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WO2007141741A1 - Circuits pour effectuer une gradation de lumière de dispositifs d'éclairage à diodes led - Google Patents

Circuits pour effectuer une gradation de lumière de dispositifs d'éclairage à diodes led Download PDF

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Publication number
WO2007141741A1
WO2007141741A1 PCT/IB2007/052131 IB2007052131W WO2007141741A1 WO 2007141741 A1 WO2007141741 A1 WO 2007141741A1 IB 2007052131 W IB2007052131 W IB 2007052131W WO 2007141741 A1 WO2007141741 A1 WO 2007141741A1
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WO
WIPO (PCT)
Prior art keywords
led
current
switch
circuitry
leds
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/IB2007/052131
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English (en)
Inventor
Matthieu M. J. Verstraete
Alexandre P. GÉBLEUX
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Publication of WO2007141741A1 publication Critical patent/WO2007141741A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/375—Switched mode power supply [SMPS] using buck topology

Definitions

  • This invention relates to a current supply circuitry for dimming illumination devices comprising LEDs as light sources. More particular, it relates to a current supply circuitry comprising at least one LED, at least one inductive reactance acting as an energy storage choke, a free running current path and a switch for switching between a charging and a discharging process occurring in the storage choke.
  • a current supply circuitry of the kind set forth is known per se, for instance from US2006/ 0072324.
  • This document discloses a LED driving semiconductor circuit including a first input terminal connected to a LED, a switching device block having a first FET and a first switching device. Furthermore, the circuit includes a reference voltage terminal which is connected to the first FET and outputs a reference voltage and a start/stop circuit which outputs a start signal when the reference voltage is equal to or larger than a predetermined value and outputs a stop signal when the reference voltage is less then the predetermined value.
  • the circuit includes a current detection circuit which detects the current flow through the first switching device and a control circuit which controls ON/ OFF of the first switching device intermittently at the predetermined frequency based on the output signal of the start/stop circuit so that the constant current flows through the LED.
  • a drawback of the circuitry disclosed in US2006/ 0072324 is that the current through the LEDs is continuous and modulated down to low levels when a high dimming of the LEDs is required. As a consequence the light generating efficiency of the LEDs is low, especially for high power LEDs.
  • a current supply circuitry for dimming illumination devices comprising LEDs as light sources having a high efficiency in generating light, even when low light levels (equivalent to high dimming levels) are required.
  • This object is achieved with the a current supply circuitry according to the invention as defined in claim 1.
  • the a current supply circuitry according to the invention characterized in that the circuitry comprises control means arranged to change the current supplied to the LED from a continuous conduction mode to a discontinuous conduction mode at an adjustable dimming level of the LED.
  • the invention provides a circuitry capable of supplying a current to the LED(s) in adequacy with the LED specifications even at very high dimming levels. At these levels the circuitry switches over to the discontinuous conduction mode.
  • control means is arranged to turn the switch off at a predetermined current I pea k through the LED and to turn the switch on after a controllable delay time td elay .
  • the current I pea k is the rated or nominal design current of the LED.
  • the LED dimming level is arranged to be determined by the delay time tdeiay-
  • the delay time tdeiay between the point where the current through the LEDs reaches I pea k(and the switch is turned off) to the point where the switch is turned back on determines the average light output of the LED.
  • Fig. 1 shows a circuitry according to the invention
