WO2025027281A1

WO2025027281A1 - Electronic circuitry and controllers for aerosol delivery systems

Info

Publication number: WO2025027281A1
Application number: PCT/GB2024/051939
Authority: WO
Inventors: Zehua JIANG; Chuanli NAN; Zhiqiang Yu; Changpeng YIN
Original assignee: Nicoventures Trading Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2023-07-28
Filing date: 2024-07-23
Publication date: 2025-02-06
Anticipated expiration: 2026-01-28

Abstract

Electronic circuitry for an aerosol delivery system configured to generate aerosol from aerosol-generating material in use, the circuitry comprising an aerosol generator (48) and a variable resistance component (170) or circuit connected in series with the aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator.

Description

ELECTRONIC CIRCUITRY AND CONTROLLERS FOR AEROSOL DELIVERY SYSTEMS

Field

The present disclosure relates to electronic circuitry and controllers for aerosol delivery systems such as, but not exclusively, nicotine delivery systems (e.g. e-cigarettes), as well as related methods.

Background

Aerosol delivery systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol generating material, such as a chamber of a source solid or liquid, which may contain an active substance and / or a flavour, from which an aerosol or vapour is generated for inhalation by a user, for example through heat vaporisation. Thus, an aerosol delivery system will typically comprise an aerosol generation area containing an aerosol generator, e.g. a heating element, arranged to vaporise or aerosolise a portion of precursor material to generate a vapour or aerosol in the aerosol generation area. As a user inhales on the device and electrical power is supplied to the vaporiser, air is drawn into the device through an inlet hole and along an inlet air channel connecting to the aerosol generation area, where the air mixes with vaporised precursor material to form a condensation aerosol. There is an outlet channel connecting the aerosol generation area to an outlet in the mouthpiece and the air drawn into the aerosol generation area as a user inhales on the mouthpiece continues along the outlet flow path to the mouthpiece outlet, carrying the aerosol with it, for inhalation by the user. Some electronic cigarettes may also include a flavour element in the air flow path through the device to impart additional flavours. Such devices may sometimes be referred to as hybrid devices, and the flavour element may, for example, include a portion of tobacco arranged in the air flow path between the aerosol generation area and the mouthpiece such that aerosol I condensation aerosol drawn through the device passes through the portion of tobacco before exiting the mouthpiece for user inhalation.

It is known to measure the resistance of an aerosol generator, e.g. by measuring a voltage across the aerosol generator using a voltage divider, to check its status. However, such arrangements may consume notable power. The present invention aims to improve the user experience by reducing power consumption, prolonging use time to provide an improved user experience and environmental benefits.

Terminology

Delivery System

As used herein, the term “delivery system” is intended to encompass systems that deliver at least one substance to a user in use, and includes: combustible aerosol provision systems, such as cigarettes, cigarillos, cigars, and tobacco for pipes or for roll-your-own or for make-your-own cigarettes (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco substitutes or other smokable material); non-combustible aerosol provision systems that release compounds from an aerosolgenerating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosolgenerating materials; and aerosol-free delivery systems that deliver the at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

Combustible Aerosol Provision System

According to the present disclosure, a “combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is combusted or burned during use in order to facilitate delivery of at least one substance to a user.

In some embodiments, the delivery system is a combustible aerosol provision system, such as a system selected from the group consisting of a cigarette, a cigarillo and a cigar. In some embodiments, the disclosure relates to a component for use in a combustible aerosol provision system, such as a filter, a filter rod, a filter segment, a tobacco rod, a spill, an aerosol-modifying agent release component such as a capsule, a thread, or a bead, or a paper such as a plug wrap, a tipping paper or a cigarette paper.

Non-Combustible Aerosol Provision System

According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system. In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosolgenerating material is not a requirement. In some embodiments, the non-combustible aerosol provision system is an aerosol-generating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system. In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol-generating material. The solid aerosolgenerating material may comprise, for example, tobacco or a non-tobacco product.

Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and a consumable for use with the non-combustible aerosol provision device. In some embodiments, the disclosure relates to consumables comprising aerosol-generating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.

In some embodiments, the non-combustible aerosol provision system, such as a non-combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent. In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.

Aerosol-Free Delivery System

In some embodiments, the delivery system is an aerosol-free delivery system that delivers at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

In some embodiments, the substance to be delivered may be an aerosol-generating material or a material that is not intended to be aerosolised. As appropriate, either material may comprise one or more active constituents, one or more flavours, one or more aerosol-former materials, and/or one or more other functional materials. Active Substance

In some embodiments, the substance to be delivered comprises an active substance. The active substance as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.

In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.

As noted herein, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes. As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term "botanical" includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like.

Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, Wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.

In some embodiments, the active substance comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is tobacco. In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from eucalyptus, star anise, cocoa and hemp. In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from rooibos and fennel.

Flavours

In some embodiments, the substance to be delivered comprises a flavour. As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, Wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas.

In some embodiments, the flavour comprises menthol, spearmint and/or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and/or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis.

In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucolyptol, WS-3.

Aerosol-generating material

Aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or gel which may or may not contain an active substance and/or flavourants. In some embodiments, the aerosol-generating material may comprise an “amorphous solid”, which may alternatively be referred to as a “monolithic solid” (i.e. non-fibrous). In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosol-generating material may for example comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid.

The aerosol-generating material may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional material.

Aerosol-former material

The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1 ,3-butylene glycol, erythritol, meso- Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

Functional material

The one or more other functional materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.

Substrate

The material may be present on or in a support, to form a substrate. The support may, for example, be or comprise paper, card, paperboard, cardboard, reconstituted material, a plastics material, a ceramic material, a composite material, glass, a metal, or a metal alloy. In some embodiments, the support comprises a susceptor. In some embodiments, the susceptor is embedded within the material. In some alternative embodiments, the susceptor is on one or either side of the material. Consumable

A consumable is an article comprising or consisting of aerosol-generating material, part or all of which is intended to be consumed during use by a user. A consumable may comprise one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generation area, a housing, a wrapper, a mouthpiece, a filter and/or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor.

