WO2015200454A1 - Sequential linear led system with low output ripple - Google Patents

Sequential linear led system with low output ripple Download PDF

Info

Publication number
WO2015200454A1
WO2015200454A1 PCT/US2015/037372 US2015037372W WO2015200454A1 WO 2015200454 A1 WO2015200454 A1 WO 2015200454A1 US 2015037372 W US2015037372 W US 2015037372W WO 2015200454 A1 WO2015200454 A1 WO 2015200454A1
Authority
WO
WIPO (PCT)
Prior art keywords
led
current
capacitor
led string
ancillary
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/US2015/037372
Other languages
French (fr)
Inventor
Scott Lynch
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.)
Microchip Technology Inc
Original Assignee
Microchip Technology Inc
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 Microchip Technology Inc filed Critical Microchip Technology Inc
Priority to TW104120795A priority Critical patent/TW201607377A/en
Publication of WO2015200454A1 publication Critical patent/WO2015200454A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • H05B45/395—Linear regulators
    • 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]
    • H05B45/40—Details of LED load circuits
    • H05B45/44—Details of LED load circuits with an active control inside an LED matrix
    • H05B45/48—Details of LED load circuits with an active control inside an LED matrix having LEDs organised in strings and incorporating parallel shunting devices
    • 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]
    • H05B45/40—Details of LED load circuits
    • H05B45/44—Details of LED load circuits with an active control inside an LED matrix
    • H05B45/46—Details of LED load circuits with an active control inside an LED matrix having LEDs disposed in parallel lines
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Definitions

  • a sequential linear light emitting diode (LED) driver with a low output ripple is disclosed.
  • Prior art LED system 100 comprises AC voltage source 110, bridge rectifier 120, and diode 130.
  • Prior art LED system 100 further comprises a plurality of LED strings, here shown as LED string 141, LED string 142, LED string 143, and LED string 144.
  • a current regulator is attached after each LED string, here shown as current regulator 151, current regulator 152, current regulator 153, current regulator 154, and current regulator 155. It is to be understood that prior art LED system 100 can comprise a greater or fewer number of LED strings and current regulators than what is shown.
  • LED string 141 As the voltage output of bridge rectifier 120 increases from 0V, LED string 141 is forward biased such that the LEDs in LED string 141 emit light and current is controlled by current regulator 151. When the voltage becomes sufficiently high, LED string 142 also will become forward biased such that the LEDs in both LED string 141 and LED string 142 emit light. At that point, current regulator 152 will cause current regulator 151 to shut down. As the voltage increases further, the same happens for the remaining LED strings and current regulators, until LED strings 141, 142, 143, and 144 are emitting light, current is drawn by current regulator 155, and current regulators 151, 152, 153, and 154 are turned off.
  • LED system 100 One drawback of prior art LED system 100 is that when the voltage provided by AC voltage source 110 approaches 0V, the total light output from all LED strings will be zero. That is, LED system 100 will stop emitting light, which results in a "strobing" or “ripple” effect. This is extremely undesirable from a user's point of view.
  • the present invention reduces or eliminates the strobing or ripple effect through the use of a fill capacitor that is charged by a current regulator.
  • Figure 1 depicts a prior art LED system.
  • Figure 2 depicts an embodiment of an LED system comprising a fill capacitor charged by a current regulator.
  • Figure 3 depicts another embodiment of an LED system comprising a fill capacitor charged by a current regulator.
  • LED system 200 is depicted.
  • LED system 200 comprises many of the same components in prior art LED system 100 shown in Figure 1.
  • LED system 200 further comprises fill capacitor 210, current regulator 220, LED string 230, and diodes 241, 242, 243, and 244.
  • LED string 230 is optional and does not need to be used. If used, LED string 230 could comprise one LED or multiple LEDs. Moreover, one or more additional LED strings could be added to LED string 230.
  • Current regulators 151, 152, 153, 154, and 155 are coupled to resistor 160, which in turn is coupled to ground. Thus, current regulators 151, 152, 153, 154, and 155 share a common path to ground.
  • fill capacitor 210 When the voltage output by bridge rectifier 120 approaches the zero crossings (the situation in which prior art LED system 100 would emit no light), the charge stored in fill capacitor can be used to power LED strings 141, 142, 143, and 144. Current will flow from ground through diode 242, LED string 230, diode 243, through fill capacitor 210 and into LED strings 141, 142, 143, and 144. The voltage provided by fill capacitor 210 will be at the peak voltage of fill capacitor 210. Thus, unlike in the prior art, LED strings 141, 142, 143, and 144 can continue to emit light even in periods when AC voltage source 110 is producing a voltage near 0 V. [0014] As fill capacitor 210 is discharged, its voltage will decrease.
  • LED strings 141, 142, 143, and 144 will stop conducting one-by-one, in reverse order starting with LED string 144.
  • LED string 144 will stop emitting light when the voltage of fill capacitor 210 drops below a certain level.
  • current regulator 155 will stop drawing current and will activate current regulator 154.
  • Current regulator 154 will then draw current until LED string 143 stops emitting light, at which point current regulator 154 will stop drawing current and will activate current regulator 153. This process continues until only LED string 141 and current regulator 151 are active, although at some point the voltage from bridge rectifier 120 will exceed the voltage being provided by fill capacitor 210.
  • LED system 300 comprises many of the same components as LED system 200.
  • LED system 300 also comprises LED string 310, diode 130, current regulator 320, and control circuit 350.
  • Control circuit 350 controls current regulators 151, 152, 153, 154, 155, 220, and 320.
  • the purpose of LED string 210 and current regulator 320 is to reduce the total harmonic distortion (THD) of the system and to maintain total light output over time.
  • TDD total harmonic distortion
  • LED system 200 and LED system 300 minimize or eliminate the output ripple and "strobe effect" of prior art LED system 100. In addition, a greater power factor is achieved. LED system 300 further reduces the THD of the system.

