method may further comprise the control system heating the internal resistive heating element to a temperature of at least 80°C. The method may further comprise the control system heating the internal resistive heating element to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

The first heating arrangement may comprise an inductor element. The method may further comprise the inductor element inductively heating at least one internal susceptor element. The first heating arrangement may comprise a dielectric heater. The method may further comprise the dielectric heater dielectrically heating the aerosol-forming substrate.

The method may further comprise the second heating arrangement generating heat from an external location outside of the chamber. The method may further comprise the second heating arrangement heating the aerosol-generating article from an external location outside of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber. Advantageously, the device may therefore heat an external portion of the aerosol-forming substrate, allowing for aerosol to be generated with better characteristics compared to a heating arrangement which solely heats the aerosol-forming substrate from an internal location.

The second heating arrangement may comprise an external heating element. The second heating arrangement may comprise an external resistive heating element, for example an external resistive sleeve or other surrounding or partially surrounding structure around the chamber. The second heating arrangement may comprise an infrared heating element, for example an infrared heating element in the form of a sleeve or other surrounding or partially surrounding structure around the chamber, for example, the sleeve having a first outer infrared radiation generating layer, and a second inner infrared absorbing layer for generating heat by infrared absorption. The second heating arrangement may comprise a combination of an infrared heating element and a resistive heating element. The method may further comprise the control system heating the external heating element to a temperature of at least 80°C. The method may further comprise the control system heating the external heating element to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

In embodiments in which the first heating arrangement comprises an inductor element configured to heat an internal susceptor element, the second heating arrangement may comprise the same inductor element acting as a resistive heater. The method may further comprise the first switching circuitry arrangement supplying a first alternating current to the inductor element. The method may further comprise the second switching circuitry arrangement supplying a second alternating current to the inductor element. The second alternating current may have a different frequency to the first alternating current. The method may further comprise the first alternating current inductively heating the internal susceptor element. The method may further comprise the second alternating current resistively heating the inductor element. Alternatively or additionally, the method may further comprise the second switching circuitry arrangement supplying a direct current to the inductor element. The method may further comprise the direct current resistively heating the inductor element. Advantageously, a single inductor element may therefore provide for both internal and external heating of an aerosol-generating article, by acting as both the first heating arrangement and the second heating arrangement.

The method may further comprise the control system heating the inductor element to a temperature of at least 80°C. The method may further comprise the control system heating the inductor element to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

In embodiments in which the first heating arrangement comprises a dielectric heater configured to dielectrically heat an aerosol-generating article, the second heating arrangement may comprise the same dielectric heater. The dielectric heater may be disposed in or around the chamber of the aerosol-generating device. The method may further comprise the first switching circuitry arrangement supplying a direct current to the dielectric heater to dielectrically heat an aerosol-generating article. The method may further comprise the second switching circuitry arrangement supplying an alternating current or a direct current to one or both of the two electrodes of the dielectric heater to resistively heat the dielectric heater.

Alternatively or additionally, the method may further comprise the dielectric heater varying the frequency of the oscillating voltage supplied across the first and second electrodes in order to adjust an amount of resistive heating in the first and second electrodes.

The method may further comprise the control system heating the dielectric heater to a temperature of at least 80°C. The method may further comprise the control system heating the dielectric heater to a temperature of no more than 400°C. Advantageously, such temperatures have been found to achieve desirable aerosol characteristics, whilst avoiding burning of the aerosol-forming substrate.

In embodiments in which the first heating arrangement comprises an internal resistive heating element or a dielectric heater, the second heating arrangement may comprise an inductor element. The aerosol-generating device may comprise at least one external susceptor element. The method may further comprise the inductor element inductively heating the at least one external susceptor element.

As used herein, the term “aerosol-generating device” is used to describe a device that interacts with an aerosol-forming substrate to generate an aerosol. Preferably, the aerosol-generating device is a smoking device that interacts with an aerosol-forming substrate to generate an aerosol that is directly inhalable into a user’s lungs thorough the user's mouth.

As used herein, the term “aerosol-forming substrate” refers to a substrate consisting of or comprising an aerosol-forming material that is capable of releasing volatile compounds upon heating to generate an aerosol.

Preferably, the aerosol-forming substrate comprises nicotine. More preferably, the aerosol-forming substrate comprises tobacco. Alternatively or in addition, the aerosolforming substrate may comprise a non-tobacco containing aerosol-forming material.

If the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosolforming substrate may comprise, for example, one or more of: powder, granules, pellets, shreds, strands, strips, or sheets containing one or more of: herb leaf, tobacco leaf, tobacco ribs, expanded tobacco and homogenised tobacco.

Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavour compounds, which are released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain one or more capsules that, for example, include additional tobacco volatile flavour compounds or non-tobacco volatile flavour compounds and such capsules may melt during heating of the solid aerosol-forming substrate.

Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may take the form of powder, granules, pellets, shreds, strands, strips, or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier in the form of, for example, a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern in order to provide a non-uniform flavour delivery during use.

In a preferred embodiment, the aerosol-forming substrate comprises homogenised tobacco material. As used herein, the term “homogenised tobacco material” refers to a material formed by agglomerating particulate tobacco.

Preferably, the aerosol-forming substrate comprises a gathered sheet of homogenised tobacco material. As used herein, the term “sheet” refers to a laminar element having a width and length substantially greater than the thickness thereof. As used herein, the term “gathered” is used to describe a sheet that is convoluted, folded, or otherwise compressed or constricted substantially transversely to the longitudinal axis of the aerosolgenerating article. Preferably, the aerosol-forming substrate comprises an aerosol former. As used herein, the term “aerosol former” is used to describe any suitable known compound or mixture of compounds that, in use, facilitates formation of an aerosol and that is substantially resistant to thermal degradation at the operating temperature of the aerosolgenerating article.

Suitable aerosol-formers are known in the art and include, but are not limited to: polyhydric alcohols, such as propylene glycol, triethylene glycol, 1 ,3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as propylene glycol, triethylene glycol, 1 ,3-butanediol and, most preferred, glycerine.

The aerosol-forming substrate may comprise a single aerosol former. Alternatively, the aerosol-forming substrate may comprise a combination of two or more aerosol formers.

The aerosol-generating device may be configured to generate aerosol from a liquid aerosol-forming substrate. In such embodiments, the aerosol-generating device may comprise a capillary wick in fluidic contact with a reservoir filled with a liquid aerosol-forming substrate. The first or second heating arrangement may be configured to preheat the wick when the aerosol-generating device is switched on by a user. The other of the first or second heating arrangement may be configured to heat the wick at times when the user puffs on the aerosol-generating device. The user puffing on the device may be detected by a pressure sensor or air flow sensor in fluid communication with an airflow pathway within the device, for example. The first and second heating arrangements may comprise two separate resistive heating coils wrapped around the wick. The first heating arrangement may comprise a resistive heating coil wrapped around the wick, and the second heating arrangement may comprise a resistive heating element upstream of the wick and first heating arrangement and configured to preheat air drawn to the wick when the user puffs of the device. The first and second heating arrangements may comprise any two heating arrangements as described herein. Any combination of the first heating arrangement, the second heating arrangement, the capillary wick, and the reservoir may be contained within a cartridge which is removably couplable to the rest of the aerosol-generating device. For example, all of the first heating arrangement, the second heating arrangement, the capillary wick, and the reservoir may be contained within a cartridge which is removably couplable to the rest of the aerosolgenerating device. In such an embodiment, the first heating arrangement and the second heating arrangement may be electrically connected to the first and second switching circuitry arrangements respectively when the cartridge is coupled to the rest of the aerosol-generating device.

As used herein, the term “susceptor” refers to an element comprising a material that is capable of converting the energy of a magnetic field into heat. When a susceptor is located in an alternating magnetic field, the susceptor is heated. Heating of the susceptor may be the result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

As used herein when referring to an aerosol-generating device, an aerosolgenerating article, a jacket, a sleeve, a heating arrangement or an inductor assembly, the term “longitudinal” may refer to the longest direction of any such component of an aerosolgenerating system. The term “longitudinal” may refer to the direction of extension of the component from a proximal end of the component to a distal end of the component.

As used herein, the term “winding axis” may refer to a straight axis or line about which a component is wound. For example, the term “winding axis” may refer to a straight axis or line about which a component is helically wound. All points of the wound component may be substantially equidistant from the winding axis.

As used herein, the term “sleeve” may refer to a component with a substantially hollow and substantially cylindrical shape. The component may comprise a lumen within the sleeve.

As used herein when referring to an aerosol-generating device, the terms “upstream” and “downstream” are used to describe the relative positions of components, or portions of components, of the aerosol-generating device in relation to the direction in which air flows through the aerosol-generating device during use thereof. Aerosol-generating devices according to the invention may comprise a proximal end through which, in use, an aerosol exits the device. The proximal end of the aerosol-generating device may also be referred to as the mouth end or the downstream end. The mouth end is downstream of the distal end. The distal end of the aerosol-generating device may also be referred to as the upstream end. Components, or portions of components, of the aerosol-generating device may be described as being upstream or downstream of one another based on their relative positions with respect to the airflow path of the aerosol-generating device. As used herein when referring to an aerosol-generating article, the terms “upstream” and “downstream” are used to describe the relative positions of components, or portions of components, of the aerosolgenerating article in relation to the direction in which air flows through the aerosol-generating article during use thereof. Aerosol-generating articles according to the invention may comprise a proximal end through which, in use, an aerosol exits the article. The proximal end of the aerosol-generating article may also be referred to as the mouth end or the downstream end. The mouth end is downstream of the distal end. The distal end of the aerosol-generating article may also be referred to as the upstream end. Components, or portions of components, of the aerosol-generating article may be described as being upstream or downstream of one another based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article. The front of a component, or portion of a component, of the aerosol-generating article is the portion at the end closest to the upstream end of the aerosol-generating article. The rear of a component, or portion of a component, of the aerosol-generating article is the portion at the end closest to the downstream end of the aerosol-generating article.

The invention is defined in the claims. However, below there is provided a non- exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Example Ex1 . An aerosol-generating device for generating aerosol from an aerosolgenerating article, the aerosol-generating device comprising; a first heating arrangement and a second heating arrangement configured for heating the aerosol-generating article when in use, the first heating arrangement and the second heating arrangement electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively; a power supply system configured to supply power to the first heating arrangement and the second heating arrangement, and a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively.

Example Ex2. An aerosol-generating device according to Example Ex1 , wherein the power supply system includes a first power supply configured to supply power to the first heating arrangement and the second heating arrangement.

Example Ex3. An aerosol-generating device according to Example Ex2, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively.

Example Ex4. An aerosol-generating device according to Example Ex3, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the first control unit.

Example Ex5. An aerosol-generating device according to Example Ex4, wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and control the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal. Example Ex6. An aerosol-generating device according to any one of Examples Ex3 to Ex5, wherein the first power supply is configured to supply power to the first control unit.

Example Ex7. An aerosol-generating device according to Example Ex2, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and includes a second control unit configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement.

Example Ex8. An aerosol-generating device according to Example Ex7, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the second control unit.

Example Ex9. An aerosol-generating device according to Example Ex8, wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and wherein the second control unit is configured to control the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal.

Example Ex10. An aerosol-generating device according to any one of Examples Ex7 to Ex9, wherein the first control unit is configured to provide a control signal to the second control unit and the second control unit is configured to control the supply of power from the first power supply to the second heating arrangement dependent on the control signal.

Example Ex1 1 . An aerosol-generating device according to Example Ex10, wherein the second control unit is configured to control the second switching circuitry arrangement to prevent the supply of power from the first power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement.

Example Ex12. An aerosol-generating device according to any one of Examples Ex7 to Ex9, wherein the second control unit is configured to provide a control signal to the first control unit and the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

Example Ex13. An aerosol-generating device according to Example Ex12, wherein the first control unit is configured to control the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the first power supply to the second heating arrangement.

Example Ex14. An aerosol-generating device according to any one of Examples Ex7 to Ex13, wherein the first power supply is configured to supply power to the first control unit and the second control unit.

Example Ex15. An aerosol-generating device according to any one of Examples Ex2 to Ex14, wherein the power supply system consists of the first power supply.

Example Ex16. An aerosol-generating device according to any one of Examples Ex2 to Ex15, wherein the first power supply includes only one DC power supply.

Example Ex17. An aerosol-generating device according to any one of Examples Ex2 to Ex16, wherein the first power supply includes only one battery cell.

Example Ex18. An aerosol-generating device according to any one of Examples Ex2 to Ex17, wherein the first power supply consists of one battery cell.

Example Ex19. An aerosol-generating device according to any one of Examples Ex2 to Ex18, wherein the first power supply includes a 18650 cell, a 14500 cell, or a 14650 cell.

Example Ex20. An aerosol-generating device according to Example Ex1 , wherein the power supply system comprises a first power supply configured to supply power to the first heating arrangement, and a second power supply configured to supply power to the second heating arrangement.

Example Ex21 . An aerosol-generating device according to Example Ex20, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement.

Example Ex22. An aerosol-generating device according to Example Ex21 , wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the first control unit.

