CN104254182A - LED (light emitting diode) driving circuit - Google Patents

LED (light emitting diode) driving circuit Download PDF

Info

Publication number
CN104254182A
CN104254182A CN201410475354.1A CN201410475354A CN104254182A CN 104254182 A CN104254182 A CN 104254182A CN 201410475354 A CN201410475354 A CN 201410475354A CN 104254182 A CN104254182 A CN 104254182A
Authority
CN
China
Prior art keywords
led array
circuit
led
transistor
operational amplifier
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.)
Granted
Application number
CN201410475354.1A
Other languages
Chinese (zh)
Other versions
CN104254182B (en
Inventor
吕坚
阙隆成
吴传福
吕静
周云
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.)
University of Electronic Science and Technology of China
Original Assignee
University of Electronic Science and Technology of China
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 University of Electronic Science and Technology of China filed Critical University of Electronic Science and Technology of China
Priority to CN201410475354.1A priority Critical patent/CN104254182B/en
Publication of CN104254182A publication Critical patent/CN104254182A/en
Application granted granted Critical
Publication of CN104254182B publication Critical patent/CN104254182B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The embodiment of the invention discloses an LED (light emitting diode) driving circuit, which comprises a driving circuit and a multi-channel LED array circuit, wherein the multi-channel LED array circuit comprises at least two LED array branches, and each LED array branch comprises a voltage follower and is connected with the error input end M of the driving circuit through the corresponding voltage follower. According to the circuit provided by the embodiment of the invention, the voltage follower is added among the LED array branches. The luminance of each line of LEDs is different, i.e., the current Ii passing through each line is different, but the voltage follower absorbs and compensates differential current when each channel works, so that the positive input Di of each LED array branch can be enabled to be respectively adjusted, and the voltage of the Mi part of each channel can maintain consistency, so the independent adjustment of each channel is realized, the feasibility of the circuit is improved, and the efficiency of the circuit is greatly improved.

Description

A kind of LED drive circuit
?
Technical field
The present invention relates to LED Driving technique field, especially relate to a kind of LED drive circuit.
 
Background technology
LED, due to environmental protection, the many merits such as the life-span is long, photoelectric efficiency is high, is able to fast development in every profession and trade in recent years.Along with LED luminous efficiency improves constantly, price reduces gradually, and the developmental research of high-power super bright white light LEDs becomes main direction.LED multi-path throws light in occasions such as being just applied in street, tunnel, subway simultaneously, receives extensive concern in the world.Therefore, the drive circuit design of great power LED also becomes focus.
Divide according to the connected mode of load, the type of LED drive circuit can be divided into: 1. tandem type; 2. parallel connection type; 3. the connected mode such as Serial-Parallel Type.In all connected modes, be all a series of combinations of basic series, parallel mode, so can analyze according to the relation of series connection or parallel connection the analysis of corresponding circuit.
Being connected in series is the negative pole positive pole of each LED being met next LED, connects bunchiness, generally should access current-limiting resistance R with this.This connected mode can realize by the electric current of each LED equal, but when one of them or several LED open circuit, then whole string LED can daughter-in-law go out.So this kind of method of attachment reliability is not high.
Be connected in parallel is the positive pole of multiple LED and positive pole, negative pole and negative pole are together in parallel.This connected mode can ensure that the operating voltage of each LED is the same, but because characterisitic parameter also exists difference between each LED component, conducting voltage VF is inconsistent, then can be inconsistent by the electric current of each LED.The poor LED of heat dispersion can reduce along with the rising conducting voltage of temperature, and cause the rising of On current If, the rising of If then can cause the aggravation of junction temperature to rise, and so forms positive feedback, finally causes burning of LED.Therefore form directly in parallel is not generally adopted.If desired LED parallel connection then should consider the impact of the factor such as device and environment on circuit, and joins to reduce LED by the probability burnt by suitable resistance and each LED strip.
String also Hybrid connections is first connected by multiple LED to compose in parallel luminescence component afterwards.For the LED on a branch road, if cause one or more LED on this branch road to lose efficacy because of the difference of device and service condition, then the operating current of this paths of LEDs only can be affected, relatively little on the impact of whole assembly.And each paths of LEDs can be regulated respectively according to circuit structure.Therefore the luminescence component reliability of this kind of connected mode is higher, and comparatively large to the selection range of individual devices, and the brightness of whole luminescence component is also relatively uniform.When Working Environments changes greatly, this kind of connected mode is best selection, and current this connected mode is widely used in a large amount of illumination example.
Divide according to the topological structure of circuit, LED drive circuit can be divided into linear structure, capacitance switch structure and inductance type construction of switch.Linear stable in linear structure mainly comprises low pressure pressurizer (LDO, Low Drop-Out) this circuit structure, and this circuit can only realize step-down driving and efficiency is very low under certain operating conditions.Charge pump (Charge Pump) in capacitance switch structure is also referred to as switched capacitor DC/ DC converter, and charge pump circuit utilizes the mode of Charger transfer to carry out work.Electric capacity is exactly the approach of Charger transfer, and it transfers to output electric charge from input, provides the electric current required for load.It both can make input voltage raise, reduce, and also can produce negative voltage.But power supply conversion efficiency increases along with input voltage and reduces, because the driver output voltage of charge pump construction is general lower, when load is multiple LED, the mode that these LED can only adopt connection in series-parallel to connect, traditional circuit can not regulate each bar LED branch current respectively.
 