Susceptor

A susceptor is a material that is heatable by penetration with a varying magnetic field, such as an alternating magnetic field. The susceptor may be an electrically-conductive material, so that penetration thereof with a varying magnetic field causes induction heating of the heating material. The heating material may be magnetic material, so that penetration thereof with a varying magnetic field causes magnetic hysteresis heating of the heating material. The susceptor may be both electrically-conductive and magnetic, so that the susceptor is heatable by both heating mechanisms. The device that is configured to generate the varying magnetic field is referred to as a magnetic field generator, herein.

Aerosol-modifying agent

An aerosol-modifying agent is a substance, typically located downstream of the aerosol generation area, that is configured to modify the aerosol generated, for example by changing the taste, flavour, acidity or another characteristic of the aerosol. The aerosol-modifying agent may be provided in an aerosol-modifying agent release component, that is operable to selectively release the aerosolmodifying agent. The aerosol-modifying agent may, for example, be an additive or a sorbent. The aerosol-modifying agent may, for example, comprise one or more of a flavourant, a colourant, water, and a carbon adsorbent. The aerosol-modifying agent may, for example, be a solid, a liquid, or a gel. The aerosol-modifying agent may be in powder, thread or granule form. The aerosol-modifying agent may be free from filtration material.

Aerosol generator

An aerosol generator is an apparatus configured to cause aerosol to be generated from the aerosolgenerating material. In some embodiments, the aerosol generator is a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol. In some embodiments, the aerosol generator is configured to cause an aerosol to be generated from the aerosol-generating material without heating. For example, the aerosol generator may be configured to subject the aerosol-generating material to one or more of vibration, increased pressure, or electrostatic energy.

The present disclosure relates to aerosol delivery systems (which may also be referred to as vapour delivery systems) such as nebulisers or e-cigarettes. Throughout the following description the term “e- cigarette” or “electronic cigarette” may sometimes be used, but it will be appreciated this term may be used interchangeably with aerosol delivery system I device and electronic aerosol delivery system I device. Furthermore, and as is common in the technical field, the terms "aerosol" and "vapour", and related terms such as "vaporise", "volatilise" and "aerosolise", may generally be used interchangeably.

Aerosol delivery systems (e-cigarettes) often, though not always, comprise a modular assembly comprising a reusable device part and a replaceable (disposable/consumable) cartridge part. Often, the replaceable cartridge part will comprise the aerosol generating material and the vaporiser (which may collectively be called a ‘cartomizer’) and the reusable device part will comprise the power supply (e.g. rechargeable power source) and control circuitry. It will be appreciated these different parts may comprise further elements depending on functionality. For example, the reusable device part will often comprise a user interface for receiving user input and displaying operating status characteristics, and the replaceable cartridge device part in some cases comprises a temperature sensor for helping to control temperature. Cartridges are electrically and mechanically coupled to the control unit for use, for example using a screw thread, bayonet, or magnetic coupling with appropriately arranged electrical contacts. When the aerosol generating material in a cartridge is exhausted, or the user wishes to switch to a different cartridge having a different aerosol generating material, the cartridge may be removed from the reusable part and a replacement cartridge attached in its place. Systems and devices conforming to this type of two-part modular configuration may generally be referred to as two-part systems/devices.

It is common for electronic cigarettes to have a generally elongate shape. For the sake of providing a concrete example, certain embodiments of the disclosure will be taken to comprise this kind of generally elongate two-part system employing disposable cartridges. However, it will be appreciated that the underlying principles described herein may equally be adopted for different configurations, for example single-part systems or modular systems comprising more than two parts, refillable devices and single-use disposables, as well as other overall shapes, for example based on so-called box-mod high performance devices that typically have a boxier shape. More generally, it will be appreciated certain embodiments of the disclosure are based on aerosol delivery systems which are operationally configured to provide functionality in accordance with the principles described herein and the constructional aspects of systems configured to provide the functionality in accordance with certain embodiments of the disclosure is not of primary significance. Brief summary of the invention

The present invention provides electronic circuitry for an aerosol delivery system configured to generate aerosol from aerosol-generating material in use, the circuitry comprising an aerosol generator; and a variable resistance component or circuit connected in series with the aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator.

The present invention further provides a controller for an aerosol delivery system comprising a variable resistance component or circuit connected in series with an aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator in use, wherein the controller is configured to adjust the variable resistance for determining a voltage across the aerosol generator.

The present invention further provides a method of controlling an aerosol delivery system comprising a variable resistance component or circuit connected in series with an aerosol generator in use, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator in use, the method comprising adjusting the variable resistance for determining a voltage across the aerosol generator.

The present invention further provides additional embodiments as claimed in the dependent claims.

The claimed invention generally provides circuitry, a sub-assembly or sub-system suitable for use in an aerosol delivery system, or configured for use in an aerosol delivery system. The sub-system may generally form part of an aerosol delivery system and in particular may form part of the reusable device and/or the consumable cartridge.

The claimed arrangement beneficially reduces power consumption, prolonging use time providing an improved user experience and environmental benefits.

Brief description of the figures

Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic cross-section view of an aerosol delivery system in accordance with some embodiments of the disclosure;

Figure 2 is a schematic of electronic circuitry in accordance with some embodiments of the disclosure; Figure 3a is a schematic flow chart illustrating a first cyclic control method in accordance with some embodiments of the disclosure;

Figure 3b is a schematic flow chart illustrating a second cyclic control method in accordance with some embodiments of the disclosure;

Figure 4a is a schematic time plot illustrating smoking status, control circuit status and variable resistance value against time in accordance with some embodiments of the disclosure;

Figure 4b is a schematic illustration of a variable resistance circuit in accordance with some embodiments of the disclosure;

Figures 5a and 5b are schematic flow charts illustrating the status of the variable resistance circuit in non-measuring and measuring states respectively; and

Figure 6 is a schematic circuit diagram in accordance with a particular embodiment of the disclosure.