Example Ex23. An aerosol-generating device according to Example Ex22, wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and control the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

Example Ex24. An aerosol-generating device according to any one of Examples Ex21 to Ex23, wherein one or both of the first power supply and the second power supply is configured to supply power to the first control unit. Example Ex25. An aerosol-generating device according to Example Ex20, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and includes a second control unit configured to control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement.

Example Ex26. An aerosol-generating device according to Example Ex25, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the second control unit.

Example Ex27. An aerosol-generating device according to Example Ex26, wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and wherein the second control unit is configured to control the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

Example Ex28. An aerosol-generating device according to any one of Examples Ex25 to Ex27, wherein the first control unit is configured to provide a control signal to the second control unit and the second control unit is configured to control the supply of power from the second power supply to the second heating arrangement dependent on the control signal.

Example Ex29. An aerosol-generating device according to Example Ex28, wherein the second control unit is configured to control the second switching circuitry arrangement to prevent the supply of power from the second power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement.

Example Ex30. An aerosol-generating device according to any one of Examples Ex25 to Ex27, wherein the second control unit is configured to provide a control signal to the first control unit and the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

Example Ex31 . An aerosol-generating device according to Example Ex30, wherein the first control unit is configured to control the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the second power supply to the second heating arrangement. Example Ex32. An aerosol-generating device according to any one of Examples Ex25 to Ex31 , wherein the first power supply is configured to supply power to the first control unit, and wherein the second power supply is configured to supply power to the second control unit.

Example Ex33. An aerosol-generating device according to any one of Examples Ex25 to Ex31 , wherein the second power supply is configured to supply power to the first control unit, and wherein the first power supply is configured to supply power to the second control unit.

Example Ex34. An aerosol-generating device according to any one of Examples Ex20 to Ex33, wherein the first power supply is not configured to supply power to the second heating arrangement, and the second power supply is not configured to supply power to the first heating arrangement.

Example Ex35. An aerosol-generating device according to Example any one of Examples Ex20 to Ex34, wherein the power supply system consists of the first power supply and the second power supply.

Example Ex36. An aerosol-generating device according to any one of Examples Ex20 to Ex35, wherein both the first power supply and the second power supply include only one DC power supply each.

Example Ex37. An aerosol-generating device according to any one of Examples Ex20 to Ex36, wherein both the first power supply and the second power supply include only one battery cell each.

Example Ex38. An aerosol-generating device according to any one of Examples Ex20 to Ex37, wherein both the first power supply and the second power supply consist of one battery cell each.

Example Ex39. An aerosol-generating device according to any one of Examples Ex20 to Ex38, wherein each of the first power supply and the second power supply include a 18650 cell, a 14500 cell, or a 14650 cell.

Example Ex40. An aerosol-generating device according to any one of Examples Ex20 to Ex39, wherein the first power supply and the second power supply are packaged together in a single power supply unit.

Example Ex41 . An aerosol-generating device according to any preceding Example, wherein the first heating arrangement is a first heater, and the second heating arrangement is a second heater.

Example Ex42. An aerosol-generating device according to any preceding Example, wherein a singular heater comprises the first heating arrangement and the second heating arrangement. Example Ex43. An aerosol-generating device according to any preceding Example, wherein the control system is configured to prevent the supply of power to the second heating arrangement when power is supplied to the first heating arrangement.

Example Ex44. An aerosol-generating device according to any preceding Example, wherein the control system is configured to prevent the supply of power to the first heating arrangement when power is supplied to the second heating arrangement.

Example Ex45. An aerosol-generating device according to any preceding Example, wherein the control system is configured to prevent simultaneous supply of power to the first heating arrangement and the second heating arrangement.

Example Ex46. An aerosol-generating device according to any preceding Example, wherein the control system is configured to supply power to the first heating arrangement and the second heating arrangement in an alternating fashion.

Example Ex47. An aerosol-generating device according to any preceding Example, wherein the control system is configured to supply power to one of the first heating arrangement and the second heating arrangement for a first time period, and supply power to the other of the first heating arrangement and the second heating arrangement for a second time period that does not overlap with the first time period.

Example Ex48. An aerosol-generating device according to any preceding Example, wherein the aerosol-generating device comprises a chamber configured to removably receive the aerosol-generating article therein.

Example Ex49. An aerosol-generating device according to any preceding Example, wherein the first and second feedback signals comprise at least one of a voltage, a current or a conductance.

Example Ex50. An aerosol-generating device according to any preceding Example, wherein the first feedback signal is dependent on a temperature of the first heating arrangement.

Example Ex51. An aerosol-generating device according to any preceding Example, wherein the second feedback signal is dependent on a temperature of the second heating arrangement.

Example Ex52. An aerosol-generating device according to any preceding Example, wherein the first feedback signal is dependent on a temperature of a susceptor coupled to the first heating arrangement.

Example Ex53. An aerosol-generating device according to any preceding Example, wherein the second feedback signal is dependent on a temperature of a susceptor coupled to the second heating arrangement. Example Ex54. An aerosol-generating device according to any preceding Example, wherein the first heating arrangement is configured to generate heat at an internal location within the chamber.

Example Ex55. An aerosol-generating device according to any preceding Example, wherein the first heating arrangement is configured to heat the aerosol-generating article from an internal location within the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber.

Example Ex56. An aerosol-generating device according to any preceding Example, wherein the first heating arrangement is configured to heat the aerosol-generating article from an internal location within an aerosol-forming substrate of the aerosolgenerating article when at least a portion of the aerosol-generating article is received within the chamber.

Example Ex57. An aerosol-generating device according to any preceding Example, wherein the first heating arrangement comprises an internal resistive heating element.

Example Ex58. An aerosol-generating device according to Example Ex57, wherein the internal resistive heating element is disposed within the chamber of the aerosolgenerating device.

Example Ex59. An aerosol-generating device according to Example Ex57 or Ex58, wherein the internal resistive heating element comprises at least one blade or pin configured to be inserted into the aerosol-forming substrate when the aerosolgenerating article is received in the chamber.

Example Ex60. An aerosol-generating device according to Example Ex59, wherein the at least one blade or pin comprises at least one resistive heating track located on a polyimide substrate.

Example Ex61 . An aerosol-generating device according to any one of Examples Ex57 to Ex60, wherein the control system is configured to heat the internal resistive heating element to a temperature of at least 80°C.

Example Ex62. An aerosol-generating device according to any one of Examples Ex57 to Ex61 , wherein the control system is configured to heat the internal resistive heating element to a temperature of no more than 400°C.

Example Ex63. An aerosol-generating device according to any one of Examples Ex1 to Ex56, wherein the first heating arrangement comprises an inductor element.

Example Ex64. An aerosol-generating device according to Example Ex63, wherein the inductor element comprises an inductor coil.

Example Ex65. An aerosol-generating device according to Example Ex63 or Ex64, wherein the inductor coil comprises a helical inductor coil. Example Ex66. An aerosol-generating device according to any one of Examples Ex63 to Ex65, wherein the inductor element is configured to inductively heat at least one internal susceptor element.

Example Ex67. An aerosol-generating device according to Example Ex66, wherein the aerosol-generating device comprises the at least one internal susceptor element.

Example Ex68. An aerosol-generating device according to Example Ex66 or Ex67, wherein the at least one internal susceptor element is disposed within the chamber of the aerosol-generating device.

Example Ex69. An aerosol-generating device according to any one of Examples Ex66 to Ex68, wherein the at least one internal susceptor element comprises at least one pin configured to be inserted into the aerosol-forming substrate when the aerosolgenerating article is received in the chamber.

Example Ex70. An aerosol-generating device according to any one of Examples Ex66 to Ex69, wherein the at least one internal susceptor element comprises at least one blade configured to be inserted into the aerosol-forming substrate when the aerosolgenerating article is received in the chamber.

Example Ex71 . An aerosol-generating device according to Example Ex66, wherein the aerosol-generating article comprises the at least one internal susceptor element.

Example Ex72. An aerosol-generating device according to any one of Examples Ex63 to Ex71 , wherein the first switching circuitry arrangement comprises a DC/AC converter, the DC/AC converter configured to convert a direct current supplied from the power supply system to an alternating current to be supplied to the inductor element.

Example Ex73. An aerosol-generating device according to any one of Examples Ex63 to Ex72, wherein the first switching circuitry arrangement comprises a Class-E power amplifier including a first transistor switch and an LC load network.

Example Ex74. An aerosol-generating device according to any one of Examples Ex1 to Ex56, wherein the first heating arrangement comprises a dielectric heater configured to dielectrically heat the aerosol-forming substrate.

Example Ex75. An aerosol-generating device according to Example Ex74, wherein the dielectric heater comprises an oscillation circuit, the oscillation circuit comprising a switching unit and a resonant feedback loop connected across the switching unit.

Example Ex76. An aerosol-generating device according to Example Ex75, wherein the resonant feedback loop comprises two electrical contacts configured to interconnect with an electrode arrangement that forms a load capacitor for dielectrically heating the aerosol-forming substrate. Example Ex77. An aerosol-generating device according to any preceding Example, wherein the first switching circuitry arrangement comprises a switch.

Example Ex78. An aerosol-generating device according to any preceding Example, wherein the first switching circuitry arrangement comprises a Field Effect Transistor.

Example Ex79. An aerosol-generating device according to any preceding Example, wherein the first switching circuitry arrangement comprises a MOSFET.

Example Ex80. An aerosol-generating device according to any preceding Example, wherein the second heating arrangement is configured to generate heat at an external location outside of the chamber.

Example Ex81. An aerosol-generating device according to any preceding Example, wherein the second heating arrangement is configured to heat the aerosol-generating article from an external location outside of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber.

Example Ex82. An aerosol-generating device according to any preceding Example, wherein the second heating arrangement comprises an external resistive heating element.

Example Ex83. An aerosol-generating device according to Example Ex82, wherein the external resistive heating element is disposed around the chamber of the aerosolgenerating device.

Example Ex84. An aerosol-generating device according to Example Ex82 or Ex83, wherein the external resistive heating element comprises a resistive heating sleeve.

Example Ex85. An aerosol-generating device according to Example Ex84, wherein the resistive heating sleeve comprises a resistive heating track printed on a polyimide substrate.

Example Ex86. An aerosol-generating device according to any one of Examples Ex82 to Ex85, wherein the control system is configured to heat the external resistive heating element to a temperature of at least 80°C.

Example Ex87. An aerosol-generating device according to any one of Examples Ex82 to Ex86, wherein the control system is configured to heat the external resistive heating element to a temperature of no more than 400°C.

Example Ex88. An aerosol-generating device according to any one of Examples Ex1 to Ex62, wherein the first heating arrangement comprises an internal resistive heating element or a dielectric heater, and wherein the second heating arrangement comprises an inductor element.

Example Ex89. An aerosol-generating device according to Example Ex88, wherein the inductor element comprises an inductor coil. Example Ex90. An aerosol-generating device according to Example Ex89, wherein the inductor coil comprises a helical inductor coil.

Example Ex91 . An aerosol-generating device according to any one of Examples Ex88 to Ex90, wherein the aerosol-generating device comprises at least one external susceptor element, and wherein the inductor element is configured to inductively heat the at least one external susceptor element.

Example Ex92. An aerosol-generating device according to Example Ex91 , wherein the at least one external susceptor element is disposed outside of the chamber of the aerosol-generating device.

Example Ex93. An aerosol-generating device according to Example Ex91 or Ex92, wherein the external susceptor element comprises a susceptor sleeve.

Example Ex94. An aerosol-generating device according to any one of Examples Ex88 to Ex93, wherein the second switching circuitry arrangement comprises a DC/AC converter, the DC/AC converter configured to convert a direct current supplied from the power supply system to an alternating current to be supplied to the inductor element.

Example Ex95. An aerosol-generating device according to Example Ex94, wherein the DC/ AC converter comprises a half-bridge or a full-bridge DC/ AC converter.

Example Ex96. An aerosol-generating device according to any one of Examples Ex88 to Ex95, wherein the second switching circuitry arrangement comprises a Class-E power amplifier including a first transistor switch and an LC load network.

Example Ex97. An aerosol-generating device according to any preceding Example, wherein the second switching circuitry arrangement comprises a switch.

Example Ex98. An aerosol-generating device according to any preceding Example, wherein the second switching circuitry arrangement comprises a Field Effect

Transistor.

Example Ex99. An aerosol-generating device according to any preceding Example, wherein the second switching circuitry arrangement comprises a MOSFET.

Example Ex100. An aerosol-generating system comprising: an aerosol-generating device according to any preceding Example; and an aerosol-generating article comprising an aerosol-forming substrate, wherein the aerosol-generating article is received in a chamber of the aerosolgenerating device.

Example Ex101. An aerosol-generating system according to Example Ex100, wherein the aerosol-generating article comprises at least one susceptor.

Example Ex102. An aerosol-generating system according to Example Ex101 , wherein the aerosol-forming substrate comprises the at least one susceptor. Example Ex103. An aerosol-generating system according to Example Ex100 or Ex101 , wherein the at least one susceptor is in the form of elongated particles.

Example Ex104. An aerosol-generating system according to Example Ex103, wherein the elongated particles are aligned with a longitudinal direction of the aerosolgenerating article.