Landscapes

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

Abstract

A sequential linear light emitting diode (LED) system with a low output ripple is disclosed. In one embodiment, the a sequential linear LED system comprises a bridge rectifier for generating a DC voltage, a diode for receiving the DC voltage, a capacitor coupled to the diode, a current regulator coupled to the capacitor for controlling the charging of the capacitor, and a plurality of segments coupled to the diode, each segment comprising an LED string and current regulator.

Description

SEQUENTIAL LINEAR LED SYSTEM WITH LOW OUTPUT RIPPLE
CROSS REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority to U.S. Provisional Application No. 62/018,531, filed on June 27, 2014, and titled "Sequential Linear LED System with Low Output Ripple," which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] A sequential linear light emitting diode (LED) driver with a low output ripple is disclosed.
BACKGROUND OF THE INVENTION
[0003] With reference to Figure 1, prior art LED system 100 is depicted. Prior art LED system 100 comprises AC voltage source 110, bridge rectifier 120, and diode 130. Prior art LED system 100 further comprises a plurality of LED strings, here shown as LED string 141, LED string 142, LED string 143, and LED string 144. A current regulator is attached after each LED string, here shown as current regulator 151, current regulator 152, current regulator 153, current regulator 154, and current regulator 155. It is to be understood that prior art LED system 100 can comprise a greater or fewer number of LED strings and current regulators than what is shown.
[0004] As the voltage output of bridge rectifier 120 increases from 0V, LED string 141 is forward biased such that the LEDs in LED string 141 emit light and current is controlled by current regulator 151. When the voltage becomes sufficiently high, LED string 142 also will become forward biased such that the LEDs in both LED string 141 and LED string 142 emit light. At that point, current regulator 152 will cause current regulator 151 to shut down. As the voltage increases further, the same happens for the remaining LED strings and current regulators, until LED strings 141, 142, 143, and 144 are emitting light, current is drawn by current regulator 155, and current regulators 151, 152, 153, and 154 are turned off.
[0005] One drawback of prior art LED system 100 is that when the voltage provided by AC voltage source 110 approaches 0V, the total light output from all LED strings will be zero. That is, LED system 100 will stop emitting light, which results in a "strobing" or "ripple" effect. This is extremely undesirable from a user's point of view.
[0006] What is needed is an improved LED system with a decreased strobing or ripple effect.
SUMMARY OF THE INVENTION
[0007] The present invention reduces or eliminates the strobing or ripple effect through the use of a fill capacitor that is charged by a current regulator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 depicts a prior art LED system.
[0009] Figure 2 depicts an embodiment of an LED system comprising a fill capacitor charged by a current regulator.