Summary of the invention
An object of the present invention is to provide that a kind of efficiency is high, the LED drive circuit of flexibility and good stability, and the electric current of each LED channel in this circuit can independent regulation.
Technical scheme disclosed by the invention comprises:
Provide a kind of LED drive circuit, it is characterized in that, comprising: drive circuit, described drive circuit is used for providing drive current; Multi-channel LED array circuit, described multi-channel LED array circuit is connected to described drive circuit and receives described drive current, and described multi-channel LED array circuit comprises multiple LED, and described drive current drives described multiple LED to make described multiple LED luminous; Described multi-channel LED array circuit comprises at least two LED array branch roads, and described at least two LED array branch circuit parallel connections are connected between the first end A of described multi-channel LED array circuit and the second end N; Wherein: each described LED array branch road comprises voltage follower, described LED array branch road is connected to the error input M of described drive circuit by described voltage follower.
In one embodiment of the present of invention, described drive circuit comprises power vd D, the first transistor NM a, transistor seconds NM b, inverter, inductance, error amplifier and comparator, wherein: one end of described inductance is connected to the first end A of described multi-channel LED array circuit, and the other end is connected to described the first transistor NM asource electrode and described transistor seconds NM bdrain electrode; Described transistor seconds NM bsource electrode be connected to the described second end N of described multi-channel LED array circuit; The inverting input of described error amplifier is connected to the described error input M of described drive circuit, and the in-phase input end of described error amplifier is connected to reference voltage V rEF, the output of described error amplifier is connected to the inverting input of described comparator; The in-phase input end of described comparator is connected to saw-toothed wave generator; The output of described comparator is connected to described the first transistor NM agrid and the input of described inverter; The output of described inverter is connected to described transistor seconds NM bgrid; Described the first transistor NM adrain electrode be connected to the positive pole of described power vd D; The described second end N of described multi-channel LED array circuit is connected to the negative pole of described power vd D.
In one embodiment of the present of invention, each described LED array branch road comprises at least two LED, third transistor, the first operational amplifier opa, digital to analog converter DAC and resistance R, wherein: described at least two LED strip connection, and described at least two LED one end of series connection are connected to the first end A of described multi-channel LED array, and the other end is connected to the drain electrode of described third transistor; The source electrode of described third transistor is connected to one end of described resistance R and the inverting input of described first operational amplifier opa; The other end of described resistance R is connected to the output of described voltage follower; The input reception control signal of described digital to analog converter, output is connected to the in-phase input end of described first operational amplifier opa; The output of described first operational amplifier opa is connected to the grid of described third transistor.
In one embodiment of the present of invention, described voltage follower comprises the second operational amplifier opamp, the in-phase input end of described second operational amplifier opamp is connected to the described error input M of described drive circuit, the inverting input of described second operational amplifier opamp is connected to the output of described second operational amplifier opamp, and the output of described second operational amplifier opamp is connected to one end of the described resistance R of described LED array branch road.
In one embodiment of the present of invention, the described output of described second operational amplifier opamp is by reference to resistance Rs ground connection.
In the circuit provided in embodiments of the invention, between LED array branch road, add voltage follower.In this n channel LED array, even if each row LED luminance is different, namely each row flow through electric current I idifference, but during due to each channels operation, voltage follower, to the absorption compensation of difference currents, also can ensure the forward input D of LED array branch road ican regulate respectively and each passage M ithe voltage at place is consistent, thus achieves the independent regulation of each passage, adds the feasibility of circuit, substantially increases the efficiency of circuit.
 