Example Ex105. An aerosol-generating system according to Example Ex103 or Ex104, wherein the elongated particles are aligned with a longitudinal direction of the aerosol-forming substrate.

Example Ex106. An aerosol-generating system according to Example Ex100 or Ex101 , wherein the at least one susceptor is in the form of one or more strips of susceptor material.

Example Ex107. An aerosol-generating system according to Example Ex106, wherein the aerosol-generating article comprises one or more strips of aerosol-forming substrate laminated with one on more strips of susceptor material.

Example Ex108. An aerosol-generating system according to Example Ex100, wherein the aerosol-generating device comprises at least one susceptor.

Example Ex109. An aerosol-generating system according to Example Ex108, wherein the at least one susceptor is configured to be inserted into the aerosol-generating substrate when the aerosol-generating article is received in the chamber.

Example Ex1 10. An aerosol-generating system according to any one of Examples Ex100 to Ex109 wherein the aerosol-forming substrate comprises tobacco material.

Example Ex1 11 . An aerosol-generating system according to any one of Examples Ex100 to Ex11 1 , wherein the aerosol-generating article is configured to be directly inhaled upon by a user during use.

Example Ex1 12. A method of controlling an aerosol-generating system to generate an aerosol from an aerosol-generating article, the aerosol-generating system comprising: an aerosol-generating device, the aerosol-generating device comprising; a first heating arrangement and a second heating arrangement configured for heating the aerosol-generating article when in use, the first heating arrangement and the second heating arrangement electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively; a power supply system configured to supply power to the first heating arrangement and the second heating arrangement, and a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively, the aerosol-generating system further comprising an aerosol-generating article comprising an aerosol-forming substrate, wherein the aerosol-generating article is received in a chamber of the aerosol generating device, wherein the method comprises the steps of: controlling the supply of power from the power supply system to the first heating arrangement via the first switching circuitry arrangement to heat the aerosolgenerating article, and controlling the supply of power from the at least one power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article.

Example Ex1 13. A method of controlling an aerosol-generating system according to Example Ex112, wherein the power supply system includes a first power supply configured to supply power to the first heating arrangement and the second heating arrangement, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively, and wherein the method comprises the steps of: the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article, and the first control unit controlling the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article.

Example Ex1 14. A method of controlling an aerosol-generating system according to Example Ex113, wherein the method further comprises the first switching circuitry arrangement providing a first feedback signal to the first control unit, and the second switching circuitry arrangement providing a second feedback signal to the first control unit.

Example Ex1 15. An aerosol-generating device according to Example Ex1 14, wherein the method further comprises the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and controlling the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal. Example Ex1 16. An aerosol-generating device according to any one of Examples Ex113 to Ex115, wherein the method further comprises the step of the first power supply supplying power to the first control unit.

Example Ex1 17. A method of controlling an aerosol-generating system according to Example Ex112, wherein the power supply system includes a first power supply configured to supply power to the first heating arrangement and the second heating arrangement, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and includes a second control unit configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement, and wherein the method comprises the steps of: the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article, and the second control unit controlling the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article.

Example Ex1 18. A method of controlling an aerosol-generating system according to Example Ex117, wherein the method further comprises the first switching circuitry arrangement providing a first feedback signal to the first control unit, and the second switching circuitry arrangement providing a second feedback signal to the second control unit.

Example Ex1 19. A method of controlling an aerosol-generating system according to Example Ex1 18, wherein the method further comprises the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and the second control unit controlling the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal.

Example Ex120. A method of controlling an aerosol-generating system according to any one of Examples Ex1 17 to Ex119, wherein the method further comprises the first control unit providing a control signal to the second control unit, and the second control unit controlling the supply of power from the first power supply to the second heating arrangement dependent on the control signal.

Example Ex121. A method of controlling an aerosol-generating system according to Example Ex120, wherein the method further comprises the second control unit controlling the second switching circuitry arrangement to prevent the supply of power from the first power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement.

Example Ex122. A method of controlling an aerosol-generating system according to any one of Examples Ex117 to Ex1 19, wherein the method further comprises the second control unit providing a control signal to the first control unit, and the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

Example Ex123. A method of controlling an aerosol-generating system according to Example Ex122, wherein the method further comprises the first control unit controlling the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the first power supply to the second heating arrangement.

Example Ex124. A method of controlling an aerosol-generating system according to any one of Example Ex117 to Ex123, wherein the method further comprises the first power supply supplying power to the first control unit and the second control unit.

Example Ex125. A method of controlling an aerosol-generating system according to Example Ex112, wherein the power supply system comprises a first power supply configured to supply power to the first heating arrangement, and a second power supply configured to supply power to the second heating arrangement, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement, and wherein the method comprises the steps of: the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article, and the first control unit controlling the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article.

Example Ex126. A method of controlling an aerosol-generating system according to Example Ex125, wherein the method further comprises the first switching circuitry arrangement providing a first feedback signal to the first control unit, and the second switching circuitry arrangement providing a second feedback signal to the first control unit.

Example Ex127. A method of controlling an aerosol-generating system according to

Example Ex126, wherein the method further comprises the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and controlling the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

Example Ex128. A method of controlling an aerosol-generating system according to any one of Examples Ex125 to Ex127, wherein the method further comprises one of the first power supply and the second power supply supplying power to the first control unit.

Example Ex129. A method of controlling an aerosol-generating system according to Example Ex112, wherein the power supply system comprises a first power supply configured to supply power to the first heating arrangement, and a second power supply configured to supply power to the second heating arrangement, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and includes a second control unit configured to control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement, wherein the method comprises the steps of: the first control unit controlling the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement to heat the aerosol-generating article, and the second control unit controlling the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement to heat the aerosol-generating article.

Example Ex130. A method of controlling an aerosol-generating system according to Example Ex129, wherein the method further comprises the first switching circuitry arrangement providing a first feedback signal to the first control unit, and the second switching circuitry arrangement providing a second feedback signal to the second control unit.

Example Ex131. A method of controlling an aerosol-generating system according to Example Ex130, wherein the method further comprises the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and the second control unit controlling the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

Example Ex132. A method of controlling an aerosol-generating system according to any one of Examples Ex129 to Ex130, wherein the method further comprises the first control unit providing a control signal to the second control unit, and the second control unit controlling the supply of power from the second power supply to the second heating arrangement dependent on the control signal.

Example Ex133. A method of controlling an aerosol-generating system according to Example Ex132, wherein the method further comprises the second control unit controlling the second switching circuitry arrangement to prevent the supply of power from the second power supply to the second heating arrangement when power is supplied from the first power supply to the first heating arrangement.

Example Ex134. A method of controlling an aerosol-generating system according to any one of Examples Ex129 to Ex130, wherein the method further comprises the second control unit providing a control signal to the first control unit, and the first control unit controlling the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

Example Ex135. A method of controlling an aerosol-generating system according to Example Ex134, wherein the method further comprises the first control unit controlling the first switching circuitry arrangement to prevent the supply of power from the first power supply to the first heating arrangement when power is supplied from the second power supply to the second heating arrangement.

Example Ex136. A method of controlling an aerosol-generating system according to any one of Examples Ex129 to Ex135, wherein the method further comprises the first power supply supplying power to the first control unit, and the second power supply supplying power to the second control unit.

Example Ex137. A method of controlling an aerosol-generating system according to any one of Examples Ex129 to Ex135, wherein the method further comprises the second power supply supplying power to the first control unit, and the first power supply supplying power to the second control unit.

Example Ex138. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex137, wherein the method further comprises the control system preventing the supply of power to the second heating arrangement when power is supplied to the first heating arrangement.

Example Ex139. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex138, wherein the method further comprises the control system preventing the supply of power to the first heating arrangement when power is supplied to the second heating arrangement.

Example Ex140. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex139, wherein the method further comprises the control system preventing simultaneous supply of power to the first heating arrangement and the second heating arrangement.

Example Ex141. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex140, wherein the method further comprises the control system supplying power to the first heating arrangement and the second heating arrangement in an alternating fashion.

Example Ex142. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex141 , wherein the method further comprises the control system is supplying power to one of the first heating arrangement and the second heating arrangement for a first time period, and supplying power to the other of the first heating arrangement and the second heating arrangement for a second time period that does not overlap with the first time period.

Example Ex143. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex142, wherein the method further comprises the first heating arrangement generating heat from an internal location within the chamber.

Example Ex144. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex143, wherein the method further comprises the first heating arrangement heating the aerosol-generating article from an internal location within the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber.

Example Ex145. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex144, wherein the method further comprises the first heating arrangement heating the aerosol-generating article from an internal location within an aerosol-forming substrate of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber.

Example Ex146. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex145, wherein the first heating arrangement comprises an internal resistive heating element.

Example Ex147. A method of controlling an aerosol-generating system according to Example Ex146, wherein the method further comprises the control system heating the internal resistive heating element to a temperature of at least 80°C.

Example Ex148. A method of controlling an aerosol-generating system according to Example Ex146 or Ex147, wherein the method further comprises the control system heating the internal resistive heating element to a temperature of no more than 400°C.

Example Ex149. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex145, wherein the first heating arrangement comprises an inductor element, and wherein the method further comprises the inductor element inductively heating at least one internal susceptor element.

Example Ex150. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex145, wherein the first heating arrangement comprises a dielectric heater, and wherein the method further comprises the dielectric heater dielectrically heating the aerosol-forming substrate.

Example Ex151. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex150, wherein the method further comprises the second heating arrangement generating heat from an external location outside of the chamber.

Example Ex152. A method of controlling an aerosol-generating system according to any one of Examples Ex112 to Ex151 , wherein the method further comprises the second heating arrangement heating the aerosol-generating article from an external location outside of the aerosol-generating article when at least a portion of the aerosol-generating article is received within the chamber.

Example Ex153. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex152, wherein the second heating arrangement comprises an external resistive heating element.

Example Ex154. A method of controlling an aerosol-generating system according to Example Ex153, wherein the method further comprises the control system heating the external resistive heating element to a temperature of at least 80°C.

Example Ex155. A method of controlling an aerosol-generating system according to Example Ex153 or Ex154, wherein the method further comprises the control system heating the external resistive heating element to a temperature of no more than 400°C.

Example Ex156. A method of controlling an aerosol-generating system according to any one of Examples Ex1 12 to Ex145, wherein the first heating arrangement comprises an internal resistive heating element or a dielectric heater, wherein the second heating arrangement comprises an inductor element, wherein the aerosolgenerating device comprises at least one external susceptor element, and wherein the method further comprises the inductor element inductively heating the at least one external susceptor element.

The invention is further described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a side cross-section of a first embodiment of an aerosol-generating device according to the present disclosure; Figure 2 shows an axial cross-section through section A-A of the first embodiment of an aerosol-generating device according to the present disclosure;

Figure 3 shows a side cross-section of a first embodiment of an aerosol-generating system according to the present disclosure;

Figure 4 shows an axial cross-section of a second embodiment of an aerosolgenerating device according to the present disclosure;

Figure 5 shows a side cross-section of a third embodiment of an aerosol-generating device according to the present disclosure;

Figure 6 shows a side cross-section of a fourth embodiment of an aerosol-generating device according to the present disclosure;

Figure 7 shows a side cross-section of a fifth embodiment of an aerosol-generating device according to the present disclosure;

Figure 8 shows a side cross-section of a sixth embodiment of an aerosol-generating device according to the present disclosure;

Figure 9 shows a side cross-section of a second embodiment of an aerosolgenerating system according to the present disclosure, the aerosol-generating system comprising the sixth embodiment of the aerosol-generating device;

Figure 10 shows a side cross-section of a seventh embodiment of an aerosolgenerating device according to the present disclosure;

Figure 1 1 shows a side cross-section of an eighth embodiment of an aerosolgenerating device according to the present disclosure;

Figure 12 shows a schematic diagram of an oscillation circuit for use in the sixth embodiment of an aerosol-generating device;

Figure 13 shows a further schematic illustration of the oscillation circuit showing two different phase-shifting elements, one exemplarily implemented as a resonance circuit, one exemplarily implemented as a capacitive element, to achieve a 180 degrees phase shift;

Figure 14 shows a side cross-section of a ninth embodiment of an aerosol-generating device according to the present disclosure;

Figure 15 shows an axial cross-section of a tenth embodiment of an aerosolgenerating device according to the present disclosure;

Figure 16 shows a side cross-section of an eleventh embodiment of an aerosolgenerating device according to the present disclosure;

Figure 17 shows a side cross-section of a twelfth embodiment of an aerosolgenerating device according to the present disclosure;

Figure 18 shows a side cross-section of a thirteenth embodiment of an aerosolgenerating device according to the present disclosure; Figure 19 shows a side cross-section of a fourteenth embodiment of an aerosolgenerating device according to the present disclosure;

Figure 20 shows an axial cross-section of a fifteenth embodiment of an aerosolgenerating device according to the present disclosure;

Figure 21 shows a schematic diagram of an inductive heating element for use in the fifteenth embodiment of an aerosol-generating device according to the present disclosure;

Figure 22 shows a schematic diagram of control circuitry for use in any of the first to fifteenth embodiments of an aerosol-generating device according to the present disclosure;

Figures 23 to 25 show schematic diagrams of alternative control circuitry for use in any of the first to fifteenth embodiments of an aerosol-generating device according to the present disclosure;

Figure 26 shows a scheme of first and second switching signals to control the power supplied to the first heating arrangement and the second heating arrangement;

Figure 27 shows the resultant DC currents supplied to the first heating arrangement and the second heating arrangement resulting from the switching voltages illustrated in Figure 26 when implemented in an aerosol-generating device according to the first embodiment; and

Figure 28 shows a scheme of first and second switching signals and a control signal to control the power supplied to the first heating arrangement and the second heating arrangement.