[0010] Figure 3 depicts another embodiment of an LED system comprising a fill capacitor charged by a current regulator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] With reference to Figure 2, LED system 200 is depicted. LED system 200 comprises many of the same components in prior art LED system 100 shown in Figure 1. LED system 200 further comprises fill capacitor 210, current regulator 220, LED string 230, and diodes 241, 242, 243, and 244. LED string 230 is optional and does not need to be used. If used, LED string 230 could comprise one LED or multiple LEDs. Moreover, one or more additional LED strings could be added to LED string 230. Current regulators 151, 152, 153, 154, and 155 are coupled to resistor 160, which in turn is coupled to ground. Thus, current regulators 151, 152, 153, 154, and 155 share a common path to ground.
[0012] During operation, as the voltage from bridge rectifier 120 increases from 0V, current will flow into fill capacitor 210 and through diode 241, through LED string 230, through diode 244, and through current regulator 220. Current also will flow into the lower circuit, starting with LED string 141 and current regulator 151. By controlling current regulator 220 and current regulators 151, 152, 153, 154, and 155 using control circuit 250, the system can allocate current between charging fill capacitor 210 and providing power to LED strings 141, 142, 143, and 144 and can maximize the power factor of LED system 200 (such that voltage and current usage are in phase with one another). Thus, current regulator 220 can be used to control the charging of fill capacitor to maintain a high input power factor.
[0013] When the voltage output by bridge rectifier 120 approaches the zero crossings (the situation in which prior art LED system 100 would emit no light), the charge stored in fill capacitor can be used to power LED strings 141, 142, 143, and 144. Current will flow from ground through diode 242, LED string 230, diode 243, through fill capacitor 210 and into LED strings 141, 142, 143, and 144. The voltage provided by fill capacitor 210 will be at the peak voltage of fill capacitor 210. Thus, unlike in the prior art, LED strings 141, 142, 143, and 144 can continue to emit light even in periods when AC voltage source 110 is producing a voltage near 0 V. [0014] As fill capacitor 210 is discharged, its voltage will decrease. As the voltage of fill capacitor 210 decreases, LED strings 141, 142, 143, and 144 will stop conducting one-by-one, in reverse order starting with LED string 144. Thus, LED string 144 will stop emitting light when the voltage of fill capacitor 210 drops below a certain level. At that point, current regulator 155 will stop drawing current and will activate current regulator 154. Current regulator 154 will then draw current until LED string 143 stops emitting light, at which point current regulator 154 will stop drawing current and will activate current regulator 153. This process continues until only LED string 141 and current regulator 151 are active, although at some point the voltage from bridge rectifier 120 will exceed the voltage being provided by fill capacitor 210.
[0015] With reference to Figure 3, another embodiment is depicted. LED system 300 comprises many of the same components as LED system 200. LED system 300 also comprises LED string 310, diode 130, current regulator 320, and control circuit 350. Control circuit 350 controls current regulators 151, 152, 153, 154, 155, 220, and 320. The purpose of LED string 210 and current regulator 320 is to reduce the total harmonic distortion (THD) of the system and to maintain total light output over time.
[0016] LED system 200 and LED system 300 minimize or eliminate the output ripple and "strobe effect" of prior art LED system 100. In addition, a greater power factor is achieved. LED system 300 further reduces the THD of the system.