  • Fig. 2 shows the current flow in an embodiment of the invention
  • Fig. 3 shows the current through the LEDs as a function of time for different delay times
  • Fig. 4 shows a detail of an embodiment of the invention
  • Fig. 5 shows details of two different embodiments of the invention
  • Fig. 6 shows a detail of an embodiment of the invention
  • Fig. 7 shows an embodiment for controlling the delay time tdeiay
  • Fig. 8 shows another embodiment for controlling the delay time tdeiay
  • Fig. 1 is the schematic of a circuit that has been implemented and tested in a real LED application. Some useful but not essential electronics components have been removed for a better understanding.
  • the right part of the design is dedicated to the power flux, the left part of the design is dedicated to the control means 50. How does the power flux stage work ?
  • the functioning mode of the power stage is similar to a BUCK topology in which the output capacitor would have been removed.
  • the main components of this stage are :
  • DELl ... DELN Light Emitting Diodes 10 (load)
  • Tl switch 40 - a transistor working in commutation
  • Ll a 'smoothing' self working as a storage choke
  • Dl a free-wheel diode working as a free running current path 30 (switch with automatic commutation)
  • RS 1 resistor to measure current (used to detect peak current)
  • RS2 resistor to measure current (used to measure average current in the load)
  • V PO WER voltage supply
  • V CTR l and V CTR 2 control voltages (set points)
  • the power transfer to the LEDs 10 is done in 2 phases (see Fig. 2): (i) Phase « A » - "main conduction" - the switch 40 (transistor Tl) is conductive, the energy is supplied by the power supply V POWER and (ii) Phase « B » - « relaxation » - the choke 20 (self Ll) gives back its energy through the free-wheel diode, working as a free running current path 30.
  • the switch 40 When the switch 40 is conductive (phase « A »), the current through the LED 10 increases linearly. When the current reaches the predetermined "I pea k" value, the switch 40 is opened (controlled by the control means 50 comprising a microcontroller) for an adjustable time tdeiay (also controlled by the microcontroller). When the switch 40 goes to OFF state (phase « B »), the current in the load (i.e. through the LEDs 10) is decreasing linearly.
  • the light flux emitted by the LEDs 10 is proportional to the average current that goes through the LEDs.
  • Fig. 3 shows that it is possible to obtain a particular flux by spacing out the current pulses.
  • the low limit of the period (the high limit of tdeiay) is determined by the retinal perception, so few hundreds hertz, while the high limit (the low limit of tdeiay) is linked to the technology, its choice is a compromise between economical and EMC constraints, for example 140 kHz, would give a suitable dynamic range for flux variation.
  • Fig. 3 shows that for (very) low flux, the current through the LEDs - and thus their light output - is pulsed (Figs. 3.1, 3.2 and 3.3), whereas it becomes continuous for high flux (Figs. 3.4 and 3.5).
  • the flux is controlled by only one timing parameter tdeiay.
  • the spectrum analysis obtained would come from the triangular component of the waveform.
  • the current solution is not similar at all to a "switching supply" (with its own switching frequency), which would be itself modulated by a second frequency (PWM mode).
  • PWM mode a second frequency
  • the flux variation is a continuous process of increasing one (only) commutation frequency, to get in the load (LED 10) the suitable average current by pulse shapes in adequacy with the LED specifications.
  • the power stage looks like BUCK supply topology, for which the output capacitor would have been removed. Switching from one conduction mode to the other, based on a current peak detection looks close to the functioning mode of FLYBACK supply, called "currents mode". Based on tdeiay and I pea k it is possible to use and adapt a wide range of regulators from the market to the topology described.
  • the schematic in Fig. 4 shows a well-known topology.
  • a significant advantage compared to Fig. 1 is to use only one resistor ( « RS ») to measure both peak current and average current.
  • 2 resistors where used for practical reason.