Figures 1 and 2 show an aerosol-generating device 100 in accordance with a first embodiment. Figure 1 shows a side cross-sectional view of the aerosol-generating device 100. Figure 2 shows an axial cross-sectional view of the aerosol-generating device 100 of Figure 1 through section A-A.

The aerosol-generating device 100 comprises a housing 12 defining a chamber 16 for receiving a portion of an aerosol-generating article. The chamber 16 comprises an open end 18 through which an aerosol-generating article may be inserted into the chamber 16 and a closed end 20 opposite the open end 18. A cylindrical wall 22 of the chamber 16 extends between the open end 18 and the closed end 20.

The cylindrical wall 22 of the chamber 16 is at least partially defined by an inner surface of a resistive heating sleeve 160 which is received in the housing 12. The resistive heating sleeve 160 is substantially cylindrical in shape and comprises a circular cross section. The resistive heating sleeve 160 is hollow, and is open at a distal end and a proximal end of the resistive heating sleeve 160. The resistive heating sleeve 160 preferably comprises a ceramic, more preferably alumina or aluminium nitrate. An inner surface of the resistive heating sleeve 160 defines a lumen 28 in which a portion of an aerosol-generating article is received when the aerosol-generating article is inserted into the chamber 16. The aerosol-generating device 100 also comprises an internal resistive heating blade 164. The internal heating blade 164 comprises a resistive heating track printed on a polyimide substrate. The polyimide substrate is secured to the internal resistive heating blade 164. The internal resistive heating blade 164 is configured to penetrate an aerosol-generating article, and in particular an aerosol-forming substrate of the aerosol-generating article, when the aerosol-generating article is inserted into the chamber 16. The internal resistive heating blade 164 may therefore heat the aerosol-forming substrate from an internal location within the aerosol-forming substrate. The internal resistive heating blade 164 may instead be a resistive heating pin, or any other shape which may penetrate an aerosol-generating article, and in particular an aerosol-forming substrate of the aerosol-generating article, when the aerosol-generating article is inserted into the chamber 16.

The aerosol-generating device 100 also comprises an external resistive heating element 144. The external resistive heating element 144 is formed of a helical coil comprising a plurality of windings 146 disposed adjacent to and surrounding the chamber 16. The plurality of windings 146 of the external resistive heating element 144 are arranged on an outer surface of the resistive heating sleeve 160. The resistive heating sleeve 160 is a thermally conductive resistive heating sleeve, such that when the external resistive heating element 144 is heated, heat is transferred from the external resistive heating element 144 to the inner surface of the resistive heating sleeve 160. Advantageously, direct contact between the resistive heating sleeve 160 and an aerosol-generating article facilitates the transfer of heat from the resistive heating sleeve 160 to the aerosol-generating article.

The external resistive heating element 144 is wound on the outer surface of the resistive heating sleeve 160 helically about a central axis 36 of the aerosol-generating device 100. The central axis 36 of the aerosol-generating device 100 is coincident with a longitudinal axis of the resistive heating sleeve 160. Alternatively, the external resistive heating element 144 may be printed on a polyimide substrate, the polyamide substrate being wrapped around the outer surface of the resistive heating sleeve 160. Together, the resistive heating sleeve 160 and the external resistive heating element 44 form a heating assembly.

The external resistive heating element 144 is formed of a single filament, the single filament comprising stainless steel. The filament of the external resistive heating element 144 has a substantially rectangular cross section perpendicular to the direction of flow of direct current through the external resistive heating element 144. The rectangular cross section of the filament of the external resistive heating element 144 is substantially constant in size and shape for substantially the entire length of the external resistive heating element 144. The rectangular cross section of the filament of the external resistive heating element 144 has a width parallel to the central axis 36 and the longitudinal axis of the resistive heating sleeve 160. The width of the cross section of the filament of the external resistive heating element 144 is between 0.1 millimetres and 5 millimetres. In this embodiment, the rectangular cross section of the filament of the external resistive heating element 144 has a thickness perpendicular to the central axis 36 and the longitudinal axis of the resistive heating sleeve 160. The thickness of the cross section of the filament of the external resistive heating element 144 is between 0.005 millimetres and 0.5 millimetres.

The resistive heating sleeve 160 further comprises a plurality of grooves or airflow channels 62 extending in a longitudinal direction along the inner surface of the resistive heating sleeve 160, as shown in Figure 2. The longitudinal direction is parallel to the central axis 36. Each airflow channel 62 is defined in the inner surface of the resistive heating sleeve 160, and extends in a straight line from a distal end of the resistive heating sleeve 160 to a proximal end of the resistive heating sleeve 160. Advantageously, the plurality of airflow channels 62 allow for air to flow from the proximal end of the resistive heating sleeve 160 to the distal end of the resistive heating sleeve 160 when a portion of an aerosol-generating article is received by the lumen 28 when the aerosol-generating article is inserted into the chamber 16.

The housing 12 also defines a plurality of protrusions 38 extending into the chamber 16 from the closed end 20 of the chamber 16. As will be further described below, the plurality of protrusions 38 function to maintain a gap between an end of an aerosol-generating article and the closed end 20 of the chamber 16 when the aerosol-generating article is fully inserted into the chamber 16. In the embodiment shown in Figures 1 and 2, the housing 12 defines three protrusions 38 spaced equidistantly about the central axis 36 of the aerosol-generating device 10. The skilled person will appreciate that the housing 12 may define more or fewer protrusions 38 and the arrangement of the protrusions 38 at the closed end 20 of the chamber 16 may be varied.

The aerosol-generating device 100 also comprises a control system 40 and a power supply system 42 connected to the internal resistive heating blade 164 and to the external resistive heating element 144. The control system 40 is configured to provide a direct electric current from the power supply system 42 to the internal resistive heating blade 164 to generate heating in the internal resistive heating blade 164 by Joule, or resistive, heating. The control system 40 is also configured to provide a direct electric current from the power supply system 42 to the external resistive heating element 144 to generate heating in the external resistive heating element 144 by Joule, or resistive, heating. The control system 40 and the power supply system 42 are described in more detail below.

Figure 3 shows a side cross-section of a first embodiment of an aerosol-generating system 1000 according to the present disclosure. The aerosol-generating system 1000 comprises the aerosol-generating device 100 according to the first embodiment and as illustrated in Figures 1 and 2, and a first embodiment of an aerosol-generating article 1002. The first embodiment of the aerosol-generating article 1002 comprises an aerosolforming substrate 1004 in the form of a tobacco plug, a first hollow acetate tube 1006, a second hollow acetate tube 1008, a mouthpiece 1010, and an outer wrapper 1012.

During use, a portion of the aerosol-generating article 1002 is inserted into the chamber 16 of the aerosol-generating device 100 so that the aerosol-forming substrate 1004 is positioned inside the lumen 28 defined by the resistive heating sleeve 160. The internal resistive heating blade 164 penetrates the aerosol-forming substrate 1004 during insertion of the aerosol-generating article 1002 into the chamber 16 of the aerosol-generating device 100.

The control system 40 provides a direct electric current from the power supply system 42 to the internal resistive heating blade 164 to generate heating in the internal resistive heating blade 164 by Joule, or resistive, heating, which heats a central zone of the aerosol-forming substrate 1004 to generate an aerosol. The control system 40 also provides a direct electric current from the power supply system 42 to the resistive heating element 44 to generate heating in the resistive heating element 44 by Joule, or resistive, heating. The heat from the external resistive heating element 144 travels through the resistive heating sleeve 160 to a peripheral zone of the aerosol-forming substrate 1004, which heats the peripheral zone of the aerosol-forming substrate 1004 to generate an aerosol.

Airflow through the aerosol-generating system 1000 during use is illustrated by the dashed line 1016 in Figure 3. When a user draws on the mouthpiece 1010 of the aerosolgenerating article 1002, a negative pressure is generated in the chamber 16. The negative pressure draws air into the chamber 16 via the open end 18 of the chamber. The air entering the chamber 16 then flows through the plurality of airflow channels 62 defined in the inner wall of the resistive heating sleeve 160. When the airflow reaches the closed end 20 of the chamber 16, the air enters the aerosol-generating article 1002 through the aerosol-forming substrate 1004. Airflow into the aerosol-generating article 1002 is facilitated by the gap maintained between the upstream end of the aerosol-generating article 1002 and the closed end 20 of the chamber 16 by the plurality of protrusions 38. As the airflow passes through the aerosol-forming substrate 1004, aerosol generated by heating of the aerosol-forming substrate 1004 is entrained in the airflow. The aerosol then flows along the length of the aerosol-generating article 1002 and through the mouthpiece 1010 to the user.

Figure 4 shows an axial cross-section of a second embodiment of an aerosolgenerating device 1600 according to the present disclosure. The aerosol-generating device 1600 is similar to the first embodiment of an aerosol-generating device 100 described with reference to Figures 1 and 2, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts. Rather than comprising a cylindrical chamber, the chamber 1616 is instead rectangular in cross section. The chamber 1616 of the aerosol-generating device 1600 is therefore configured to receive aerosol-generating articles similar to those illustrated in Figure 3, but comprising a corresponding rectangular cross section. The cross-section of the chamber 1616 is also elongated, and comprises a width perpendicular to the longitudinal axis of the device significantly greater than a thickness perpendicular to the longitudinal axis of the device. The aerosol-generating articles which are configured to be received in the chamber 1616 may therefore be described as substantially flat. As the chamber 1616 is rectangular in cross section, the resistive heating sleeve 1660 and the windings 1646 of the external resistive heating element are also rectangular in cross-section. The skilled person would understand that other cross sectional shapes of chamber 16 are also possible, and are applicable to any of the embodiments of aerosol-generating devices described herein. For example, the chamber 1616 may instead comprise an elliptical, a square, a rounded, or a pebble-shaped cross-section.

The resistive heating sleeve 1660 does not comprise any grove or airflow channels extending parallel to the longitudinal axis of the aerosol-generating device 1600. Rather, an airflow channel (not illustrated) is provided from an outer surface of the housing 12 directly to the closed end 20 of the chamber 1616. When an aerosol-generating article is therefore received in the chamber 1616, the resistive heating sleeve 1660 contacts the aerosolgenerating article about an entire perimeter of the aerosol-generating article. In use, air therefore does not flow into the chamber 1616 via the open end of the chamber, but rather via the airflow channel provided from the outer surface of the housing 12 directly to the closed end 20 of the chamber 1616. Again, the skilled person would understand that such an arrangement comprising an airflow channel is provided from an outer surface of the housing 12 directly to the closed end 20 of the chamber 1616 may be implemented in any of the embodiment of aerosol-generating devices as described herein.

Figure 5 shows a side cross-section of a third embodiment of an aerosol-generating device 200 according to the present disclosure. The aerosol-generating device 200 is similar to the aerosol-generating device 100 described with reference to Figures 1 and 2, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts. The aerosol-generating device 200 is configured to form an aerosol-generating system similar to that illustrated in Figure 3 when the aerosol-generating article 1002 illustrated in Figure 3 is received within the chamber 16.

Rather than comprising an external resistive heating element 144, the aerosolgenerating device 200 instead comprises an inductive heating element 224.

The inductive heating element 224 is formed of a helical coil comprising a plurality of windings 226 disposed adjacent to and surrounding the chamber 16. The inductive heating element 224 is embedded within the housing 12. The inductive heating element 224 is formed of a single filament, the single filament comprising copper. The inductive heating element 224 has a substantially rectangular cross section perpendicular to the direction of flow of alternating current through the inductive heating element 224. The rectangular cross section of the inductive heating element 224 is substantially constant in size and shape for substantially the entire length of the inductive heating element 224. In this embodiment, the cross section of filament of the inductive heating element 224 has a width parallel to the central axis 36. The width of the cross section of the filament of the inductive heating element 224 is between 1 millimetre and 3 millimetres. In this embodiment, the cross section of the filament of the inductive heating element 224 has a thickness perpendicular to the central axis 36. The thickness of the cross section of the filament of the inductive heating element 224 is between 0.05 millimetres and 0.2 millimetres.

Rather than a resistive heating sleeve 160, the aerosol-generating device 200 instead comprises a susceptor sleeve 261 . The susceptor sleeve 261 comprises a susceptor material configured to be inductively heated by the inductive heating element 224.

The control system 40 is configured to provide an alternating electric current from the power supply system 42 to the inductive heating element 224 to generate an alternating magnetic field that inductively heats the susceptor sleeve 261 . The susceptor sleeve 261 is configured to heat a peripheral zone of the aerosol-forming substrate 1004 to generate an aerosol when an aerosol-generating article is received within the chamber 16.