Accompanying drawing explanation
Fig. 1 is the structural representation of the LED drive circuit of one embodiment of the invention.
Fig. 2 is the structural representation of the multi-channel LED array circuit of one embodiment of the invention.
Fig. 3 is the error signal of one embodiment of the invention and the schematic diagram compared of sawtooth signal.
 
Embodiment
The concrete structure of the LED drive circuit of embodiments of the invention is described in detail below in conjunction with accompanying drawing.
As shown in Figure 1, in one embodiment of the present of invention, a kind of multi-channel LED drive circuit comprises drive circuit 10 and multi-channel LED array circuit 11.
Drive circuit 10 is for providing drive current for the multi-channel LED array circuit 11 connected thereon.In embodiments of the invention, this drive circuit can be the circuit realizing DC-DC decompression transformation.Such as, in an embodiment, this drive circuit 10 can be BUCK drive circuit.
Such as, as shown in Figure 1, in an embodiment, this drive circuit 10 comprises power vd D, the first transistor NM a, transistor seconds NM b, inverter 101, inductance L, error amplifier 103 and comparator 105.
As shown in Figure 1, one end of inductance L is connected to the first end A of multi-channel LED array circuit 11, and the other end is connected to the first transistor NM asource electrode and transistor seconds NM bdrain electrode.
Transistor seconds NM bsource electrode be connected to the second end N of multi-channel LED array circuit 11.
The inverting input of error amplifier 103 is connected to the error input M of drive circuit 10; The in-phase input end of error amplifier 103 is connected to reference voltage VREF; The output of error amplifier 103 is connected to the inverting input of comparator 105.
The in-phase input end of comparator 105 is connected to saw-toothed wave generator (not shown in FIG.).
The output of comparator 105 is connected to the first transistor NM agrid and the input of inverter 101, and the output of inverter 101 is connected to transistor seconds NM bgrid.
The first transistor NM adrain electrode be connected to the positive pole of power vd D.
Second end N of multi-channel LED array circuit 11 is connected to the negative pole of power vd D.
In one embodiment of the present of invention, comparator 105 can be PWM comparator.
As depicted in figs. 1 and 2, in one embodiment of the present of invention, multi-channel LED array circuit 11 can comprise at least two LED array branch roads, and these at least two LED array branch circuit parallel connections are connected between the first end A of this multi-channel LED array circuit 11 and the second end N.Each LED array branch road comprises voltage follower, and each LED array branch road is connected to the error input M of drive circuit 10 by its voltage follower.
In one embodiment of the present of invention, multi-channel LED array circuit 11 is connected to drive circuit 10 and receives its drive current provided.This multi-channel LED array circuit 11 comprises multiple LED, and this drive current drives the plurality of LED, makes the plurality of LED luminous.
As shown in Figure 2, in one embodiment of the present of invention, multi-channel LED array 11 can comprise at least two LED array branch roads (in the embodiment of such as, Fig. 2, this multi-channel LED array 11 comprises n LED array branch road, wherein n be greater than or equal to 2 natural number).These at least two LED array branch circuit parallel connections are connected between the aforementioned first ends A of multi-channel LED array circuit 11 and the second end N.At least two the LED array branch roads being diverted to this parallel connection from the drive current of drive circuit 10 reception (are expressed as I Fig. 2 1-I n, as denoted by the arrows in fig. 2), with the LED in driving LED array branch.
As shown in Figure 2, in one embodiment of the present of invention, each LED array branch road can comprise at least two LED, (in Fig. 2, the third transistor of each LED array branch road is expressed as NM to third transistor 1-NM n, always be expressed as NM herein), the first operational amplifier of each LED array branch road is expressed as opa in first operational amplifier 111(Fig. 2 1-opa n, always be expressed as opa herein), (in Fig. 2, the digital to analog converter of each LED array branch road is expressed as DAC to digital to analog converter 1-DAC n, always be expressed as DAC herein) and resistance 112(Fig. 2 in always be expressed as R).
As shown in Figure 2, in one embodiment of the invention, these at least two LED strip connection, and these at least two LED one end of series connection are connected to the first end A of multi-channel LED array 11, and the other end is connected to the drain electrode of third transistor NM.