  • An important parameter to take into account in the choice of the topology to implement is the supply voltage. With the topology presented in Fig. 1, the switch is easily controlled related to zero volt, whereas in Fig. 4 it requires a voltage translation. Actually, it is possible to create many different implementations by simply permuting components.
  • the choke 20 (self Ll) is on the switch 40 side (Fig. 5A), or on the supply side (Fig. 5B). Those permutations can result in different behaviors of the circuit.
  • Fig. 3 shows that it is possible to have an important flux variation, providing that the power stage can work in both continuous conduction mode and discontinuous conduction mode.
  • the control means 50 for the control of the flux generally comprises a microcontroller that receives orders (from a controller) for flux variation. Those orders are sometimes fast. It is therefore necessary to have a way of controlling that handles the switch 40 from one conduction mode to the other, that is also able to quickly reach the required flux level, while furthermore stabilizes quickly when that level has been reached. Going from one conduction mode to the other is very difficult. Controlling the flux of the average current requires a filter to smooth the measuring of the current, which means a time constant that is not compatible with the required response time. The solution is to modulate the flux by controlling the delay time tdeiay between the time point where the current reaches its peak value and the next transition of the switch to ON state.
  • the control voltages V CTR l and C CTR 2 are supplied by a microcontroller.
  • the V CTR 2 voltage determines the I pea k current
  • the V_CTR_1 voltage determines the delay time tdeiay
  • UlOl works like a flip-flop, it is based on a cheap timer very well known in electronics.
  • the switch 40 When the switch 40 is ON, the current through the LEDs 10 is increasing linearly.
  • the comparator UlOOA switches the OUT output of UlOl to zero, and opens the switch 40.
  • the output of the flip-flop controls simultaneously the transistor (TlOl), keeping the capacitor ClOO unloaded.
  • a delay time td elay There are many ways to generate a delay time td elay .
  • the advantage of the method presented in Fig. 7 is its cost effectiveness.
  • One of the advantages of this principle is its possibility to evolve to digital implementation.
  • the delay time tdeiay can of course be obtained accurately by a counter in a FPGA or similar device.
  • RS2 used to measure the average current in the LEDs 10, is mainly used during calibration of the product.
  • the non-linearity of the transfer- function complicates the determination of the functioning to control the current.
  • the measurement of the current through RS2 complicates the design when the supply voltage goes over few tens of voltage.
  • the values are choosen and fixed according to the voltage values and the maximum current in the loads (LEDs 10). Knowing those values and the variation curve, it is possible to estimate the control values (I pe ak and tdeiay) to reach the fitting current and voltage for the load (LEDs 10). The possibility to determine the functioning point without direct measurement of the current simplifies the circuit, and therefore reduces the costs.
  • the solution consists on having the possibility in the circuit to detect the value of tdeiay (Ipeak is fixed by the LEDs 10) for which the system switches from discontinuous conduction mode to continuous conduction mode at a predetermined dimming level of the LEDs 10.
  • the value of tdeiay only depends on the voltage at the terminals of the LEDs 10. By knowing the LEDs voltage it is possible to estimate the tdeiay value to reach the desired current (the voltage can be very different from one LED 10 to the other, but is very stable in time).
  • Fig. 8 shows the simplicity to implement the solution. Just after that the switch 40 is in conduction mode, the voltage at the terminals of the resistor of I max measurement is compared to a value close to zero. The result of the comparison makes possible to estimate the conduction mode. The resistor (RS2 Fig. 1) to measure the average current and the associated translators are removed.