The susceptor sleeve 261 illustrated in Figure 5 comprises the same form and shape as the resistive heating sleeve 160 of Figures 1 and 2, such that the susceptor sleeve 261 comprises a plurality of grooves or airflow channels 62 extending in a longitudinal direction along the inner surface of the susceptor sleeve 261 , as shown in Figure 2. Similarly to that described above, the plurality of airflow channels 62 allow for air to flow from the proximal end of the susceptor sleeve 261 to a distal end of the susceptor sleeve 261 when a portion of an aerosol-generating article is received by the lumen 28 when the aerosol-generating article is inserted into the chamber 16.

Figure 6 shows a side cross-section of a fourth embodiment of an aerosol-generating device according to the present disclosure. The aerosol-generating device 300 is similar to the aerosol-generating device 100 described with reference to Figures 1 and 2, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts. The aerosol-generating device 300 is configured to form an aerosol-generating system similar to that illustrated in Figure 3 when the aerosol-generating article 1002 illustrated in Figure 3 is received within the chamber 16. Rather than comprising an internal resistive heating blade 164, the aerosolgenerating device 300 instead comprises an internal susceptor blade 364, and an inductive heating element 324 configured to inductively heat the internal susceptor blade 364.

The inductive heating element 324 is formed of a helical coil comprising a plurality of windings 326 disposed adjacent to and surrounding the chamber 16. The inductive heating element 324 is embedded within the housing 12. The inductive heating element 324 is formed of a helical coil comprising a plurality of windings 326 disposed adjacent to and surrounding the chamber 16. The inductive heating element 324 is embedded within the housing 12. The inductive heating element 324 is formed of a single filament, the single filament comprising copper. The filament of the inductive heating element 324 has a substantially rectangular cross section perpendicular to the direction of flow of alternating current through the inductive heating element 324. The rectangular cross section of the filament of the inductive heating element 324 is substantially constant in size and shape for substantially the entire length of the inductive heating element 324. In this embodiment, the cross section of the inductive heating element 324 has a width parallel to the central axis 36. The width of the cross section of the filament of the inductive heating element 324 is between 1 millimetre and 3 millimetres. In this embodiment, the cross section of the filament of the inductive heating element 324 has a thickness perpendicular to the central axis 36. The thickness of the cross section of the filament of the inductive heating element 324 is between 0.05 millimetres and 0.2 millimetres.

The internal susceptor blade 364 comprises a susceptor material, and is configured to be inductively heated by the inductive heating element 324. The internal susceptor blade 364 is configured to penetrate an aerosol-generating article, and in particular an aerosolforming substrate of the aerosol-generating article, when the aerosol-generating article is inserted into the chamber 16. The internal susceptor blade 364 may therefore heat the aerosol-forming substrate from an internal location within the aerosol-forming substrate. The skilled person would understand that the internal susceptor blade 364 may instead be a resistive heating pin, or any other shape which may penetrate an aerosol-generating article, and in particular an aerosol-forming substrate of the aerosol-generating article, when the aerosol-generating article is inserted into the chamber 16.

The control system 40 is configured to provide an alternating electric current from the power supply system 42 to the inductive heating element 324 to generate an alternating magnetic field that inductively heats the internal susceptor blade 364. The internal susceptor blade 364 is configured to heat a central zone of the aerosol-forming substrate 1004 to generate an aerosol when an aerosol-generating article 1002 is received within the chamber 16. Figure 7 shows a side cross-section of a fifth embodiment of an aerosol-generating device 400 according to the present disclosure. The aerosol-generating device 400 is similar to the aerosol-generating device 300 described with reference to Figure 6, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than the aerosol-generating device comprising an external resistive heating element and an inductive heating element, the aerosol-generating device 400 instead comprises a combined resistive and inductive heating element 424.

The combined resistive and inductive heating element 424 is formed of a helical coil comprising a plurality of windings 426 disposed adjacent to and surrounding the chamber 16. In particular, the combined resistive and inductive heating element 424 is positioned on an outer surface of an external heating sleeve 460.

Similar to the inductive heating element 324 described above, the combined resistive and inductive heating element 424 is formed of a single filament, the single filament comprising copper and having a substantially rectangular cross section perpendicular to the direction of flow of alternating current through the combined resistive and inductive heating element 424. The rectangular cross section of the filament of the combined inductive and resistive heating element 424 is substantially constant in size and shape for substantially the entire length of the combined inductive and resistive heating element 424. The rectangular cross section of the filament of the combined inductive and resistive heating element 424 has a width parallel to the central axis 36 and the longitudinal axis of the external heating sleeve 460. The width of the cross section of the filament of the combined inductive and resistive heating element 424 is between 0.1 millimetres and 5 millimetres. In this embodiment, the rectangular cross section of the filament of the combined inductive and resistive heating element 424 has a thickness perpendicular to the central axis 36 and the longitudinal axis of the resistive heating sleeve 460. The thickness of the cross section of the filament of the combined inductive and resistive heating element 424 is between 0.005 millimetres and 0.5 millimetres.

In this embodiment, the combined inductive and resistive heating element 424 forms both the first heating arrangement and the second heating arrangement according to the present disclosure. This is because the combined inductive and resistive heating element 424 performs two separate heating functions, as described below.

The aerosol-generating device 400 according to the fifth embodiment is configured to generate an aerosol from the second embodiment of the aerosol-generating article 1002 as illustrated in Figure 3, when the aerosol-generating article 1002 is received within the chamber 16. The control system 40 is configured to provide an alternating electric current from the power supply system 42 to the combined inductive and resistive heating element 424 to generate an alternating magnetic field that inductively heats the internal susceptor blade 364. The internal susceptor blade 364 is configured to heat a central zone of the aerosol-forming substrate 1004 to generate an aerosol when an aerosol-generating article 1002 is received within the chamber 16.

The control system 40 is further configured to provide a direct electric current from the power supply system 42 to the combined inductive and resistive heating element 424 to generate heat in the combined inductive and resistive heating element 424 by Joule, or resistive, heating. In use, the heat from the combined inductive and resistive heating element 424 travels through the external heating sleeve 460 to a peripheral zone of the aerosolforming substrate 1004, which heats the peripheral zone of the aerosol-forming substrate 1004 to generate an aerosol.

Alternatively, the control system 40 can be configured to provide one or more alternating electric currents from the power supply system 42 to the combined inductive and resistive heating element 424 to both generate an alternating magnetic field that inductively heats the internal susceptor blade 364, and generate heat in the combined inductive and resistive heating element 424 by Joule, or resistive, heating. The frequency and the amplitude of the one or more alternating electric currents affects the amount of power supplied from the combined inductive and resistive heating element 424 to the internal susceptor blade 364, as well as the amount of heat generated in the combined inductive and resistive heating element 424 by Joule, or resistive, heating. The control system 40 may therefore vary or adjust the frequency or amplitude of the one or more alternating electric currents supplied to the combined inductive and resistive heating element 424 to provide more or less power to the internal susceptor blade 364, or to generate more or less heat in the combined inductive and resistive heating element 424 by Joule, or resistive, heating.

Figure 8 shows a side cross-section of a sixth embodiment of an aerosol-generating device according to the present disclosure. The aerosol-generating device 500 is similar to the aerosol-generating device 300 described with reference to Figure 6, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than the aerosol-generating device comprising an internal susceptor blade 364, the aerosol-generating device 500 instead does not comprise an internal susceptor blade 364. Rather, the inductive heating element 324 is configured to inductively heat an internal susceptor element 464 located within an aerosol-generating article 4002, as described below with respect to Figure 9. Figure 9 shows a side cross-section of a second embodiment of an aerosolgenerating system 5000 according to the present disclosure. The aerosol-generating system 1000 comprises the aerosol-generating device 500 according to the sixth embodiment and as illustrated in Figure 8, and a second embodiment of an aerosol-generating article 5002.

The second embodiment of the aerosol-generating article 5002 is substantially identical to the first embodiment of the aerosol-generating article 1002 illustrated in Figure 3, except that the second embodiment of the aerosol-generating article 5002 comprises an internal susceptor element 564 located within the aerosol-forming substrate 1004. The internal susceptor element 564 is illustrated as a singular rod of susceptor material. However, the skilled person would understand that the internal susceptor element 564 may be comprised of one or more rods, beads, particles, elongated particle, strips, or ribbons of susceptor material.

The control system 40 is configured to provide an alternating electric current from the power supply system 42 to the inductive heating element 324 to generate an alternating magnetic field that inductively heats the internal susceptor element 564. The internal susceptor element 564 is configured to heat a central zone of the aerosol-forming substrate 1004 to generate an aerosol when an aerosol-generating article 5002 is received within the chamber 16.

Figure 10 shows a side cross-section of a seventh embodiment of an aerosolgenerating device 600 according to the present disclosure.

The aerosol-generating device 600 is similar to the aerosol-generating device 400 described with reference to Figure 7, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than the aerosol-generating device 600 comprising an internal susceptor blade 364, the aerosol-generating device 600 instead does not comprise an internal susceptor blade 364. Rather, the aerosol-generating device 600 is configured to receive in the chamber 16 an aerosol-generating article 5002 comprising an internal susceptor element 564, similar to that described above in Figure 9. The combined resistive and inductive heating element 424 is therefore configured to inductively heat an internal susceptor element 564 located within an aerosol-generating article 5002, rather than an internal susceptor blade.

Figure 11 shows a side cross-section of an eighth embodiment of an aerosolgenerating device 700 according to the present disclosure. The aerosol-generating device 700 is similar to the aerosol-generating device 100 described with reference to Figures 1 and 2, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than comprising an internal resistive heating blade 164, the aerosolgenerating device 700 instead comprises first and second electrodes 750 forming a load capacitor. The first and second electrodes 750 are positioned on opposite inside surfaces of the chamber 16, and are located within the lumen 28 defined by the resistive heating sleeve 160. The first and second electrodes 750 each comprise a metallic plate made of stainless steel, for example, and extend the majority of the longitudinal length of the chamber 16. The first and second electrodes 750 are therefore also curved in order to conform to the inner surfaces of the chamber 16. The skilled person would understand however that the first and second electrodes 750 may be flat and planar when the chamber 16 comprises a rectangular cross-section for example.

The first and second electrodes 750 form a dielectric heater, configured to dielectrically heat the aerosol-forming substrate 1004 when the aerosol-generating article 1002 is received within the chamber. The operation of the dielectric heating using the first and second electrodes 750 is described below.

The eighth embodiment of an aerosol-generating device 700 is configured for use with the first embodiment of the aerosol-generating article 1002 as illustrated in Figure 3. In other words, the eighth embodiment of an aerosol-generating device 700 does not require the aerosol-generating article 1002 to comprise an internal susceptor element.

The resistive heating sleeve 760 does not comprise any grove or airflow channels extending parallel to the longitudinal axis of the aerosol-generating device 700. Rather, an airflow channel (not illustrated) is provided from an outer surface of the housing 12 directly to the closed end 20 of the chamber 16. When an aerosol-generating article is therefore received in the chamber 16, the first and second electrodes 750 and the resistive heating sleeve 760 together contact the aerosol-generating article about an entire perimeter of the aerosol-generating article. In use, air therefore does not flow into the chamber 16 via the open end 18 of the chamber 16, but rather via the airflow channel provided from the outer surface of the housing 12 directly to the closed end 20 of the chamber 16, as is described above with respect to the second embodiment of the aerosol-generating device.

Figure 12 is a schematic diagram of an oscillation circuit 850 for use in the eighth embodiment of an aerosol-generating device 700. The oscillation circuit 850 forms one of the heaters of the aerosol-generating device 700. The oscillation circuit 850 comprises a switching unit 860 interconnected with a resonator feedback loop 870 to provide for a selfoscillating signal to the switching unit 860. The switching unit 860 comprises a single transistor, such as a bipolar junction transistor (BJT) or a field effect transistor (FET).

The oscillation circuit 850 can further comprise a choke 880 that acts on an input to the feedback loop 870 to provide for a stimulation signal, for example a stimulation voltage. The oscillation circuit also comprises a biasing unit 890 acting on the feedback loop 870 for providing a variable or controllable biasing signal, for example a biasing voltage for setting the operating conditions. In the variant shown, the feedback signal can be described as a voltage. The output voltage UOUT of the switching unit 860 is coupled to the feedback loop 870 providing a feedback switching signal in the form of a voltage UIN to the switching unit 860. The configuration of the feedback loop 870 is such that the output signal, e.g. the voltage UOUT of the switching unit 860 can undergo a phase change and arrives inverted at the input UIN of the switching unit 860 for resonant oscillation. In other configurations, a current could be used as the feedback signal with a switching unit 860 comprising a BJT.

The feedback loop 870 is configured to be self-oscillating and will oscillate at or close to a given resonance frequency determined by the values of the passive components of the feedback loop 870. Feedback loop 870 is configured to provide a 180° phase shift from the output UOUT to input UIN of switching unit 860 for oscillation, and in addition, the transistor T is configured for inverting operation. In this embodiment, the dielectric heater as described herein consists of the oscillation circuit 850.