Detailed description of the disclosure

Aspects and features of certain examples and embodiments are described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not described in detail in the interest of brevity. It will thus be appreciated that aspects and features of apparatuses and methods discussed herein which are not described in detail may be implemented in accordance with any suitable conventional techniques.

Figure 1 is a cross-sectional view through an example aerosol delivery system 1 in accordance with certain embodiments of the disclosure, providing an introduction to two-part aerosol delivery systems, the components therein and their functionality.

The aerosol delivery system 1 comprises two main parts, namely a reusable part 2 and a replaceable I disposable consumable cartridge part 4. In normal use, the reusable part 2 and the cartridge part 4 are releasably coupled together at an interface 6. When the cartridge part 4 is exhausted or the user simply wishes to switch to a different cartridge part 4, the cartridge part 4 may be removed from the reusable part 2 and a replacement cartridge part 4 attached to the reusable part 2 in its place. The interface 6 provides a structural, electrical and airflow path connection between the two parts 2, 4 and may be established in accordance with conventional techniques, for example based around a screw thread, magnetic or bayonet fixing with appropriately arranged electrical contacts and openings for establishing the electrical connection and airflow path between the two parts 2, 4 as appropriate. The specific manner by which the cartridge part 4 mechanically mounts to the reusable part 2 is not significant to the principles described herein, but for the sake of a concrete example is assumed here to comprise a magnetic coupling (not represented in figure 1). It will also be appreciated the interface 6 in some implementations may not support an electrical and I or airflow path connection between the respective parts 2, 4. For example, in some implementations an aerosol generator may be provided in the reusable part 2 rather than in the cartridge part 4, or the transfer of electrical power from the reusable part 2 to the cartridge part 4 may be wireless (e.g. based on electromagnetic induction), so that an electrical connection between the reusable part 2 and the cartridge part 4 is not needed. Furthermore, in some implementations the airflow through the electronic cigarette might not go through the reusable part 2, so that an airflow path connection between the reusable part 2 and the cartridge part 4 is not needed. In some instances, a portion of the airflow path may be defined at the interface between portions of the reusable part 2 and cartridge part 4 when these are coupled together for use.

The cartridge I consumable part 4 may, in certain embodiments, be broadly conventional. In figure 1 , the cartridge part 4 comprises a cartridge housing 42 formed of a plastics material. The cartridge housing 42 supports other components of the cartridge part 4 and provides the mechanical interface 6 with the reusable part 2. The cartridge housing 42 is generally circularly symmetrical about a longitudinal axis along which the cartridge part 4 couples to the reusable part 2. In this example, the cartridge part 4 has a length of around 4 cm and a diameter of around 1 .5 cm. However, the specific geometry and the overall shapes and materials used may vary.

Within the cartridge housing 42 is a chamber or reservoir 44 that contains aerosol-generating material. In the example of figure 1 , the reservoir 44 stores a supply of liquid aerosol generating material. In this example, the liquid reservoir 44 has an annular shape with an outer wall defined by the cartridge housing 42 and an inner wall that defines an airflow path 52 through the cartridge part 4. The reservoir 44 is closed at each end with end walls to contain the aerosol generating material. The reservoir 44 may be formed in accordance with conventional techniques, for example it may comprise a plastics material and be integrally moulded with the cartridge housing 42.

The cartridge I consumable part 4 further comprises an aerosol generator 48 located towards an end of the reservoir 44 opposite to a mouthpiece outlet 50. It will be appreciated that in a two-part system such as shown in figure 1 , the aerosol generator 48 may be in either of the reusable part 2 or the cartridge part 4. For example, in some embodiments, the aerosol generator 48 (e.g. a heater, which may be in the form of a wick and coil arrangement as shown, a distiller, which may be formed from a sintered metal fibre material or other porous conducting material, or any suitable alternative aerosol generator) may be comprised in the reusable part 2, and is brought into proximity with a portion of aerosol generating material in the cartridge part 4 when the cartridge part 4 is engaged with the reusable part 2. In such embodiments, the cartridge part 4 may comprise a portion of aerosol generating material, and an aerosol generator 48 comprising a heater is at least partially inserted into or at least partially surrounds the portion of aerosol generating material as the cartridge part 4 is engaged with the reusable part 2. In the example of figure 1 , a wick 46 in contact with the aerosol generator 48 extends transversely across the cartridge airflow path 52 with its ends extending into the reservoir 44 of the liquid aerosol generating material through openings in the inner wall of the reservoir 44. The openings in the inner wall of the reservoir 44 are sized to broadly match the dimensions of the wick 46 to provide a reasonable seal against leakage from the liquid reservoir 44 into the cartridge airflow path without unduly compressing the wick 46, which may be detrimental to its fluid transfer performance.

The wick 46 and aerosol generator 48 are arranged in the cartridge airflow path 52 such that a region of the cartridge airflow path 52 around the wick 46 and heater 48 in effect defines a vaporisation region for the cartridge part 4. Aerosol generating material in the reservoir 44 infiltrates the wick 46 through the ends of the wick extending into the reservoir 44 and is drawn along the wick by surface tension I capillary action (i.e. wicking). The aerosol generator 48 in this example comprises an electrically resistive wire coiled around the wick 46. In figure 1 , the heater 48 comprises a nickel chrome alloy (Cr20Ni80) wire and the wick 46 comprises a glass fibre bundle, but the specific aerosol generator configuration is not significant to the principles described herein. Rather, the circuitry comprising a variable resistance component or circuit 170 (not shown in figure 1) connected in series with the aerosol generator 48, the variable resistance component or circuit 170 having a variable resistance and forming a variable voltage divider for determining a voltage across the aerosol generator 48, is a core aspect of the invention and is described further with reference to the subsequent figures below.

In use, electrical power may be supplied to the aerosol generator 48 to vaporise an amount of aerosol generating material (aerosol generating material) drawn to the vicinity of the aerosol generator 48 by the wick 46. Vaporised aerosol generating material may then become entrained in air drawn along the cartridge airflow path from the vaporisation region towards the mouthpiece outlet 50 for user inhalation.

As noted above, the rate at which aerosol generating material is vaporised by the aerosol generator 48 will depend on the amount (level) of power supplied to the aerosol generator 48. Thus electrical power can be applied to the aerosol generator 48 to selectively generate aerosol from the aerosol generating material in the cartridge part 4, and furthermore, the rate of aerosol generation can be changed by changing the amount of power supplied to the aerosol generator 48, for example through pulse width and/or frequency modulation techniques.

The reusable part 2 comprises an outer housing 12 having with an opening that defines an air inlet 28 for the e-cigarette, a power source 26 (e.g. a battery) for providing operating power for the electronic cigarette, control circuitry / controller 22 for controlling and monitoring the operation of the electronic cigarette, a first user input button 14, a second user input button 16, and a visual display 24. The outer housing 12 may be formed, for example, from a plastics or metallic material and in this example has a circular cross section generally conforming to the shape and size of the cartridge part 4 so as to provide a smooth transition between the two parts 2, 4 at the interface 6. In this example, the reusable part 2 has a length of around 8 cm so the overall length of the e-cigarette when the cartridge part 4 and the reusable part 2 are coupled together is around 12 cm.

The air inlet 28 connects to an airflow path 51 through the reusable part 2. The reusable part airflow path 51 in turn connects to the cartridge airflow path 52 across the interface 6 when the reusable part 2 and cartridge part 4 are connected together. Thus, when a user inhales on the mouthpiece opening 50, air is drawn in through the air inlet 28, along the reusable part airflow path 51 , across the interface 6, through the aerosol generation area in the vicinity of the aerosol generator 48 (where vaporised aerosol generating material becomes entrained in the air flow), along the cartridge airflow path 52, and out through the mouthpiece opening 50 for user inhalation.

The power source 26 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods. The power source 26 may be recharged through a charging connector in the reusable part housing 12, for example a USB connector.

Optionally, first and/or second user input buttons 14, 16 may be provided, which in this example are conventional mechanical buttons, for example comprising a spring mounted component which may be pressed by a user to establish an electrical contact. In this regard, the input buttons may be considered input devices for detecting user input and the specific manner in which the buttons are implemented is not significant. The buttons may be assigned to functions such as switching the aerosol delivery system 1 on and off, and adjusting user settings such as a power to be supplied from the power source 26 to the aerosol generator 48.

A display 24 may be provided to give a user with a visual indication of various characteristics associated with the aerosol delivery system, for example current power setting information, remaining power source power, and so forth. The display may be implemented in various ways. In this example the display 24 comprises a conventional pixilated LCD screen that may be driven to display the desired information in accordance with conventional techniques. In other implementations, the display may comprise one or more discrete indicators, for example LEDs, that are arranged to display the desired information, for example through particular colours and I or flash sequences. More generally, the manner in which the display 24 is provided and information is displayed to a user using the display is not significant to the principles described herein. For example, some embodiments may not include a visual display and/or may include other means for providing a user with information relating to operating characteristics of the aerosol delivery system, for example using audio signalling, or may not include any means for providing a user with information relating to operating characteristics of the aerosol delivery system. A controller 22 is suitably configured / programmed to control the operation of the aerosol delivery system 1 to provide functionality as described herein, as well as for providing conventional operating functions of the aerosol delivery system 1 . The controller (processor circuitry) 22 may be considered to logically comprise various sub-units I circuitry elements associated with different aspects of the operation of the aerosol delivery system 1 . In this example the controller 22 comprises power supply control circuitry for controlling the supply of power from the power source 26 to the aerosol generator 48 in response to user input, user programming circuitry 20 for establishing configuration settings (e.g. user-defined power settings) in response to user input, as well as other functional units I circuitry associated functionality in accordance with the principles described herein and conventional operating aspects of electronic cigarettes, such as display driving circuitry and user input detection circuitry. The functionality of the controller 22 can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and I or one or more suitably configured application-specific integrated circuit(s) I circuitry I chip(s) I chipset(s).

The controller 22 may comprise an application specific integrated circuit (ASIC) or microcontroller, for controlling the aerosol delivery device. The microcontroller or ASIC may include a CPU or microprocessor. The operations of a CPU and other electronic components are generally controlled at least in part by software programs running on the CPU (or other component). Such software programs may be stored in non-volatile memory, such as ROM, which can be integrated into the microcontroller itself, or provided as a separate component. The CPU may access the ROM to load and execute individual software programs as and when required.