Landscapes

  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

L'invention concerne des circuits d'alimentation en courant (1) destinés à au moins une diode LED (10), comprenant au moins une réactance inductive reliée comme bobine d'arrêt de stockage (20) en série avec la diode LED (10), une ligne (30) de courant non synchronisé, reliée en parallèle à la connexion en série de la diode LED (10) et de la bobine d'arrêt de stockage (20), un interrupteur (40) permettant d'effectuer une commutation entre un processus de charge et un processus de décharge se produisant dans la bobine d'arrêt de stockage (20). Les circuits d'alimentation en courant (1) sont caractérisés en ce que les circuits comprennent un moyen de commande (50) disposé pour modifier le courant appliqué à la diode LED (10) depuis un mode de conduction continue jusqu'à un mode de conduction discontinue avec un niveau réglable de gradation de lumière de la diode LED (10).
PCT/IB2007/052131 2006-06-08 2007-06-06 Circuits pour effectuer une gradation de lumière de dispositifs d'éclairage à diodes led Ceased WO2007141741A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP06300568 2006-06-08
EP06300568.0 2006-06-08

Publications (1)

Publication Number Publication Date
WO2007141741A1 true WO2007141741A1 (fr) 2007-12-13

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Application Number Title Priority Date Filing Date
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WO (1) WO2007141741A1 (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010039588A3 (fr) * 2008-09-30 2010-05-27 Cirrus Logic, Inc. Source de courant constant réglable à fonctionnement en mode de conduction continue ("ccm") et en mode de conduction discontinue ("dcm")
WO2010128845A3 (fr) * 2009-05-04 2011-03-31 Eldolab Holding B.V. Unité de commande pour un ensemble del et un système d'éclairage
WO2011057050A1 (fr) * 2009-11-06 2011-05-12 Abl Ip Holding Llc Source d'alimentation en énergie électrique efficace pour système d'éclairage à semi-conducteur
WO2011076898A1 (fr) * 2009-12-23 2011-06-30 Tridonic Ag Circuit permettant de faire fonctionner des diodes électroluminescentes (del)
EP2683222A1 (fr) * 2012-07-05 2014-01-08 Panasonic Corporation Dispositif d'éclairage à DEL et appareil d'éclairage l'utilisant
US8643284B2 (en) 2008-08-15 2014-02-04 Eldolab Holdings B.V. LED assembly driving circuit
CN103597722A (zh) * 2011-04-29 2014-02-19 赤多尼科两合股份有限公司 具有功率因数校正电路的用于照明用具的操作设备
CN103687185A (zh) * 2012-09-07 2014-03-26 松下电器产业株式会社 固体发光元件驱动装置、照明系统和照明器具
EP2512208A3 (fr) * 2011-04-13 2014-05-14 Panasonic Corporation Dispositif d'éclairage de source lumineuse solide et accessoire d'éclairage l'utilisant
US8816604B2 (en) 2012-08-03 2014-08-26 Ge Lighting Solutions, Llc. Dimming control method and apparatus for LED light source
WO2015059204A3 (fr) * 2013-10-25 2015-07-02 Osram Opto Semiconductors Gmbh Circuiterie, système de diodes électroluminescentes et procédé de commande d'un composant optoélectronique
US9155150B2 (en) 2011-09-19 2015-10-06 Koninklijke Philips N.V. LED driver operating in different modes
US9820347B2 (en) 2008-06-24 2017-11-14 Eldolab Holding B.V. Control unit for a LED assembly and lighting system
DE112014002232B4 (de) 2013-04-30 2024-04-18 Tridonic Gmbh & Co Kg Betriebsschaltung für LED

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Publication number Priority date Publication date Assignee Title
FR2786652A1 (fr) * 1998-11-30 2000-06-02 St Microelectronics Sa Alimentation d'une diode electroluminescente sur le secteur
WO2004057921A1 (fr) * 2002-12-19 2004-07-08 Koninklijke Philips Electronics N.V. Ensemble d'alimentation pour module d'eclairage a diodes electroluminescentes
US20050218838A1 (en) * 2004-03-15 2005-10-06 Color Kinetics Incorporated LED-based lighting network power control methods and apparatus
US20060072324A1 (en) * 2004-10-01 2006-04-06 Yoshiaki Hachiya LED driving semiconductor circuit and LED driving apparatus including the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2786652A1 (fr) * 1998-11-30 2000-06-02 St Microelectronics Sa Alimentation d'une diode electroluminescente sur le secteur
WO2004057921A1 (fr) * 2002-12-19 2004-07-08 Koninklijke Philips Electronics N.V. Ensemble d'alimentation pour module d'eclairage a diodes electroluminescentes
US20050218838A1 (en) * 2004-03-15 2005-10-06 Color Kinetics Incorporated LED-based lighting network power control methods and apparatus
US20060072324A1 (en) * 2004-10-01 2006-04-06 Yoshiaki Hachiya LED driving semiconductor circuit and LED driving apparatus including the same