As shown in Figure 13, feedback loop 870 includes a resonant circuit 872 comprising the load capacitor CL providing for a first 90 degrees phase shift or quarter wave shift to the feedback signal. Feedback loop 870 further includes a capacitive element 874 providing for a second 90 degrees phase shift or quarter wave shift to the feedback signal, such that the feedback signal reaching the input of the switching unit 860 is inverted and phase-shifted by 180 degrees. Switching unit 860 is itself configured for inverted switching operation to provide a 180 degree phase shift between the input UIN and the output UOUT of the switching unit 860.

Resonant circuit 872 comprises the first and second electrodes 750, together forming a load capacitor CL. When an aerosol-forming substrate 1004 is situated between the first and second electrodes 750, it forms part of the load capacitor CL. Importantly, the load capacitor CL is formed in the feedback loop 870, and not at a separate output or part of a separate circuitry that is connected to the switching unit 860. This enables a high-frequency oscillating voltage to be created across the electrodes of load capacitor CL, which is needed for sufficient and efficient dielectric heating of the aerosol-forming substrate 1004, without having an additional output or circuit to the already resonating feedback loop 870, which would create unnecessary losses and circuit complexity. The resonant circuit 872 may comprise a series resonator circuit or a parallel resonator circuit. In this embodiment, the dielectric heater as described herein consists of the oscillation circuit 850.

Figure 14 shows a side cross-section of a ninth embodiment of an aerosol-generating device 900 according to the present disclosure.

The aerosol-generating device 900 is similar to the aerosol-generating device 700 described with reference to Figure 1 1 , so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts. Rather than the first and second electrodes being located within the lumen 28 defined by a resistive heating sleeve, the first and second electrodes 950 are instead positioned in a distal half of the chamber 16. The resistive heating sleeve 960 is therefore positioned in a proximal half of the chamber 16. The external resistive heater 944 surrounds the resistive heating sleeve 960 and the proximal half of the chamber 16 with a plurality of windings 946. In this embodiment, when an aerosol-generating article is received within the chamber 16, the first and second electrodes 950 are configured to heat a distal half of the aerosol-forming substrate within the aerosol-generating article, and the external resistive heater 944 is configured to heat a proximal half of the aerosol-forming substrate within the aerosolgenerating article.

Figure 15 shows an axial cross-section of a tenth embodiment of an aerosolgenerating device 900 according to the present disclosure.

The aerosol-generating device 1 100 is similar to the aerosol-generating device 700 described with reference to Figure 1 1 , so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than the first and second electrodes being located within the lumen 28 defined by a resistive heating sleeve, the first and second electrodes 1 150 are instead positioned along an inner surface of the housing 12 to form two longitudinally extending quarter-circle portions opposite one another. Two resistive heating sleeve portions 1160 are also positioned along an inner surface of the housing 12 to form two longitudinally extending quarter-circle portions opposite one another. The chamber 16 is therefore defined by alternating quadrants of longitudinally extending resistive heating sleeve portions 1 160 and the first and second electrodes 1 150. Longitudinal grooves 1 162 are formed in the resistive heating sleeve portions 1160 similar to those described with respect to Figures 1 and 2.

External resistive heater portions 1146 are arranged on an outer surface of both resistive heating sleeve portions 1160. The external resistive heater portions 1146 may be separate heating portions, separately electrically connected to the control system 40. Alternatively, the external resistive heater portions 1 146 can be coupled heating portions, electrically connected or formed from a single filament, and together electrically connected to the control system 40. The external resistive heater portions 1146 otherwise function in an identical manner to that described with respect to Figures 1 and 2.

Figure 16 shows a side cross-section of an eleventh embodiment of an aerosolgenerating device 1200 according to the present disclosure.

The aerosol-generating device 1200 is similar to the aerosol-generating device 700 described with reference to Figure 1 1 , so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts. Rather than comprising first and second electrodes located within the lumen defined by the resistive heating sleeve, the device comprises first and second electrodes 1250 positioned on internal walls of the cavity 16 formed in the housing 12 of the aerosolgenerating device 1200. The aerosol-generating device 1200 does not comprise a resistive heating sleeve or an external resistive heater.

Instead, the control system 40 is configured to supply a direct electrical current to one or both of the first and second electrodes 1250, in addition to the oscillating voltage supplied across the first and second electrodes 1250 as outlined above with respect to Figures 12and 13. The control system 40 is therefore also configured to generate heat in one or both of the first and second electrodes 1250 by Joule, or resistive, heating. One or both of the first and second electrodes 1250 are therefore configured to externally heat an aerosol-generating article when an aerosol-generating article is received within the chamber.

Alternatively or additionally, the control system 40 is configured to generate heat in one or both of the first and second electrodes 1250 by Joule, or resistive, heating as a result of the oscillating voltage supplied across the first and second electrodes 1250 as outlined above with respect to Figures 12 and 13. The dimensions of the first and second electrodes 1250 may be selected to tune the amount of heat generated by resistive heating in one or both of the first and second electrodes 1250 when the oscillating voltage is supplied across the first and second electrodes 1250. The oscillating circuit 850 may vary the frequency of the oscillating voltage supplied across the first and second electrodes 1250 in order to adjust the amount of resistive heating in one or both of the first and second electrodes 1250.

Figure 17 shows a side cross-section of a twelfth embodiment of an aerosolgenerating device according to the present disclosure.

The aerosol-generating device 1300 is similar to the aerosol-generating device 700 described with reference to Figure 1 1 , so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

The twelfth embodiment of an aerosol-generating device 1300 is configured for use with an aerosol-generating article 5002 as illustrated in Figure 9.

Rather than comprising a resistive heating sleeve 160 and an external resistive heating element 144 wound on the outer surface of the resistive heating sleeve 160, the aerosol-generating device 1300 instead comprises an inductive heating element 1324 configured to inductively heat an internal susceptor element 564 located within an aerosolgenerating article 5002, as described above with respect to Figure 9. The first and second electrodes 950 are therefore arranged on an inner wall of the chamber 16 formed by the housing 12. The inductive heating element 1324 comprises a helical coil comprising a plurality of windings 1326 embedded within the housing 12, and is substantially identical to that described above with respect to Figure 5.

The control system 40 is configured to provide an alternating electric current from the power supply system 42 to the inductive heating element 1324 to generate an alternating magnetic field that inductively heats the internal susceptor element 564. The internal susceptor element 564 is configured to heat a central or peripheral zone of the aerosolforming substrate 1004 to generate an aerosol when an aerosol-generating article 5002 is received within the chamber 16, depending on the location of the internal susceptor element 564 within the aerosol-forming substrate 1004.

Figure 18 shows a side cross-section of a thirteenth embodiment of an aerosolgenerating device according to the present disclosure.

The aerosol-generating device 1400 is similar to the aerosol-generating device 1300 described with reference to Figure 17, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than first and second electrodes extending most of the longitudinal length of the chamber 16, the first and second electrodes 1450 are instead positioned in a distal half of the chamber 16. The inductive heating element 1424 comprising a plurality of windings 1426 is therefore positioned around a proximal half of the chamber 16. The inductive heating element 1424 comprising a plurality of windings 1426 surrounds the proximal half of the chamber 16.

In this embodiment, when an aerosol-generating article is received within the chamber 16, the first and second electrodes 1450 are configured to heat a distal half of the aerosol-forming substrate within the aerosol-generating article through dielectric heating, and the inductive heating element 1424 is configured to inductively heat an internal susceptor element 564 within a proximal half of the aerosol-forming substrate 1004.

Figure 19 shows a side cross-section of a fourteenth embodiment of an aerosolgenerating device according to the present disclosure.

The aerosol-generating device 1500 is similar to the aerosol-generating device 1300 described with reference to Figure 17, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than first and second electrodes extending most of the longitudinal length of the chamber 16, the first and second electrodes 1550 are instead positioned in a central third of the chamber 16. Two inductive heating elements 1524, each comprising a plurality of windings 1526, are therefore positioned around a proximal third of the chamber 16 and a distal third of the chamber 16 respectively. The two inductive heating elements 1524 each surround the proximal third of the chamber 16 and the distal third of the chamber 16 respectively. The two inductive heating elements 1524 may each be separately connected to the control system 40, such that the control system 40 is configured to supply an alternating current to each of the two inductive heating elements 1524 independently of one another. Alternatively, the two inductive heating elements 1524 may be electrically connected in series for example, such that the control system 40 is configured to supply the same alternating current to both of the two inductive heating elements 1524.

In this embodiment, when an aerosol-generating article is received within the chamber 16, the first and second electrodes 1550 are configured to heat a central third of the aerosol-forming substrate within the aerosol-generating article through dielectric heating, and the two inductive heating elements 1524 are configured to inductively heat an internal susceptor element 564 within a distal third and a proximal third of the aerosol-forming substrate 1004 respectively. The varying magnetic fields generated by the two inductive heating elements 1524 may be sufficiently strong to cooperate with one another, and inductively heat an internal susceptor element 564 within the entire longitudinal length of the chamber 16, and hence the entire longitudinal length of the aerosol-forming substrate 1004.

Figure 20 shows an axial cross-section of a fifteenth embodiment of an aerosolgenerating device 1700 according to the present disclosure.

The aerosol-generating device 1700 is similar to the aerosol-generating device 1300 described with reference to Figure 17, so the embodiment is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than the chamber comprising a substantially cylindrical cross-section, the chamber 1716 instead comprises a substantially square cross-section. On two diametrically opposed inner walls of the housing 1712, the first and second electrodes 1750 are located, respectively. The first and second electrodes 1750 are flat plates, rather than curved plates. The first and second electrodes 1750 along with two further diametrically opposed inner walls of the housing 1712 form the four sides of the substantially square cross-section of the chamber 1716. The chamber 1716 is therefore configured to receive an aerosol-generating article comprising a substantially square cross-section of the same of substantially similar size.

The aerosol-generating device 1700 further comprises two inductive heating elements 1724. The two inductive heating elements 1724 are each embedded within the housing 1712 and are each adjacent to one of the two further diametrically opposed inner walls of the housing 1712, respectively. The two inductive heating elements 1724 are illustrated in more detail in Figure 21. Each of the two inductive heating elements 1724 are not in the form of a helical coil, but instead as two separate and substantially identical flat and planar coiled inductor elements. Figure 21 also indicates the line B-B through which the cross-section of Figure 20 is taken. The two inductive heating elements 1724 each comprise a first end 1778 and a second end 1779. Each of the first ends 1778 and the second ends 1779 are connected via wires (not shown) to the control system 40 as described above.

The two inductive heating elements 1724 may each be separately connected to the control system 40, such that the control system 40 is configured to supply an alternating current to each of the two inductive heating elements 1724 independently of one another. Alternatively, the two inductive heating elements 1724 may be electrically connected in series for example, such that the control system 40 is configured to supply the same alternating current to both of the two inductive heating elements 1524.

In this embodiment, when an aerosol-generating article is received within the chamber 1716, the first and second electrodes 1750 are configured to heat the aerosolforming substrate within the aerosol-generating article through dielectric heating, and the two inductive heating elements 1724 are configured to inductively heat an internal susceptor element within the aerosol-forming substrate, respectively. The varying magnetic fields generated by the two inductive heating elements 1724 may be sufficiently strong to cooperate with one another, and inductively heat an internal susceptor element within an entire width perpendicular to the longitudinal length of the chamber 1716, and hence an entire width perpendicular to the longitudinal length of the aerosol-forming substrate.

Although the embodiments in Figures 17 to 21 have been described with respect to use with an aerosol-generating article 5002 comprising an internal susceptor element 564, these embodiments of an aerosol-generating device may instead or additionally comprise an internal susceptor blade or pin, as illustrated and described with respect to Figure 5, and therefore be configured to generate an aerosol from an aerosol-generating article 1002 as illustrated in Figure 3, when the aerosol-generating article 1002 is received within the chamber 16.

Figure 22 shows a schematic diagram of control circuitry for use in any of the first to fifteenth embodiments of an aerosol-generating device according to the present disclosure.

The control circuitry comprises a power supply system 42. The power supply system comprises a first DC power supply 81. The first DC power supply 81 consists of one rechargeable lithium-ion battery cell, and is for example one of a 18650 cell, a 14500 cell, or a 14650 cell that provides for 3.2V to 3.9V.

However, a voltage of one battery cell of an exemplary 3.5V to 7V for power supply can be boosted, for example by a DC-DC converter (e.g. a boost circuit), or a voltage doubler.

Alternatively or in addition, two or more battery cells can be used in series, or other configurations or arrangements that allows to increase a voltage from one or more battery cell can be used. It is also possible to have a controllable output voltage (e.g. DC-DC converter, voltage regulator), to control the temperature of heating by a change to the DC supply voltage, or to boost the voltage (for example to 10-12V) for maximum power at the preheating stage, to speed up the preheating stage with the goal to reach the aerosolization temperature quickly.

The control circuitry comprises a control system 40. The control system 40 comprises a first control unit 83. The first control unit 83 is a microprocessor. The first control unit 83 receives power from the first DC power supply 81 to power operation of the first control unit 83.

The control system 40 further comprises a first switching circuitry arrangement 85 and second switching circuitry arrangement 86. Each of the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 comprise a switch, such as a field effect transistor or a MOSFET. Each of the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 are configured to allow or prevent the supply of power from the first DC power supply 81 to a first heating arrangement 164 and a second heating arrangement 144 respectively.