The reusable part 2 comprises an airflow sensor 30 which is electrically connected to the controller 22. In most embodiments, the airflow sensor 30 comprises a so-called “puff sensor”, in that the airflow sensor 30 is used to detect when a user is puffing on the device. In some embodiments, the airflow sensor 30 comprises a switch in an electrical path providing electrical power from the power source 26 to the aerosol generator 48. In such embodiments, the airflow sensor 30 generally comprises a pressure sensor configured to close the switch when subjected to a particular range of pressures, enabling current to flow from the power source 26 to the aerosol generator 48 once the pressure in the vicinity of the airflow sensor 30 drops below a threshold value. The threshold value can be set to a value determined by experimentation to correspond to a characteristic value associated with the initiation of a user puff. In other embodiments, the airflow sensor 30 is connected to the controller 22, and the controller distributes electrical power from the power source 26 to the aerosol generator 48 in dependence of a signal received from the airflow sensor 30 by the controller 22. The specific manner in which the signal output from the airflow sensor 30 (which may comprise a measure of capacitance, resistance or other characteristic of the airflow sensor, made by the controller 22) is used by the controller 22 to control the supply of power from the power source 26 to the aerosol generator 48 can be carried out in accordance with any approach known to the skilled person. In the example shown in figure 1 , the airflow sensor 30 is mounted to a printed circuit board (PCB) 31 , but this is not essential. The airflow sensor 30 may comprise any sensor which is configured to determine a characteristic of airflow in an airflow path 51 disposed between air inlet 28 and mouthpiece opening 50, for example a pressure sensor or transducer (for example a membrane or solid-state pressure sensor), a combined temperature and pressure sensor, or a microphone (for example an electret-type microphone), which is sensitive to changes in air pressure, including acoustical signals. The airflow sensor 30 is situated within a sensor cavity or chamber 32, which comprises the interior space defined by one or more chamber walls 34. The sensor cavity 32 comprises a region internal to one or more chamber walls 34 in which an airflow sensor 30 can be fully or partially situated. In some embodiments, the PCB 31 comprises one of the chamber walls of a sensor housing comprising the sensor chamber I cavity 32.

A deformable membrane is disposed across an opening communicating between the sensor cavity 32 containing the sensor 30, and a portion of the airflow path disposed between air inlet 28 and mouthpiece opening 50. The deformable membrane covers the opening, and is attached to one or more of the chamber walls according to approaches described further herein.

As described further herein, the aerosol delivery system 1 comprises communication circuitry configured to enable a connection to be established with one or more further electronic devices (for example, a storage I charging case, and / or a refill I charging dock) to enable data transfer between the aerosol delivery system 1 and further electronic device(s). In some embodiments, the communication circuitry is integrated into controller 22, and in others it is implemented separately. For example, the communication circuitry may comprise a separate module to the controller 22 which, while connected to controller 22, provides dedicated data transfer functionality for the aerosol delivery device. In some embodiments, the communication circuitry is configured to support communication between the aerosol delivery system 1 and one or more further electronic devices over a wireless interface. The communication circuitry may be configured to support wireless communications between the aerosol delivery system 1 and other electronic devices such as a case, a dock, a computing device such as a smartphone or PC, a base station supporting cellular communications, a relay node providing an onward connection to a base station, a wearable device, or any other portable or fixed device which supports wireless communications.

The controller 22, other components within the system 1 and other devices/systems may comprise one or more processors and data processing steps may be performed on any of these processors or on a remote processor, the data communicated by wire or wirelessly.

Wireless communications between the aerosol delivery system 1 and a further electronic device may be configured according to data transfer protocols such as Bluetooth®, ZigBee, WiFi®, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC, RFID, or generally any other wireless, and/or wired, network protocol or interface. The communication circuitry may comprise any suitable interface for wired data connection, such as USB-C, micro-USB or Thunderbolt interfaces, and may comprise pin or contact pad arrangements configured to engage cooperating pins or contact pads on a dock, case, cable, or other external device which can be connected to the aerosol delivery system 1 .

Independent embodiments of the disclosure include electronic circuitry for an aerosol delivery system configured to generate aerosol from aerosol-generating material in use, the circuitry comprising: an aerosol generator; and a variable resistance component or circuit connected in series with the aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator. Such an arrangement reduces power consumption of the system because the resistance can be varied depending on whether or not a voltage across the aerosol generator is being determined.

Further independent embodiments include controllers for aerosol delivery systems comprising a variable resistance component or circuit connected in series with an aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator in use, wherein the controller is configured to adjust the variable resistance for determining a voltage across the aerosol generator.

Figure 2 is a schematic of electronic circuitry in accordance with some embodiments of the disclosure.

Figure 2 illustrates electronic circuitry in an aerosol delivery system 1 configured to generate aerosol from aerosol-generating material in use, the circuitry comprising the following, connected in series: a power supply 26, for supplying power to an aerosol generator 48; a power supply control circuit 120, for controlling the supply of power to the aerosol generator 48 (thus may also be considered as an aerosol generator control circuit); an aerosol generator 48; and a variable resistance component or circuit 170.

The power supply 26 and aerosol generator 48 may be broadly conventional in some embodiments. The power supply control circuit 120 may also be broadly conventional in some embodiments and may comprise a switch in its simplest form, thus providing a switch circuit 120, which may control the supply of power to the aerosol generator 48 e.g. using PWM. In some examples, the power supply control circuitry 120 comprises a transistor, such as a MOSFET and/or may comprise a resistor e.g. in parallel with the transistor.

The circuitry of figure 2 additionally comprises a control unit I controller 22 (which may be a microcontroller or MCU 22) connected to both the power supply control circuit 120 and the variable resistance component or circuit 170. The controller 22 can selectively enable/disable these circuits 120, 170. The circuitry of figure 2 additionally comprises an analogue-to-digital converter (ADC) between the controller 22 and the variable resistance component or circuit 170, which may be provided e.g. for the controller 22 to calculate the resistance of the aerosol generator 48 based on a voltage across the aerosol generator 48. Equally, a digital-to-analogue converter (DAC) may be provided, as needed.

As outlined above, the aerosol delivery system 1 may be modular and particularly may comprise a reusable device part 2 comprising the power supply 26 and optionally the power supply control circuit 120, and a consumable/replaceable cartridge part 4 comprising the aerosol-generating material, and optionally the aerosol generator 48 itself. In particular, the aerosol generator 48, one or more controllers 22, the power supply control circuit 120 and the variable resistance component or circuit 170 may be provided in either part 2, 4.