The source electrode of third transistor NM is connected to one end of resistance R and the inverting input of the first operational amplifier opamp.
The other end of resistance R is connected to the output of the voltage follower of the LED array branch road belonging to it.
(control signal that in Fig. 2, the digital to analog converter DAC of each LED array branch road receives is expressed as D to the input reception control signal of digital to analog converter DAC 1-D n), output is connected to the in-phase input end of the first operational amplifier opamp.
The output of the first operational amplifier opamp is connected to the grid of third transistor NM.
In the present embodiment, the first operational amplifier opamp constitutes follower.
As shown in Figure 2, in one embodiment of the present of invention, the second operational amplifier that the voltage follower of each LED array branch road comprises each LED array branch road in second operational amplifier 113(Fig. 2 always is expressed as opamp).The in-phase input end of this second operational amplifier opamp is connected to the error input M of aforesaid drive circuit 10, the inverting input of the second operational amplifier opamp is connected to the output of this second operational amplifier opamp, and the output of the second operational amplifier (opamp) is connected to one end of the resistance R of the LED array branch road belonging to it.
In one embodiment of the present of invention, as shown in Figure 2, in each LED array branch road, the output of the second operational amplifier opamp is also by reference to resistance Rs ground connection.
The operation principle of the circuit in previous embodiment of the present invention is as follows.
VDD provides DC power supply, and M node voltage delivers to the inverting input of error amplifier 103, with reference voltage V rEFafter relatively amplifying, obtain error signal V e.V ethe sawtooth waveforms produced as threshold voltage and the saw-toothed wave generator of comparator 105 compares (as shown in Figure 3), the switching signal control NM that comparator exports a, NM bbreak-make, realize the switch control rule of BUCK circuit.When switch controlling signal exports high level, NM aconducting, NM bturn off, provide input voltage by VDD, input voltage charges to inductance L, and the electric current on inductance increases, inductive energy storage.As switch controlling signal output low level NM bconducting, NM aduring shutoff, the electric current on inductance can not suddenly change, and inductance releases energy, and the electric current on inductance reduces gradually, for load provides electric current.Thus circuit is normally worked.
In voltage follower, the M of each LED array branch road ireference resistance R is accessed between point and ground s.Voltage follower maintains M in each passage ipoint voltage is consistent, according to Ohm's law, in each passage, flows through R selectric current I sidentical.
First operational amplifier opa of n channel LED array i-th passage (i.e. i-th LED array branch road) ifor follower, as input i-th port number character code D itime, then the i-th passage P iplace's voltage is also V i.The each passage of n channel LED array passes through M ipoint is linked together by voltage follower, then each passage M ipoint voltage is all identical, if M ipoint voltage is V.If regulate the i-th channel LED brightness namely to flow through electric current I respectively i, according to circuit KCL principle, flow into M ipoint electric current equal with the electric current of outflow, outflow through R selectric current constant, regulate the electric current I that each channel LED brightness causes idifference can by voltage follower maintenance each passage M icompensated by the output automatic absorption of voltage follower when point voltage is consistent.
In this way, in n channel LED array, even if each row LED luminance is different, namely each row flow through electric current I to profit idifference, but during due to each channels operation, voltage follower, to the absorption compensation of difference currents, therefore still can ensure opa iforward input D ican regulate respectively and each passage M ithe voltage at place is consistent, thus achieves the independent regulation of each passage, adds the feasibility of circuit, substantially increases the efficiency of circuit.
Described the present invention by specific embodiment above, but the present invention is not limited to these specific embodiments.It will be understood by those skilled in the art that and can also make various amendment, equivalent replacement, change etc. to the present invention, as long as these conversion do not deviate from spirit of the present invention, all should within protection scope of the present invention.In addition, " embodiment " described in above many places represents different embodiments, can certainly by its all or part of combination in one embodiment.