The first switching circuitry arrangement 85 and second switching circuitry arrangement 86 are configured to receive a first switching signal 91 and a second switching signal 93 respectively from the first control unit 83. The first switching signal 91 and second switching signal 93 each comprise an electrical signal, such as a voltage or a current.

The first switching signal 91 and second switching signal 93 are configured to control the operation of the switches of the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 respectively. For example, when the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 each comprise a field effect transistor or a MOSFET, the first switching signal 91 and second switching signal 93 are electrically supplied to the gate terminals of the two respective field effect transistors. The first switching signal 91 and second switching signal 93 will therefore control the power from the first DC power supply 81 at a source terminal of each field effect transistor to the respective first heating arrangement 164 or second heating arrangement 144 electrically connected to a drain terminal of the respective field effect transistor.

The first control unit 83 is therefore configured to control the power supplied from the first DC power supply 81 to the first heating arrangement 164 and the second heating arrangement 144.

The first switching circuitry arrangement 85 and second switching circuitry arrangement 86 are also configured to send a first feedback signal 92 and a second feedback signal 94 respectively to the first control unit 83. The first feedback signal 92 and the second feedback signal 94 each comprise an electrical signal, such as a voltage or a current. Both the first feedback signal 92 and the second feedback signal 94 are dependent on a temperature of the first heating arrangement 164 and the second heating arrangement 144 respectively. For example, the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 determine electrical resistances of the first heating arrangement 164 and the second heating arrangement 144 respectively, which are dependent on the temperatures of the first heating arrangement 164 and the second heating arrangement 144 respectively. The first feedback signal 92 and the second feedback signal 94 then each comprise an electrical signal dependent on the electrical resistances of the first heating arrangement 164 and the second heating arrangement 144 respectively.

The first control unit 83 is then configured to adjust the first switching signal 91 and second switching signal 93 dependent on the first feedback signal 92 and the second feedback signal 94 respectively. For example, the first control unit 83 may adjust the first switching signal 91 or the second switching signal 93 such that the first switching circuitry arrangement 85 or second switching circuitry arrangement 86 respectively allows power to be supplied from the first DC power supply 81 to the first heating arrangement 164 or the second heating arrangement 144 respectively for longer time intervals. This would increase the temperatures of the first heating arrangement 164 or the second heating arrangement 144, respectively. This way, the first control unit 83 is configured to control the temperatures of the first heating arrangement 164 and the second heating arrangement 144.

In this example, the first heating arrangement 164 and the second heating arrangement 144 are both described as resistive heaters, as in Figures 1 and 2. However, the first heating arrangement 164 and the second heating arrangement 144 may be any pair of two heating arrangements as described in Figures 1 to 21. Furthermore, and with reference to Figures 7, 10 and 16, a singular heater may comprise both the first heating arrangement 164 and the second heating arrangement 144. For example, the combined resistive and inductive heating element 424 as illustrated in Figures 7 and 10 may comprise both the first heating arrangement 164 and the second heating arrangement 144 as referenced herein. Similarly, with reference to Figure 16, the oscillating circuit 850 may comprise one of the first heating arrangement 164 and the second heating arrangement 144, and the first and second electrodes 1250 of said oscillating circuit 850 may comprise the other of the first heating arrangement 164 and the second heating arrangement 144.

When one of the first heating arrangement 164 and the second heating arrangement 144 is an inductive heating element, the corresponding first switching circuitry arrangement 85 or second switching circuitry arrangement 86 comprises a DC/AC converter configured to convert a direct current supplied from the power supply system 82 to an alternating current to be supplied to the inductive heating element, in addition to switch as described above. The DC/AC can comprise a Class-E power amplifier for example. The corresponding first switching circuitry arrangement 85 or second switching circuitry arrangement 86 would therefore be configured to supply an alternating current to the inductive heating element, or prevent the supply an alternating current to the inductive heating element, depending on the state of the switch.

When one of the first heating arrangement 164 and the second heating arrangement 144 is an inductive heating element, the corresponding first feedback signal 92 or second feedback signal 94 is dependent on a temperature of a susceptor element coupled to the inductive heating element. The susceptor element may be part of the aerosol-generating device, or an aerosol-generating article, as described in detail above. For example, one of the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 is configured to determine an electrical resistance or inductance of the inductive heating element, which is dependent on the temperature of a susceptor element coupled to the inductive heating element. The corresponding first feedback signal 92 or the second feedback signal 94 then comprises an electrical signal dependent on the electrical resistance or inductance of the inductive heating element. This way, the first control unit 83 is configured to control the temperatures of the susceptor element coupled to the inductive heating element.

When one of the first heating arrangement 164 and the second heating arrangement 144 is a dielectric heater comprising the resonant circuit 872 comprising the two electrodes 750 as described above with respect to Figures 12 and 13, the corresponding first switching circuitry arrangement 85 or second switching circuitry arrangement 86 comprises the remaining parts of the oscillating circuit 850, in addition to switch as described above. The corresponding first switching circuitry arrangement 85 or second switching circuitry arrangement 86 would therefore be configured to supply an oscillating voltage across the two electrodes 750, or prevent the supply an oscillating voltage across the two electrodes 750, depending on the state of the switch.

When one of the first heating arrangement 164 and the second heating arrangement 144 is an inductive heating element, the corresponding first feedback signal 92 or second feedback signal 94 is dependent on a temperature of an aerosol-forming substrate positioned between the two electrodes 750.

For example, one of the first switching circuitry arrangement 85 and second switching circuitry arrangement 86 is configured to detect an electrical property of a component of the oscillating circuit 850, such as a current, a voltage, a resistance or an inductance of a component of the oscillating circuit 850, which is dependent on the temperature of the aerosol-forming substrate positioned between the two electrodes 750. The corresponding first feedback signal 92 or the second feedback signal 94 then comprises an electrical signal dependent on the temperature of the aerosol-forming substrate positioned between the two electrodes 750. Alternatively or additionally, the aerosol-generating device further comprises a temperature sensor configured to detect a temperature indicative of the temperature of an aerosol-forming substrate within or adjacent to the load capacitor. In an example, the temperature sensor may be a contact sensor configured to directly measure the temperature of the aerosol-forming substrate or a component in the vicinity of the aerosol-forming substrate. In another example, the temperature sensor may be a non-contact sensor configured to capture heat radiation from the aerosol-forming substrate or a component in the vicinity of the aerosol-forming substrate. In an example, the non-contact temperature sensor is configured to capture heat radiation from a component that increases or homogenizes the heat radiation and has greater thermal conductive properties than the aerosol-forming substrate. The corresponding first feedback signal 92 or the second feedback signal 94 then comprises an electrical signal dependent on the temperature measured by the temperature sensor, as so dependent on the aerosol-forming substrate positioned between the two electrodes 750.

Both of these ways allow for the first control unit 83 to control the temperature of the aerosol-forming substrate positioned between the two electrodes 750.

Figures 23 to 25 show schematic diagrams of alternative control circuitry for use in any of the first to fifteenth embodiments of an aerosol-generating device according to the present disclosure.

In Figure 23, the alternative control circuitry is similar to the control circuitry described with reference to Figure 22, so the alternative control circuitry is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than comprising a singular control unit, the control system comprises a first control unit 83 and a second control unit 84. Both the first control unit 83 and the second control unit 84 are microprocessors. Both the first control unit 83 and the second control unit 84 receive power from the first DC power supply 81 to power operation of the first control unit 83 and the second control unit 84.

The first switching circuitry arrangement 85 is configured to receive the first switching signal 91 from the first control unit 83. The second switching circuitry arrangement 86 is configured to receive the second switching signal 93 from the second control unit 84. The switching signals are substantially identical to those described above with respect to Figure 22.

The first control unit 83 is therefore configured to control the power supplied from the first DC power supply 81 to the first heating arrangement 164. The second control unit 84 is therefore configured to control the power supplied from the first DC power supply 81 to the second heating arrangement 144. The first switching circuitry arrangement 85 is configured to send the first feedback signal 92 to the first control unit 83. The second switching circuitry arrangement 86 is configured to send the second feedback signal 94 to the second control unit 84. The feedback signals are substantially identical to those described above with respect to Figure 22.

The first control unit 83 is configured to adjust the first switching signal 91 dependent on the first feedback signal 92. The second control unit 84 is configured to adjust the second switching signal 93 dependent on the second feedback signal 94.

This way, the first control unit 83 is configured to control the temperature of the first heating arrangement 164, and second control unit 84 is configured to control the temperature of the second heating arrangement 144.

The first control unit 83 is further configured to provide a control signal 97 to the second control unit 84. The control signal 97 comprises an electrical signal, such as a voltage or a current.

The control signal 97 is dependent on the first switching signal 91 sent from the first control unit 83 to the first switching circuitry arrangement 85. The second control unit 84 is configured to adjust the second switching signal 93 sent to the second switching circuitry arrangement 86 dependent on the control signal 97. The first control unit 83 may therefore act as a master control unit, and the second control unit 84 may therefore act as a slave control unit, and the operation of the two heating arrangements 164, 144 may be synchronised.

In this particular example, the second control unit 84 is configured to adjust the second switching signal 93 sent to the second switching circuitry arrangement 86 dependent on the control signal 97 such that the second switching circuitry arrangement 86 prevents power from being supplied to the second heating arrangement 144 when power is supplied to first heating arrangement 164. This operation is described in more detail below.

The hierarchy of the first control unit 83 and the second control unit 84 may be the other way round. In other words, the second control unit 84 may be configured to supply the control signal 97 to the first control unit 83. In this configuration, the first control unit 83 may therefore act as a slave control unit, and the second control unit 84 may therefore act as a master control unit.

In Figure 24, the alternative control circuitry is similar to the control circuitry described with reference to Figure 22, so the alternative control circuitry is described with respect to its differences only, and like reference numerals are used to designate like parts.

Rather than comprising a singular DC power supply, the power supply system 42 comprises a first DC power supply 81 and a second DC power supply 82. Both the first DC power supply 81 and the second DC power supply 82 each consist of one rechargeable lithium-ion battery cell, for example one of a 18650 cell, a 14500 cell, or a 14650 cell. The first DC power supply 81 and the second DC power supply 82 are however bundled together in a singular package, which may be removed or replaced as a singular unit from the aerosolgenerating device. In other words, the power supply system 42 can be removed or replaced as a singular unit from the aerosol-generating device.

In this embodiment, first control unit 83 is configured to control the supply of power from the first DC power supply 81 to the first heating arrangement 164 via the first switching circuitry arrangement 85, and control the supply of power from the second DC power supply 82 to the second heating arrangement 144 via the second switching circuitry arrangement 86. The first heating arrangement 164 and the second heating arrangement 144 are therefore supplied by different power supplies.

In this embodiment, it is the first DC power supply 81 which is configured supplied power to the first control unit 83 to enable operation of the first control unit 83. The second DC power supply 82, or both the first DC power supply 81 and the second DC power supply 82 can instead be configured to supply power to the first control unit 83 to enable operation of the first control unit 83.

In Figure 25, the alternative control circuitry is similar to the control circuitry described with reference to Figure 23, so the alternative control circuitry is described with respect to its differences only, and like reference numerals are used to designate like parts.

In this embodiment, the first control unit 83 is configured to control the supply of power from the first DC power supply 81 to the first heating arrangement 164 via the first switching circuitry arrangement 85. The second control unit 84 is configured to control the supply of power from the second DC power supply 82 to the second heating arrangement 144 via the second switching circuitry arrangement 144. The first heating arrangement 164 and the second heating arrangement 144 are therefore supplied by different power supplies.

In this embodiment, the first DC power supply 81 is configured to supply power to the first control unit 83 to enable operation of the first control unit 83, and the second DC power supply 82 is configured to supply power to the second control unit 84 to enable operation of the second control unit 84. Instead the first DC power supply 81 can be configured to supply power to the second control unit 84 to enable operation of the second control unit 84, and the second DC power supply 82 can be configured to supply power to the first control unit 83 to enable operation of the first control unit 83.

Figure 26 illustrates a scheme of the first switching signal 91 and the second switching signal 93 supplied to the first switching circuitry arrangement 85 and the second switching circuitry arrangement 86 respectively to control the power supplied to the first heating arrangement 164 and the second heating arrangement 144 respectively. The scheme illustrated in Figure 26 may be implemented in any of control circuitry embodiments illustrated in Figures 22 to 25.

The first switching signal 91 comprises a first switching voltage, has a rectangular profile, and alternates between zero volts and an ‘ON’ voltage Vsi. When the ‘ON’ voltage Vsi is supplied to the first switching circuitry arrangement 85, the first switching circuitry arrangement 85 supplies power from the first DC power supply 81 (or second DC power supply 82 depending on the power supply system 40 configuration) to the first heating arrangement 164. When zero volts are supplied to the first switching circuitry arrangement 85, the first switching circuitry arrangement 85 prevents the supply of power from the first DC power supply 81 (or second DC power supply 82 depending on the power supply system 40 configuration) to the first heating arrangement 164.