A first set of embodiments of the disclosure comprise electronic circuitry for an aerosol delivery system 1 configured to generate aerosol from aerosol-generating material in use, the circuitry comprising an aerosol generator 48 and a variable resistance component or circuit 170 connected in series with the aerosol generator 48 in use, the variable resistance component or circuit 170 having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator 48. As such, the power supply 26, the power supply control circuit 120 and the controllers) 22, which may be conventional, are not essential to these embodiments.

In some embodiments, the variable resistance component or circuit 170 comprises one or more of: a variable resistor, a transistor; and/or an application-specific integrated circuit (ASIC). Further specific implementations are discussed with reference to the subsequent figures.

The variable resistance component or circuit 170 is variable or switchable between a very small/low resistance (close to 0 Q) for when in a non-measuring state (including when supplying power to the aerosol generator 48 generate aerosol), to reduce power consumption, and a ‘standard’/high (high relative to the low) resistance, such as 4.7 Q, for when determining a voltage across the aerosol generator 48. A total resistance of 4.7 Q is particularly suitable when a total resistance of the aerosol generator 48 is approximately within the range of 0.7-1 .5 Q.

Accordingly, relatively speaking, the variable resistance is thus variable between a first, ‘high’ resistance and a second, ‘low’ resistance. The high resistance may generally be > 1 Q, e.g. substantially within the range of 1-10 Q, whilst the low resistance may generally be < 1 Q, e.g. substantially within the range of 0-1 Q; and/or the low resistance may be substantially a minimal resistance for the variable resistance component or circuit 170. Likewise, the high resistance may be substantially a maximum resistance for the variable resistance component or circuit 170.

Further embodiments of the disclosure comprise a controller 22 for an aerosol delivery system 1 comprising a variable resistance component or circuit 170 connected in series with an aerosol generator 48, the variable resistance component or circuit 170 having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator 48 in use, wherein the controller 22 is configured to adjust the variable resistance for determining a voltage across the aerosol generator 48.

Additional embodiments of the disclosure include a control method, which will now be described in more detail with reference to figures 3a and 3b.

Figure 3a is a schematic flow chart illustrating a first cyclic control method for setting/adjusting the variable resistance for determining a resistance of the aerosol generator 48, or (optionally) more specifically for measuring a voltage across the aerosol generator 48, from which the resistance can be calculated. The resistance of the aerosol generator 48 is preferably determined by measuring a voltage across the aerosol generator 48 and then the resistance can be calculated based on the voltage using Ohm’s law.

Figure 3a shows that in some embodiments, the system 1 or controller 22 is configured to set the variable resistance depending on whether or not a voltage/resistance is being determined. More specifically, the system 1 or controller 22 may be configured to set the variable resistance to a first, standard/high resistance for determining a voltage across the aerosol generator 48; and configured to set the variable resistance to a second, low resistance for when not determining a voltage across the aerosol generator 48, to minimise power consumption.

In some embodiments, the system 1 or controller 22 is configured to restart the loop (checking the measuring state) as soon as the voltage across the aerosol generator 48 has been measured. Optionally, the system 1 or controller 22 may calculate the resistance of the aerosol generator 48 based on the measured voltage before restarting the loop.

Figure 3b is a schematic flow chart illustrating a second cyclic control method in accordance with some embodiments of the disclosure. Figure 3b includes similar steps shown in figure 3a (also described further later), preceded by a first step in which the system 1 (e.g. the controller 22) checks if a user is smoking/puffing on the system 1 (e.g. by detecting puffing automatically, such as by using a puff or air flow sensor 30, or e.g. receiving a manual user input indicating they are smoking).

In figure 3b, the system 1 or the controller 22 preferably selectively enables the power supply control circuit 120 when puffing is detected and then proceeds to the measuring state check, or if puffing is not detected, then disables the power supply control circuit 120 and restarts the loop, i.e. re-checking the smoking state. Accordingly, the power supply control circuit 120 is preferably only enabled when the user is smoking e.g. puffing is detected. More specifically, the system 1 or controller 22 may be configured to determine when a user starts puffing, is puffing, finishes puffing and/or is not puffing on the aerosol delivery system 1 and to enable the power supply control circuitry 120 when the user starts or is puffing and/or disable the power supply control circuitry 120 when the user finishes or is not puffing.

In the figure 3b method, when puffing/smoking is detected and the power supply control circuit 120 is enabled, the system 1 or the controller 22 switches or varies the resistance between the low and standard/high resistance values, depending on whether or not a voltage across or resistance of the aerosol generator 48 is being determined, similar to as in figure 3a. However, in figure 3b, after determining the voltage across or resistance of the aerosol generator 48, there are two routes, contrasting to figure 3a. In one variant (shown in solid lines), the loop restarts and the system rechecks the smoking and measuring states. In an alternative variant (shown in dashed lines) the system 1 switches or varies the variable resistance to the second, low resistance as soon as a voltage measurement has been taken or resistance calculated, without first re-checking the smoking and measuring states, ready for power supply to the aerosol generator without unnecessary power consumption. Figure 3b also includes this subsequent power supply step (aerosol generator active).

Typically, the system 1 will determine the resistance of the aerosol generator 48 before supplying power to the aerosol generator 48 for aerosol generation, to establish the status of the aerosol generator 48 and suitably adjust the power supply thereto, and then periodically, at regular or irregular intervals during puffing, re-check the voltage/resistance to ascertain the updated status of the aerosol generator 48. Accordingly, the system 1 or controller 22 may be configured to temporarily set the variable resistance to a high resistance when determining the resistance of the aerosol generator 48 (or more specifically, when determining a voltage across the aerosol generator 48, but not necessarily whilst subsequently determining the resistance based on the measured voltage, which may be performed by the system 1 , the controller 22 or another controller), and thereafter set the variable resistance to a second, low resistance.