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10045408B2 (en) 2008-06-24 2018-08-07 Eldolab Holding B.V. Control unit for a LED assembly and lighting system
US9820347B2 (en) 2008-06-24 2017-11-14 Eldolab Holding B.V. Control unit for a LED assembly and lighting system
US8643284B2 (en) 2008-08-15 2014-02-04 Eldolab Holdings B.V. LED assembly driving circuit
CN102232264B (zh) * 2008-09-30 2015-07-08 美国思睿逻辑有限公司 具有连续传导模式(ccm)和不连续传导模式(dcm)操作的可调恒流源
WO2010039588A3 (fr) * 2008-09-30 2010-05-27 Cirrus Logic, Inc. Source de courant constant réglable à fonctionnement en mode de conduction continue ("ccm") et en mode de conduction discontinue ("dcm")
GB2475668A (en) * 2008-09-30 2011-05-25 Cirrus Logic Inc Adjustable constant current source with continuous conduction mode ("CCM") and discontinuous conduction mode ("DCM") operation
GB2475668B (en) * 2008-09-30 2012-12-19 Cirrus Logic Inc Adjustable constant current source with continuous conduction mode ("CCM") and discontinuous conduction mode ("DCM") operation
US8179110B2 (en) * 2008-09-30 2012-05-15 Cirrus Logic Inc. Adjustable constant current source with continuous conduction mode (“CCM”) and discontinuous conduction mode (“DCM”) operation
CN102461332A (zh) * 2009-05-04 2012-05-16 艾杜雷控股有限公司 用于led组件的控制单元以及照明系统
US20120104974A1 (en) * 2009-05-04 2012-05-03 Eldolab Holding B.V. Control unit for a led assembly and lighting system
US10390398B2 (en) 2009-05-04 2019-08-20 Eldolab Holding B.V. Control unit for a LED assembly and lighting system
US9629212B2 (en) 2009-05-04 2017-04-18 Eldolab Holding B.V. Control unit for a LED assembly and lighting system
WO2010128845A3 (fr) * 2009-05-04 2011-03-31 Eldolab Holding B.V. Unité de commande pour un ensemble del et un système d'éclairage
CN102461332B (zh) * 2009-05-04 2015-07-22 艾杜雷控股有限公司 用于led组件的控制单元以及照明系统
US8519634B2 (en) 2009-11-06 2013-08-27 Abl Ip Holding Llc Efficient power supply for solid state lighting system
WO2011057050A1 (fr) * 2009-11-06 2011-05-12 Abl Ip Holding Llc Source d'alimentation en énergie électrique efficace pour système d'éclairage à semi-conducteur
CN102812779B (zh) * 2009-12-23 2016-05-25 特里多尼克股份有限公司 用于操作发光二极管（led）的电路
DE112010004983B4 (de) 2009-12-23 2024-04-18 Tridonic Ag Schaltung für den Betrieb von Leuchtdioden (LEDs)
WO2011076898A1 (fr) * 2009-12-23 2011-06-30 Tridonic Ag Circuit permettant de faire fonctionner des diodes électroluminescentes (del)
EP2341760A1 (fr) * 2009-12-23 2011-07-06 Tridonic AG Circuit pour le fonctionnement de diodes électroluminescentes (DEL)
CN102812779A (zh) * 2009-12-23 2012-12-05 特里多尼克股份有限公司 用于操作发光二极管（led）的电路
US8872444B2 (en) 2011-04-13 2014-10-28 Panasonic Corporation Lighting device for solid-state light source and illumination apparatus including same
EP2512208A3 (fr) * 2011-04-13 2014-05-14 Panasonic Corporation Dispositif d'éclairage de source lumineuse solide et accessoire d'éclairage l'utilisant
CN103597722B (zh) * 2011-04-29 2016-01-20 赤多尼科两合股份有限公司 具有功率因数校正电路的用于照明用具的操作设备
CN103597722A (zh) * 2011-04-29 2014-02-19 赤多尼科两合股份有限公司 具有功率因数校正电路的用于照明用具的操作设备
US9155150B2 (en) 2011-09-19 2015-10-06 Koninklijke Philips N.V. LED driver operating in different modes
CN103533704A (zh) * 2012-07-05 2014-01-22 松下电器产业株式会社 Led点亮装置及使用该装置的照明设备
US9167642B2 (en) 2012-07-05 2015-10-20 Panasonic Intellectual Property Management Co., Ltd. LED lighting device and illuminating apparatus using the same
EP2683222A1 (fr) * 2012-07-05 2014-01-08 Panasonic Corporation Dispositif d'éclairage à DEL et appareil d'éclairage l'utilisant
CN103533704B (zh) * 2012-07-05 2015-07-29 松下电器产业株式会社 Led点亮装置及使用该装置的照明设备
US8816604B2 (en) 2012-08-03 2014-08-26 Ge Lighting Solutions, Llc. Dimming control method and apparatus for LED light source
CN103687185B (zh) * 2012-09-07 2016-08-10 松下知识产权经营株式会社 固体发光元件驱动装置、照明系统和照明器具
CN103687185A (zh) * 2012-09-07 2014-03-26 松下电器产业株式会社 固体发光元件驱动装置、照明系统和照明器具
DE112014002232B4 (de) 2013-04-30 2024-04-18 Tridonic Gmbh & Co Kg Betriebsschaltung für LED
CN105659699A (zh) * 2013-10-25 2016-06-08 奥斯兰姆奥普托半导体有限责任公司 电路布置、发光二极管组装以及用于激励光电组件的方法
CN105659699B (zh) * 2013-10-25 2018-07-17 奥斯兰姆奥普托半导体有限责任公司 电路布置、发光二极管组装以及用于激励光电组件的方法
US10236987B2 (en) 2013-10-25 2019-03-19 Osram Opto Semiconductors Gmbh Circuit arrangement, light-emitting diode assembly, and method of actuating an optoelectronic component
WO2015059204A3 (fr) * 2013-10-25 2015-07-02 Osram Opto Semiconductors Gmbh Circuiterie, système de diodes électroluminescentes et procédé de commande d'un composant optoélectronique

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