The second switching signal 93 comprises a first switching voltage, has a rectangular profile, and alternates between zero volts and an ‘ON’ voltage Vs2. When the ‘ON’ voltage Vs2 is supplied to the second switching circuitry arrangement 86, the second switching circuitry arrangement 86 supplies power from the second DC power supply 82 (or first DC power supply 81 depending on the power supply system 40 configuration) to the second heating arrangement 144. When zero volts are supplied to the second switching circuitry arrangement 86, the second switching circuitry arrangement 86 prevents the supply of power from the second DC power supply 82 (or first DC power supply 81 depending on the power supply system 40 configuration) to the second heating arrangement 144.

It has been found that preventing simultaneous supply of power to the first heat 164 and the second heating arrangement 144 is particularly beneficial. Firstly, simultaneous supply of power to the first heat 164 and the second heating arrangement 144 may overheat an aerosol-forming substrate, resulting in undesirable compounds forming which are subsequently inhaled by a user.

Furthermore, preventing simultaneous supply of power is also particularly beneficial when the power supply system 40 comprises only a first DC power supply 81 , as power supplied to two heating arrangements from only a first DC power supply 81 may draw too much current from the first DC power supply 81 , stressing the first DC power supply 81 and affecting the lifespan of the first DC power supply 81 .

Furthermore, it has been found that preventing simultaneous supply of power to the first heating arrangement 164 and the second heating arrangement 144 is particularly beneficial when one of the first or second heating arrangements comprises an inductive heating element, and the other of the first or second heating arrangements is a resistive heating element for example. When the alternating current from the first or second switching circuitry arrangements 85, 86 is supplied to the inductive heating element, the alternating magnetic field generated may induce a current in the other of the first or second heating arrangements, i.e. in the resistive heating element. This induced current may affect the respective feedback signal from the resistive heating element, which may therefore affect the ability of the corresponding control unit to control the temperature of the resistive heating element according to a pre-determined temperature profile. It has been found that by preventing simultaneous supply of power to the first heating arrangement 164 and the second heating arrangement 144 when one of the first or second heating arrangements comprises an inductive heating element, and the other of the first or second heating arrangements is a resistive heating element, any induced current in the resistive heating element does not affect the corresponding feedback signal from the resistive heating element.

To prevent this simultaneous supply, the first switching signal 91 is equal to the ‘ON’ voltage Vsi between time intervals to and ti, and t2 and ts, and is equal to zero volts between time intervals ti and t2, and ts and t4.

These four time interval are illustrative of a sequence of time intervals which are ongoing beyond t4.

The control circuitry is configured to maintain the temperature of the first heating arrangement 164 (or a temperature of a susceptor element coupled to the first heating arrangement) at a target temperature, or follow a target temperature profile, using pulsewidth modulation by adjusting the length of the time intervals to to ti, and t2 to ts, and ti to t2, and ts to t4.

The second switching signal 93 is equal to the ‘ON’ voltage Vs2 for a reduced time period between the time intervals ti and t2, and ts and t4, and is equal to zero volts between time intervals to and ti, and t2 and ts.

Therefore, in the scheme of switching voltages shown in Figure 18, the first switching signal 91 is supplied in an alternating scheme with the second switching signal 93. When the first switching signal 91 is equal to the ‘ON’ voltage Vsi, the second switching signal 93 is equal to zero volts. Similarly, when the second switching signal 93 is equal to the ‘ON’ voltage Vs2, the first switching signal 91 is equal to zero volts. The second switching signal 93 is also equal to zero volts between time intervals ti and t2, and ts and t4 outside of the above mentioned reduced time period.

In other words, the second switching signal 93 is equal to the ‘ON’ voltage Vs2 for a reduced time period less than the time intervals ti to t2, and ts to t4. This is illustrated in Figure 26 by the time gaps 2140, 2142. The second switching signal 93 includes a first time gap 2140 between ti and the start of the supply of the ‘ON’ voltage Vs2. The second switching signal 93 includes a second time gap 2142 between the end of the supply of the ‘ON’ voltage Vs2 and t2. During the first and second time gaps 2140, 2142, both the second switching signal 93 is equal to zero volts and the first switching signal 91 is equal to zero volts.

Therefore, during the first and second time gaps 2140, 2142, the first switching circuitry arrangement 85 and the second switching circuitry arrangement 86 prevent supply power to the first heating arrangement 164 and the second heating arrangement 144 respectively. Corresponding time gaps are also present during the time period between ts and t4.

By including the first and second time gaps 2140, 2142, the control circuitry may avoid any inadvertent overlap between the supply of power to the first heating arrangement 164 and the supply of power to the second heating arrangement 144. This may be particularly beneficial as the currents or voltages supplied to the first heating arrangement 164 or the second heating arrangement 144 may not instantaneously drop to zero once the supply of power to the first heating arrangement 164 or the second heating arrangement 144 is prevented by the first and second switching circuitry arrangements 85, 86.

Additionally, the reduced time period, or the first and second time gaps 2140, 2142, may be varied by the control circuitry, in order to control the temperature of the second heating arrangement 144. By adjusting the reduced time period or the first and second time gaps 2140, 2142, the control circuitry can maintain the temperature of the second heating arrangement 144 at a target temperature, or follow a target temperature profile, using pulsewidth modulation.

In this example, time intervals to to ti, and t2 to ts are approximately 20 milliseconds in length. In this example, time intervals ti to t2, and ts to t4 are approximately 70 milliseconds in length.

In addition to the pulse-width modulation control mode of adjusting the length of the reduced time period or the first and second time gaps 2140, 2142 described above, the control circuitry is configured to maintain the temperature of the first and second heating arrangements 164, 144 at corresponding target temperatures, or follow corresponding target temperature profiles, using pulse-width modulation by adjusting the length of the time intervals to to ti, and t2 to ts or ti to t2, and ts to t4. Although Figure 18 shows only single pulses during each of the on and off periods, the control circuitry may be configured to provide multiple pulse within each of the on and off periods. By providing multiple pulse within each of the on and off periods, the control circuitry can further control the heating of the first and second heating arrangements 164, 144 by for example modulating the width of each of the multiple pulse, or adjusting the proportion of each of the on or off periods which is occupied by the pulses.

When the scheme of switching voltages shown in Figure 26 is applied by the aerosolgenerating device according to the first embodiment, Figure 27 shows the resultant currents supplied to the first and second heating arrangements.

As a result of the first switching signal 91 supplied to the first switching circuitry arrangement 85, a first direct current IDCI is supplied to the first heating arrangement 164 over the time intervals to to ti and t2 to ts. The amplitude of the first direct current IDCI is constant over the time intervals to to ti and t2 to ts. The amplitude of the first direct current IDCI is zero over the time intervals ti to t2 and ts to t4.

As a result of the second switching signal 93 supplied to the second switching circuitry arrangement 86, a second direct current IDCI is supplied to the second heating arrangement 144 over the time intervals to to ti and t2 to ts.

The first and second time gaps 1040, 1042 are also illustrated in Figure 19, during which no current is supplied to the resistive heating element 1010.

The second direct current I DC2 is constant over the reduced time period during time intervals ti to t2 and ts to t4. The second direct current IDC2 is zero over the time intervals to to ti and t2 to ts.

In this embodiments, the first and second heating arrangements 164, 144 are both resistive heaters. The first and second direct currents would be replaced with first or second alternating currents should one of the first and second heating arrangements 164, 144 instead be an inductive heater as described herein. Similarly, the first and second direct currents would be replaced with first or second oscillating currents should one of the first and second heating arrangements 164, 144 instead be a dielectric heater as described herein.

Figure 28 illustrates a scheme of the first switching signal 91 and the second switching signal 93 supplied to the first switching circuitry arrangement 85 and the second switching circuitry arrangement 86 respectively, as well as an associated control signal 97 supplied from the first control unit 83 to the second control unit 84. The scheme illustrated in Figure 28 may be implemented in the control circuitry embodiments illustrated in Figures 23 or 25, which comprise a first control unit 83 and a second control unit 84.

The scheme illustrated in Figure 28 is similar to that described in Figure 26, so will be described with respect to its differences only. The control signal 97 comprises a control voltage, has a rectangular profile, and alternates between zero volts and an ‘ON’ voltage V_c.

The control signal 97 is equal to zero volts between time intervals to and ti, and t2 and ts, and is equal to the ‘ON’ voltage V_c between time intervals ti and t2, and ts and t4.

When the ‘ON’ voltage V_c is supplied from the first control unit 83 to the second control unit 84, the second control unit 84 is permitted to supply the second switching signal 93 comprising an ‘ON’ voltage Vs2to the second switching circuitry arrangement 86.

When the control signal 97 comprising zero volts is supplied from the first control unit 83 to the second control unit 84, the second control unit 84 is prevented from supplying the second switching signal 93 comprising an ‘ON’ voltage Vs2 to the second switching circuitry arrangement 86.

This ensures that the second switching circuitry arrangement 86 prevents the supply of power from the second DC power supply 82 (or first DC power supply 81 depending on the power supply system 40 configuration) to the second heating arrangement 144 between time intervals to and ti, and t2 and ts. This also ensures that the second switching circuitry arrangement 86 can only supply power from the second DC power supply 82 (or first DC power supply 81 depending on the power supply system 40 configuration) to the second heating arrangement 144 between time intervals ti and t2, and ts and t4, though it need not necessarily supply power from the second DC power supply 82 (or first DC power supply 81 depending on the power supply system 40 configuration) to the second heating arrangement 144 for the entirety of time intervals ti and t2, and ts and t4.

Advantageously, such an arrangement may synchronise the operation of the first and second heating arrangements 164, 144, without the requirement of the first control unit 83 and the second control unit 84 to both comprise synchronised timing means, such a separate synchronised clocks. In particular, the second control unit 84 need not comprise any timing means. The supply of the second switching signal 93 comprising an ‘ON’ voltage Vs2 to the second switching circuitry arrangement 86 can be trigged solely by the increase in the voltage of the control signal 97 from zero volts to the ‘ON’ voltage V_c. This simplifies the manufacture of the second control unit 84, and therefore of any such aerosol-generating device comprising said control circuitry.

For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number “A” is understood as “A” ± 10% of “A”. Within this context, a number “A” may be considered to include numerical values that are within general standard error for the measurement of the property that the number “A” modifies. The number “A,” in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which “A” deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

1. An aerosol-generating device for generating aerosol from an aerosol-generating article, the aerosol-generating device comprising; a first heating arrangement and a second heating arrangement configured for heating the aerosol-generating article when in use, the first heating arrangement and the second heating arrangement electrically connected to a first switching circuitry arrangement and second switching circuitry arrangement respectively; a power supply system configured to supply power to the first heating arrangement and the second heating arrangement, and a control system configured to control the supply of power from the power supply system to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively, wherein the first heating arrangement comprises an inductor element, and the second heating arrangement comprises an external resistive heating element.

2. An aerosol-generating device according to claim 1 , wherein the power supply system includes a first power supply configured to supply power to the first heating arrangement and the second heating arrangement.

3. An aerosol-generating device according to claim 2, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement and the second heating arrangement via the first switching circuitry arrangement and second switching circuitry arrangement respectively.

4. An aerosol-generating device according to claim 3, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the first control unit, and wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and control the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal.

5. An aerosol-generating device according to claim 3 or 4, wherein the first power supply is configured to supply power to the first control unit.

6. An aerosol-generating device according to claim 2, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and includes a second control unit configured to control the supply of power from the first power supply to the second heating arrangement via the second switching circuitry arrangement.

7. An aerosol-generating device according to claim 6, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the second control unit, wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and wherein the second control unit is configured to control the supply of power from the first power supply to the second heating arrangement dependent on the second feedback signal.

8. An aerosol-generating device according to claim 6 or 7, wherein the first control unit is configured to provide a control signal to the second control unit and the second control unit is configured to control the supply of power from the first power supply to the second heating arrangement dependent on the control signal, or wherein the second control unit is configured to provide a control signal to the first control unit and the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

9. An aerosol-generating device according to claim 1 , wherein the power supply system comprises a first power supply configured to supply power to the first heating arrangement, and a second power supply configured to supply power to the second heating arrangement.

10. An aerosol-generating device according to claim 9, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement.

11. An aerosol-generating device according to claim 10, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the first control unit, and wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and control the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

12. An aerosol-generating device according to claim 9, wherein the control system includes a first control unit configured to control the supply of power from the first power supply to the first heating arrangement via the first switching circuitry arrangement, and includes a second control unit configured to control the supply of power from the second power supply to the second heating arrangement via the second switching circuitry arrangement.

13. An aerosol-generating device according to claim 12, wherein the first switching circuitry arrangement is configured to provide a first feedback signal to the first control unit, and wherein the second switching circuitry arrangement is configured to provide a second feedback signal to the second control unit, wherein the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the first feedback signal, and wherein the second control unit is configured to control the supply of power from the second power supply to the second heating arrangement dependent on the second feedback signal.

14. An aerosol-generating device according to claim 12 or 13, wherein the first control unit is configured to provide a control signal to the second control unit and the second control unit is configured to control the supply of power from the second power supply to the second heating arrangement dependent on the control signal, or wherein the second control unit is configured to provide a control signal to the first control unit and the first control unit is configured to control the supply of power from the first power supply to the first heating arrangement dependent on the control signal.

15. An aerosol-generating device according to any preceding claim, wherein the inductor element is configured to inductively heat at least one internal susceptor element..