Claims

What Is Claimed Is:
1. A light emitting diode (LED) system comprising:
an alternating current voltage source;
a bridge rectifier coupled to the alternating current voltage source;
a plurality of LED strings coupled to an output of the bridge rectifier, each of the plurality of LED strings comprising one or more LEDs;
a plurality of current regulators, each of the plurality of current regulators coupled to one of the plurality of LED strings to control current through that LED string;
a capacitor coupled to the output of the bridge rectifier and to an ancillary current regulator; wherein when the output of the bridge rectifier is reverse-biased, the capacitor provides a positive voltage to the plurality of LED strings to initially cause one or more the plurality of LED strings to emit light after the output of the bridge rectifier becomes reverse-biased.
2. The system of claim 2, further comprising a control circuit for controlling the plurality of current regulators and the ancillary current regulator coupled to the capacitor to allocate current between charging the capacitor and providing power to the plurality of LED strings.
3. The system of claim 2, wherein the control circuit allocates current between charging the capacitor and providing power to the plurality of LED strings to maintain a high input power factor.
4. The system of claim 1, further comprising a resistor coupled to each of the plurality of current regulators to provide a common path to ground.
5. The system of claim 1, further comprising an ancillary LED string comprising one or more LEDs coupled between the capacitor and the ancillary current regulator.
6. The system of claim 5, further comprising a diode coupled between the capacitor and the ancillary LED string and a diode between the ancillary LED string and the ancillary current regulator.
7. The system of claim 6, further comprising a diode coupled between ground and the ancillary LED string and another diode coupled between the capacitor and ancillary LED string.
8. The system of claim 7, wherein when the main diode is reverse-biased, current initially flows from ground through a diode, the ancillary LED string, a diode, the capacitor, and one or more of the plurality of LED strings.
9. The system of claim 1, further comprising a second ancillary LED string coupled between the bridge rectifier and main diode.
10. The system of claim 9, further comprising a current regulator coupled to the second ancillary LED string and to the control circuit.
11. A method of operating a light emitting diode (LED) system comprising:
concurrently provide current to a capacitor and a first LED string, the first LED string comprising one or more LEDs;
while an output of a bridge rectifier is still forward biased, providing current to a first LED string and one or more additional LED strings, each of the one or more additional LED strings comprising one or more LEDs;
reverse biasing the output of the bridge rectifier and providing current from the capacitor to the first LED string and the one or more additional LED strings;
when the output of the bridge rectifier is still reverse biased, providing current from the capacitor only to the first LED string
12. The method of claim 11, further comprising: allocating, by a control circuit, current between charging the capacitor and providing power to the first LED string and the one or more additional LED strings.
13. The method of claim 12, wherein the allocating step maintains a high input power factor.
14. The method of claim 11, wherein a resistor coupled to the first LED string and the one or more additional LED strings provides a common path to ground.
15. The method of claim 11, further comprising:
when the output of the bridge rectifier is forward biased, providing current to an ancillary LED string comprising one or more LEDs coupled to the capacitor.
16. The method of claim 15, wherein a diode is coupled between the capacitor and the ancillary LED string.
17. The method of claim 16, wherein a diode is coupled between ground and the ancillary LED string and a diode is coupled between the capacitor and the ancillary LED string.
18. The method of claim 17, further comprising:
when the output of the bridge rectifier is reverse-biased, providing current from ground through a diode, the ancillary LED string, a diode, the capacitor, and at least the first LED string.
19. The method of claim 11, further comprising:
providing current to a second ancillary LED string coupled between the bridge rectifier and main diode.
20. The method of claim 19, further comprising:
allocating, by a control circuit, current between charging the capacitor and providing power to the first LED string, the one or more additional LED strings, and the second ancillary LED string.
PCT/US2015/037372 2014-06-27 2015-06-24 Sequential linear led system with low output ripple Ceased WO2015200454A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
TW104120795A TW201607377A (en) 2014-06-27 2015-06-26 Sequential linear LED system with low output ripple

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201462018531P 2014-06-27 2014-06-27
US62/018,531 2014-06-27
US14/748,175 2015-06-23
US14/748,175 US20150382414A1 (en) 2014-06-27 2015-06-23 Sequential Linear LED System With Low Output Ripple

Publications (1)

Publication Number Publication Date
WO2015200454A1 true WO2015200454A1 (en) 2015-12-30

Family

ID=54932125

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2015/037372 Ceased WO2015200454A1 (en) 2014-06-27 2015-06-24 Sequential linear led system with low output ripple

Country Status (3)

Country Link
US (1) US20150382414A1 (en)
TW (1) TW201607377A (en)
WO (1) WO2015200454A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107360647A (en) * 2017-07-20 2017-11-17 武汉尚智通科技有限公司 A kind of alternating current direct source connects the power supply of driving LED

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9883554B2 (en) * 2015-09-29 2018-01-30 Microchip Technology Inc. Commutation circuit for sequential linear LED drivers
US9730280B2 (en) * 2015-10-01 2017-08-08 Microchip Technology Inc. Ripple reduction circuit for sequential linear LED drivers
CN108811232B (en) * 2017-05-05 2020-04-07 东莞艾笛森光电有限公司 LED driver circuit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130200802A1 (en) * 2012-02-03 2013-08-08 Nichia Corporation Light-emitting diode driving apparatus
US20130313984A1 (en) * 2011-02-10 2013-11-28 Hubert Maiwald Actuating a Plurality of Series-Connected Luminous Elements