Claims (5)

1. a LED drive circuit, is characterized in that, comprising:
Drive circuit, described drive circuit is used for providing drive current;
Multi-channel LED array circuit, described multi-channel LED array circuit is connected to described drive circuit and receives described drive current, and described multi-channel LED array circuit comprises multiple LED, and described drive current drives described multiple LED to make described multiple LED luminous;
Described multi-channel LED array circuit comprises at least two LED array branch roads, and described at least two LED array branch circuit parallel connections are connected between the first end (A) of described multi-channel LED array circuit and the second end (N);
Wherein:
Each described LED array branch road comprises voltage follower, and described LED array branch road is connected to the error input (M) of described drive circuit by described voltage follower.
2. circuit as claimed in claim 1, it is characterized in that, described drive circuit comprises power supply (VDD), the first transistor (NM a), transistor seconds (NM b), inverter, inductance, error amplifier and comparator, wherein:
One end of described inductance is connected to the first end (A) of described multi-channel LED array circuit, and the other end is connected to described the first transistor (NM a) source electrode and described transistor seconds (NM b) drain electrode;
Described transistor seconds (NM b) source electrode be connected to described second end (N) of described multi-channel LED array circuit;
The inverting input of described error amplifier is connected to the described error input (M) of described drive circuit, and the in-phase input end of described error amplifier is connected to reference voltage (V rEF), the output of described error amplifier is connected to the inverting input of described comparator;
The in-phase input end of described comparator is connected to saw-toothed wave generator;
The output of described comparator is connected to described the first transistor (NM a) grid and the input of described inverter;
The output of described inverter is connected to described transistor seconds (NM b) grid;
Described the first transistor (NM a) drain electrode be connected to the positive pole of described power supply (VDD);
Described second end (N) of described multi-channel LED array circuit is connected to the negative pole of described power supply (VDD).
3. circuit as described in claim 1 or 2, it is characterized in that, each described LED array branch road comprises at least two LED, third transistor, the first operational amplifier (opa), digital to analog converter (DAC) and resistance (R), wherein:
Described at least two LED strip connection, and described at least two LED one end of series connection are connected to the first end (A) of described multi-channel LED array, and the other end is connected to the drain electrode of described third transistor;
The source electrode of described third transistor is connected to one end of described resistance (R) and the inverting input of described first operational amplifier (opa);
The other end of described resistance (R) is connected to the output of described voltage follower;
The input reception control signal of described digital to analog converter, output is connected to the in-phase input end of described first operational amplifier (opa);
The output of described first operational amplifier (opa) is connected to the grid of described third transistor.
4. as the circuit in claims 1 to 3 as described in any one, it is characterized in that: described voltage follower comprises the second operational amplifier (opamp), the in-phase input end of described second operational amplifier (opamp) is connected to the described error input (M) of described drive circuit, the inverting input of described second operational amplifier (opamp) is connected to the output of described second operational amplifier (opamp), and the output of described second operational amplifier (opamp) is connected to one end of the described resistance R of described LED array branch road.
5. circuit as claimed in claim 4, is characterized in that: the described output of described second operational amplifier (opamp) is by reference to resistance (Rs) ground connection.
CN201410475354.1A 2014-09-18 2014-09-18 A kind of LED drive circuit Active CN104254182B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410475354.1A CN104254182B (en) 2014-09-18 2014-09-18 A kind of LED drive circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410475354.1A CN104254182B (en) 2014-09-18 2014-09-18 A kind of LED drive circuit

Publications (2)

Publication Number Publication Date
CN104254182A true CN104254182A (en) 2014-12-31
CN104254182B CN104254182B (en) 2016-09-07

Family

ID=52188602

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410475354.1A Active CN104254182B (en) 2014-09-18 2014-09-18 A kind of LED drive circuit

Country Status (1)