In some embodiments, the system 1 or the same controller 22 is configured to determine the voltage across the aerosol generator 48, determine the resistance of the aerosol generator 48; and/or control the supply of power to the aerosol generator 48, dependent on the voltage across or resistance of the aerosol generator 48. In other embodiments, these steps may be performed by a separate controller 22.

Furthermore, in some embodiments, the system 1 or the controller 22 may be further configured to adjust one or more operating parameters of the aerosol delivery system 1 , dependent on the voltage across or resistance of cartridge, particularly when the cartridge contains the aerosol generator 48 (and therefore the measured voltage across the cartridge indicates the voltage across the aerosol generator 48). The operating parameters may include any parameters for the aerosol generator 48, such as the power supply profile therefor (i.e. the voltage or current supply profile over time, which may depend on the resistance of the aerosol generator 48, particularly if a particular operating temperature of the aerosol generator 48 is desired), and/or other operating parameters such as rate of supply or mixture of aerosol generating material (which might be adjustable e.g. via a valve) air flow into I aerosol flow out of the system (either of which might be adjustable by baffles), etc.

Accordingly, in one particular embodiment, the controller 22 or system 1 is configured to: a. determine when a user starts puffing on the system; b. set the variable resistance to a first, high resistance for determining a voltage across the aerosol generator; c. determine the voltage across the aerosol generator and then set the variable resistance to a second, low resistance; d. determine the resistance of the aerosol generator based on the determined voltage; and e. control a supply of power to the aerosol generator dependent on the resistance of the aerosol generator.

In a further particular embodiment, the controller 22 or system 1 is configured to determine when the user is puffing on the system, and configured to periodically, during puffing: a. set the variable resistance to a first, high resistance for determining a voltage across the aerosol generator; b. determine the voltage across the aerosol generator and then set the variable resistance to a second, low resistance after determining the voltage across the aerosol generator; c. determine the resistance of the aerosol generator based on the determined voltage; and d. control a supply of power to the aerosol generator dependent on the resistance of the aerosol generator.

Figure 4a is a schematic time plot illustrating smoking status, status of the power supply control circuit 120 and the resistance value of the variable resistance component or circuit 170 against time. As shown in figure 4a, the smoking status is a binary status: either smoking or not smoking. The power supply control circuit 120 status follows the binary smoking status, i.e. is enabled when smoking, and disabled when not smoking, minimising power consumption for this circuit 120. The variable resistance of the variable resistance component or circuit 170 is switched or adjusted during smoking to provide a standard resistance when measuring a voltage across/resistance of the aerosol generator 48, and a minimal resistance otherwise, i.e. when not measuring a voltage across/resistance of the aerosol generator 48.

Figure 4b is a schematic illustration of a particular variable resistance circuit 170. Figure 4b illustrates the variable resistance component or circuit 170 generally comprising a N-type or P-type metal oxide semiconductor (NMOS or PMOS) field effect transistor (FET), with a resistor connected in parallel thereto (providing a voltage divider in the implementation of figure 6). In figure 4b, the MOSFET (Q3) is a PMPB23XNE single N-channel Trench MOSFET, and the resistor has a resistance rating of 4.7 Q as one particular example.

In the non-measuring state, as shown in figure 5a, the MOSFET is turned on, and the total resistance value of the circuit 170 (comprising the 4.7 Q resistor and MOSFET) is very small, thereby minimising power consumption. In the measuring state, as shown in figure 5b, the MOSFET is turned off, providing a standard resistance (substantially the total connected resistance value, 4.7 Q in figure 4b), providing a suitable resistance to accurately and reliably measure a voltage across the aerosol generator 48. Accordingly, in this example, the MCU can control the switching state of the MOSFET to alter the resistance.

Figure 6 is a schematic circuit diagram in accordance with a particular embodiment of the disclosure, providing a working example.

In figure 6, the power supply 26 comprises a 4.2 V voltage source supplying power to the system 1 , feeding the power supply control circuit 120. The power supply control circuit 120 comprises a PMOS transistor connected to the output of a two-input NAND gate receiving signals from both a puff sensor 30, in this case a microphone, and a PWM control (from the MCU 22). A 10 kQ resistor is connected between the voltage source and the NAND output, in parallel with the PMOS transistor. As such, in this example, the PMOS transistor is controlled by the puff sensor and PWM signals, e.g. the PMOS is turned on only when both the puff sensor and PWM signals are high level. In other arrangements, different power supply control circuits 120 may be provided (e.g. utilising different logic gates) and/or other supply voltages may be used, typically within the range of 3-6 V.

In figure 6, the aerosol generator 48 is connected in series with the PMOS transistor of the power supply control circuit 120, the aerosol generator 48 comprising a resistance heater in the form of a 1 .4 Q resistor.

The aerosol generator 48 is connected in series with the variable resistance component or circuit 170, which comprises the circuitry of figure 4b (comprising a MOSFET with a voltage dividing resistor R2 connected in parallel thereto), connected to ground. As shown in figure 6, power is supplied to the variable resistance component or circuit 170 from the 4.2 V supply, with an optional 10 kQ resistor R3 connected in series with the MOSFET.

The resistor R2 of the circuit 170 provides a first voltage divider for the MCU (via an ADC) connection as shown, with the connection to the MCU between the aerosol generator 48 and the resistor R2 comprising a further (second) voltage divider, with a first resistor R4 (2 kQ) and a second resistor R5 (1 kQ) connected in series with R4 and connected to ground, where the MCU is connected between R4 and R5 (via an ADC). For the avoidance of doubt, the specific values described herein e.g. for resistance and voltage, are to provide a concrete example and are not limiting: other values may be used, in any combinations. The terms ‘circuit’ and ‘circuitry’ are used interchangeably. Furthermore, any specific directional flow pathways between components is not limiting: both specific one-way communication and two-way communication between any components and/or combinations thereof are explicitly contemplated.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. Any functions of a processor (e.g. controller) may be shared between processors on the various devices/systems in the wider system and/or a remote server. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention.

Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future. Protection may also be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure.

Index to reference numerals

1 aerosol delivery system

2 reusable part

4 cartridge part

6 interface between reusable part and cartridge part

12 reusable part housing

14, 16 user input buttons

20 user programming circuitry

22 controller

24 display

26 power source

28 air inlet

30 airflow sensor

31 printed circuit board (PCB)

32 sensor cavity or chamber

34 chamber wall 42 cartridge housing

44 chamber or reservoir

46 wick

48 aerosol generator 50 mouthpiece outlet

51 airflow path through reusable part

52 airflow path through cartridge

120 power supply control circuit/circuitry

170 variable resistance component or circuit/circuitry

Claims

1 . Electronic circuitry for an aerosol delivery system configured to generate aerosol from aerosol-generating material in use, the circuitry comprising: a. an aerosol generator; and b. a variable resistance component or circuit connected in series with the aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator.

2. The circuitry of claim 1 , wherein the variable resistance component or circuit comprises: a. a variable resistor; and/or b. a transistor; and/or c. an application-specific integrated circuit (ASIC).

3. The circuitry of claim 2, wherein the variable resistance component or circuit comprises: a. an N-type or P-type metal oxide semiconductor (NMOS or PMOS) field effect transistor (FET) with a voltage dividing resistor connected in parallel thereto.

4. The circuitry of any preceding claim, wherein the variable resistance is variable between a first, high resistance and a second, low resistance.

5. The circuitry of claim 4, wherein: a. the high resistance is substantially within the range of 1-10 Q; and/or b. the low resistance is substantially within the range of 0-1 Q; and/or c. the low resistance is substantially a minimal resistance for the variable resistance component or circuit.

6. A controller for an aerosol delivery system comprising a variable resistance component or circuit connected in series with an aerosol generator, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator in use, wherein the controller is configured to: a. adjust the variable resistance for determining a voltage across the aerosol generator.

7. An aerosol delivery system comprising the circuitry of any preceding claim and the controller of claim 6.

8. The controller or aerosol delivery system of claim 6 or 7, wherein the controller or the system is configured to set the variable resistance depending on whether or not a voltage across the aerosol generator is being determined.

9. The controller or aerosol delivery system of claim 6, 7 or 8, wherein the controller or system is configured to: a. set the variable resistance to a first, high resistance when determining a voltage across the aerosol generator; and b. set the variable resistance to a second, low resistance when not determining a voltage across the aerosol generator.

10. The controller or aerosol delivery system of any of claims 6 to 9, wherein the controller or system is configured to: a. temporarily set the variable resistance to a high resistance when determining a voltage across the aerosol generator; and b. after determining the voltage across the aerosol generator, set the variable resistance to a second, low resistance.

11 . The aerosol delivery system of any preceding claim, comprising a puff sensor for detecting when a user is puffing on the system.

12. The controller or aerosol delivery system of any of claims 6 to 11 , wherein the controller or system is configured to: a. determine when a user starts puffing, is puffing, finishes puffing and/or is not puffing on the aerosol delivery system; and/or b. determine the voltage across the aerosol generator; and/or c. determine the resistance of the aerosol generator; and/or d. control a supply of power to the aerosol generator dependent on the voltage across or resistance of the aerosol generator.

13. The controller or aerosol delivery system of any of claims 6 to 12, wherein the controller or system is configured to determine when the user is puffing on the system and: a. enable power supply control circuitry when the user starts or is puffing; and/or b. disable power supply control circuitry when the user finishes or is not puffing.

14. The controller or aerosol delivery system of any of claims 6 to 13, wherein the controller or system is configured to: a. determine when a user starts puffing on the system; b. set the variable resistance to a first, high resistance for determining a voltage across the aerosol generator; c. determine the voltage across the aerosol generator and then set the variable resistance to a second, low resistance; d. determine the resistance of the aerosol generator based on the determined voltage; and e. control a supply of power to the aerosol generator dependent on the resistance of the aerosol generator.

15. The controller or aerosol delivery system of any of claims 6 to 14, wherein the controller or system is configured to determine when the user is puffing on the system, and configured to periodically, during puffing: a. set the variable resistance to a first, high resistance for determining a voltage across the aerosol generator; b. determine the voltage across the aerosol generator and then set the variable resistance to a second, low resistance after determining the voltage across the aerosol generator; c. determine the resistance of the aerosol generator based on the determined voltage; and d. control a supply of power to the aerosol generator dependent on the resistance of the aerosol generator.

16. The controller or aerosol delivery system of any of claims 6 to 15, wherein the controller or system is configured to adjust one or more operating parameters of the aerosol delivery system dependent on the voltage across or resistance of the aerosol generator.

17. A method of controlling an aerosol delivery system comprising a variable resistance component or circuit connected in series with an aerosol generator in use, the variable resistance component or circuit having a variable total resistance and forming a variable voltage divider for determining a voltage across the aerosol generator in use, the method comprising: a. adjusting the variable resistance for determining a voltage across the aerosol generator.

18. The method of claim 17, comprising setting the variable resistance depending on whether or not a voltage across the aerosol generator is being determined.

19. The method of claim 18, comprising: a. setting the variable resistance to a first, high resistance when determining a voltage across the aerosol generator; and b. setting the variable resistance to a second, low resistance when not determining a voltage across the aerosol generator.

20. A computer program product or computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the method of any of claims 17-19.