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7081722B1 (en) * 2005-02-04 2006-07-25 Kimlong Huynh Light emitting diode multiphase driver circuit and method
JP4657799B2 (en) * 2005-05-11 2011-03-23 株式会社リコー Light emitting diode drive circuit
US8384311B2 (en) * 2009-10-14 2013-02-26 Richard Landry Gray Light emitting diode selection circuit
RU2589734C2 (en) * 2011-03-28 2016-07-10 Конинклейке Филипс Н.В. Excitation device and method for excitation of load, in particular, light-emitting diodes
US8686651B2 (en) * 2011-04-13 2014-04-01 Supertex, Inc. Multiple stage sequential current regulator
KR101357916B1 (en) * 2012-08-06 2014-02-03 메를로랩 주식회사 Dimming system for led lighting device
US9041303B2 (en) * 2013-03-29 2015-05-26 Posco Led Company Ltd. AC LED lighting apparatus
PL222678B1 (en) * 2013-08-23 2016-08-31 Włodarczyk Władysław Igloo Three phase power supply and the LED diode system with three phase power supply
JP6512507B2 (en) * 2014-07-24 2019-05-15 パナソニックＩｐマネジメント株式会社 Lighting device, lighting device and lighting device
JP6501175B2 (en) * 2014-07-29 2019-04-17 パナソニックＩｐマネジメント株式会社 Lighting device, lighting device and lighting device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130313984A1 (en) * 2011-02-10 2013-11-28 Hubert Maiwald Actuating a Plurality of Series-Connected Luminous Elements
US20130200802A1 (en) * 2012-02-03 2013-08-08 Nichia Corporation Light-emitting diode driving apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107360647A (en) * 2017-07-20 2017-11-17 武汉尚智通科技有限公司 A kind of alternating current direct source connects the power supply of driving LED
CN107360647B (en) * 2017-07-20 2019-04-05 武汉尚智通科技有限公司 A kind of alternating current directly drives the power supply of LED light

Also Published As

Publication number Publication date
TW201607377A (en) 2016-02-16
US20150382414A1 (en) 2015-12-31

Similar Documents

Publication Publication Date Title
CN105230126B (en) LED drive circuit using doube bridge diode and the LED light device including it
US10080267B2 (en) Alternating current-driven light emitting element lighting apparatus
EP3148295A1 (en) Led illumination device using ac power
US10397998B2 (en) Driver circuit and method
US20150382414A1 (en) Sequential Linear LED System With Low Output Ripple
SA515360631B1 (en) Led driver circuit using flyback converter to reduce observable optical flicker by reducing rectified ac mains ripple
US8749164B2 (en) Illuminating apparatus capable of detecting power supply and method using the same
US20170099708A1 (en) Ripple reduction circuit for sequential linear led drivers
US20150280566A1 (en) Switch circuit for controlling supply of electrical energy to a load
CN102969911B (en) Power circuit and use the lighting device of this power circuit
US9693406B2 (en) Circuit for driving AC direct lighting apparatus and method therefor
US8030853B1 (en) Circuit and method for improving the performance of a light emitting diode (LED) driver
US20100309188A1 (en) Driver for a projection system
US20150008834A1 (en) Lossless forward voltage matching network for led drivers
KR20140133262A (en) Apparatus for driving light emitting diode
JP5214003B2 (en) Power supply device and lighting device
US10237931B2 (en) Regulated power supply voltage and triac hold-up current for a switching power converter
KR101537990B1 (en) LED Lighting Apparatus
KR20130107019A (en) System for lighting using light emitting diode
US20170127488A1 (en) Adaptive Power Balancing in LED Lamps
KR20130113169A (en) Apparatus for driving light emitting diode
CN105050260B (en) LED illumination system
US20150216003A1 (en) Anti-Flickering LED Lighting System
CN105282899B (en) Driving circuit of light emitting diode with low flicker and high power factor
EP4691182A1 (en) A tapped linear led driving arrangement

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15738531

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15738531

Country of ref document: EP

Kind code of ref document: A1