Country Link
CN (1) CN104254182B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114639339A (en) * 2022-01-27 2022-06-17 南京中感微电子有限公司 LED display system and multi-path LED driving circuit thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101330787A (en) * 2007-06-21 2008-12-24 东部高科股份有限公司 LED drive circuit
CN101500358A (en) * 2008-01-28 2009-08-05 杭州士兰微电子股份有限公司 Output current compensation circuit of LED driving circuit
CN101754541A (en) * 2010-01-27 2010-06-23 英飞特电子（杭州）有限公司 DC bus voltage following control circuit suitable for multi-path parallel LEDs
CN101841949A (en) * 2009-03-20 2010-09-22 北京京东方光电科技有限公司 Backlight source driving circuit and driving method
JP2011114343A (en) * 2009-11-24 2011-06-09 Samsung Electronics Co Ltd Method of controlling supply source voltage, and multi-channel light-emitting diode driving circuit and multi-channel system using the same
CN102629458A (en) * 2011-10-21 2012-08-08 北京京东方光电科技有限公司 Backlight circuit, backlight panel and light emitting diode driver

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101330787A (en) * 2007-06-21 2008-12-24 东部高科股份有限公司 LED drive circuit
CN101500358A (en) * 2008-01-28 2009-08-05 杭州士兰微电子股份有限公司 Output current compensation circuit of LED driving circuit
CN101841949A (en) * 2009-03-20 2010-09-22 北京京东方光电科技有限公司 Backlight source driving circuit and driving method
JP2011114343A (en) * 2009-11-24 2011-06-09 Samsung Electronics Co Ltd Method of controlling supply source voltage, and multi-channel light-emitting diode driving circuit and multi-channel system using the same
CN101754541A (en) * 2010-01-27 2010-06-23 英飞特电子（杭州）有限公司 DC bus voltage following control circuit suitable for multi-path parallel LEDs
CN102629458A (en) * 2011-10-21 2012-08-08 北京京东方光电科技有限公司 Backlight circuit, backlight panel and light emitting diode driver

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114639339A (en) * 2022-01-27 2022-06-17 南京中感微电子有限公司 LED display system and multi-path LED driving circuit thereof
CN114639339B (en) * 2022-01-27 2023-09-26 南京中感微电子有限公司 LED display system and multi-path LED driving circuit thereof

Also Published As

Publication number Publication date
CN104254182B (en) 2016-09-07

Similar Documents

Publication Publication Date Title
US10381930B2 (en) Three-port direct current converter
CN101222805B (en) Method for multi-string LED time-sharing regulation and driving mechanism using the same
CN102014544B (en) LED (Light-Emitting Diode) lamp driving circuit
CN105657899B (en) Multipath LED constant current drive circuit and its control method
CN102118905B (en) Circuit suitable for multi-path LED current-sharing control
CN103596328B (en) A kind of LED drive circuit
CN103857152A (en) Power system with multiplexed output
CN101977469B (en) Adjustable LED drive power supply
CN102917499A (en) DC (Direct Current)/DC-based LED (Light Emitting Diode) driving controller for lighting
Attia et al. Design of decentralized street LED light dimming system
CN201854486U (en) Constant-current LED (light-emitting diode) driving power supply
CN201869400U (en) LED (light-emitting diode) lamp drive circuit
CN202565545U (en) Multipath light-adjustable constant-current output LED drive circuit
CN202514136U (en) Light emitting diode (LED) driving chip capable of dimming and driving circuit
CN203151813U (en) LED light source drive circuit
CN201750606U (en) Barrierless LED (light-emitting diode) driving circuit
CN104254182B (en) A kind of LED drive circuit
CN104270875B (en) LED (Light Emitting Diode)-driven control device and method
CN204031528U (en) A kind of energy-conservation driving circuit of high-power LED lamp
CN203289699U (en) LED (light-emitting diode) high-power drive circuit
CN100489949C (en) Driving device for light-emitting diode serial
CN104754838A (en) Multi-path LED drive circuit using solar energy to supply power
CN201682667U (en) Control circuit for automatically tracking driving voltage of LED
CN104010426B (en) A kind of suitable in the autonomous equalizing current circuit between the LED strip of multi-channel parallel
CN104023450B (en) A kind of multi-channel LED drive circuit

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant