CN105704858B - Driver for two or more parallel connection LED lamp strings - Google Patents
Driver for two or more parallel connection LED lamp strings Download PDFInfo
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- CN105704858B CN105704858B CN201610128020.6A CN201610128020A CN105704858B CN 105704858 B CN105704858 B CN 105704858B CN 201610128020 A CN201610128020 A CN 201610128020A CN 105704858 B CN105704858 B CN 105704858B
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- 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
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- 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
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- 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]
Abstract
A kind of LED driver for multiple LED strings, it has common node and multiple driver output nodes for connecting multiple LED strings.Main power circuit is provided, the main power circuit has the main output being connected with common node.Multiple slave power circuits are provided, there is the slave power circuit subordinate with corresponding one of driver output node connection to export respectively.
Description
The application is submission on November 5th, 2010, entitled " driver for being used for two or more parallel connection LED lamp strings ", Shen
Please number divisional application for being 201080071063.6.
Technical field
The present invention relates to LED driver circuit, and more particularly to the drive circuit for parallel connection LED lamp string and driving
The method of parallel connection LED lamp string.
Background technology
Due to the fast development on solid state illumination technology, light emitting diode (LEDs) in liquid crystal display, label and leads to
With obtaining extensive use in illumination.Compared with existing common light emitting source (such as incandescent lamp and fluorescent lamp), due in the absence of lamp
The High-Field sputtering of silk, LEDs have the relatively long working life of 80,000-100,000 hour.LEDs on the market
Now with less glass capsulation, this cause for operator their reliability and security be improved significantly.By
Can safely it be disposed in its life-span end in without poisonous mercury, LED.Other such as flicker frees, smooth light modulation, low pressure
Work and colour rendering well wait advantageous refinements to cause LED to turn into an emerging technology, and it in the near future can be in illumination city
Main status is occupied on.
Optical-electronic-heat (PET) theory of broad sense is pointed out, compared with single-chip high power designs, uses low-power chip
Device level multi-chip design has effect higher and the more low advantageous refinements of junction temperature.Similarly, on a system level, with system power
Identical is compared by the high-capacity LED s of the negligible amounts integrated systems formed, point based on the relatively low LED of multiple power
Cloth LED information display system has the advantages of similar.Due to the equipment and its luminous intensity and the forward current of application that LED is electric current driving
It is directly related, therefore when driving multiple LED, cascaded structure is better than parallel-connection structure, because all LED in Series lamp string can
To be worked under same current, and current sharing and chromaticity variation issue is not present.However, the LED quantity being connected in series is very
Limited in big degree by the output low pressure that power supply provides, thus the LED string of parallel connection especially suitable for high power applications (i.e.
>25W).Due to LED manufacturing tolerance, aging and temperature change, this parallel connection LED lamp string structure can trigger current unbalance problem,
So as to cause luminous intensity and color change.In addition, when using parallel connection LED lamp string in the case of no current composite device,
Even if the average current of each LED string is less than rated current, some or multiple LED strings may also exceed its maximum absolute amount
Determine electric current.
Several current sharing methods for being used to drive the multi-string LED being connected in parallel be present.A kind of directly mode be use with
The ballast resistor of each LED string series connection is so that difference between current is minimum.This mode is very simple；However, its operating efficiency is very
Difference, because very big power consumption can be produced on the ballast resistor used.It can be substituted using loss-free capacitor
The ballast resistor of loss, to reduce unnecessary loss when LED is driven with AC AC powers or is coupled with rectifier.This
The major defect of a little methods is the forward current that can not accurately control each LED string.At present, line is used in each lamp string
Property current regulator ensures good current sharing effect, but sizable power consumption is expended on current regulator.It is another
Kind mode is to set up single voltage source for each LED string.A kind of turn based on input connection in parallel or series can be used
The modular power converter structure of parallel operation, wherein the converter has independent LED string load.Independent detection and control
The electric current of each LED string is to follow same datum.Due in the absence of lossy ballast resistor or linear current regulators, this
Two kinds of LED driver structures have relatively higher conversion efficiency.However, it is this constructively complex as well as expensive, because each LED
String is required for a set of main circuit and controller.
The content of the invention
The invention provides a kind of LED driver for being used to drive multiple parallel connection LED lamp strings, it has public main power
The slave power converter of converter and parallel cascade.Main power converter is used to provide for the overwhelming majority of driving voltage, tool
The multiple slave converters modules for having voltage-regulation provide remaining balanced voltage to control each LED string electric current respectively.It is main
Power converter can be controlled by PWM to be dimmed to LED string.Main power converter should provide the exhausted of total output voltage
It is most of, while slave power converter provides remaining a small amount of part of this voltage.Preferably but not necessarily, main power conversion
Device provides percent 90 (90%) of the nominal supply voltage of LED string.Residue percent on the voltage of each LED string
Ten (10%) are provided by one of slave power converter.Slave power converter adjusts residual voltage to balance each parallel connection LED lamp
Electric current on string.Slave converters can carry out switch control using semiconductor switch (such as power MOSFET) or magnetic amplifier
System.
Present invention also offers by provided from single main power converter circuit lamp string supply voltage Part I and
Two or more parallel connections are driven from the second remainder of the voltage of the independent each LED string of slave power converter offer
The method of LED string.Independent slave power converter is used for each LED string, and this method is including separately adjustable remaining
Voltage segment is to balance the electric current in each LED string.
Therefore, disclosed herein is a kind of LED driver, the driver includes common node, multiple driver output nodes,
Wherein in use, multiple LED strings are connected between corresponding driver output node and common node, have with it is public
The main power circuit of the main output of node connection, and multiple slave power circuits, each slave power circuit have with it is corresponding
One of driver output node connection subordinate output.
Also disclosed herein a kind of LED driver, the driver includes common node, at least two output nodes, generation
The main power circuit for the principal voltage output being connected with common node, at least two slave power circuits, each slave power circuit
Adjusted voltage output is generated, adjusted voltage output is connected with corresponding one of output node, wherein public section
Driving voltage between point and one of driver output node include principal voltage and corresponding one of dependent voltage it
With.
Each subordinate output can be connected in series with main output.Main power circuit and slave power circuit are preferably configured to lead
Voltage is more than any dependent voltage, and is larger about more preferably 9 times than any dependent voltage, but those skilled in the art will recognize
Know, in preferred aspect, secondary circuit is separately adjustable, therefore voltage ratio can change in use.
Main power circuit and/or slave power circuit are preferably switched-mode power supply.It is highly preferred that power circuit includes tool
There is the forward converter of transformer, the transformer has the first and second secondary windings, wherein main power circuit connection first
Secondary windings, each slave power circuit connect second subprime winding.Each slave power circuit can have semiconductor switch (such as
Power MOSFET) or magnetic amplifier, and feedback circuit is with separately adjustable each slave power circuit.Primary circuit connects transformer
Armature winding, and including PWM controlling switches to adjust the power of armature winding.
The other side of the present invention will become apparent from following description, and the description simply provides by way of example
With the specific embodiment of the explanation present invention.
Brief description of the drawings
The accompanying drawing description present invention is will refer to now, wherein：
Fig. 1 a, 1b and 1c are the schematic diagrames for reducing by three of current unbalance in parallel connection LED lamp string kinds of art methods；
Fig. 2 a are the schematic diagrames according to the LED driver of the present invention；
Fig. 2 b are the diagrams of the voltage output of LED driver；
Fig. 3 is the circuit diagram of LED driver；
Fig. 4 shows the Lf-Vm curves of LED driver；
Fig. 5 be there is PWM to dim, according to the present invention LED driver second embodiment circuit diagram；
Fig. 6 be there is PSPWM to dim, according to the present invention LED driver 3rd embodiment circuit diagram；
Fig. 7 shows the LED string of the LED string and (b) mismatch for (a) matching, to be driven according to the LED of the present invention
The waveform of primary switch electric current Ip and secondary rectifier voltage Vr, Vr1, Vr2 and Vr3 exemplified by device；
Fig. 8 is shown under (a) 100%, (b) 80%, (c) 50% and (d) 20% traditional PWM Dimming operations, is measured
The obtained LED string current waveform on the LED driver example according to the present invention；
Fig. 9 shown under (a) 80%, (b) 50% and (c) 20% PSPWM Dimming operations, measure to obtain on root
According to the LED string current waveform of the LED driver example of the present invention；
Figure 10 shows the drive adjusted according to the LED driver example of the present invention and the multi output magnetic amplifier of prior art
Efficiency comparison between dynamic device；And
Figure 11 is to be used to drive with the LED according to the present invention that red, green and blue (RGB) LED string are used together
The circuit diagram of the 3rd embodiment of device.
Embodiment
Before the embodiments of the invention are explained in detail, it should be recognized that application of the invention is not limited to propose in description below
Or the CONSTRUCTED SPECIFICATION shown in accompanying drawing.The present invention can have other embodiments, and can be practiced or carried out in a variety of ways.
It will also be appreciated that term used herein and term are descriptive, it is not construed as restricted.
The invention provides a kind of driver for parallel connection LED lamp string, and it has " public " for all LED strings
Primary, voltage source (Vm) and for each LED string (S1, S2..Sn) to carry out the separate subordinate voltage source (Vs1- of current regulation
Vsn), as shown in Figure 2 a.Referring to Fig. 2 a and Fig. 2 b, the most of of power consumed in each lamp string is presented by " master " voltage source (Vm)
Send, and the electric current that corresponding dependent voltage source (Vs1, Vs2 ... Vsn) is used to adjust in each LED string (S1, S2 ... Sn) is so as to electricity
Mobile equilibrium.To avoid bigger power consumption, all main DC sources and subordinate DC source should be the converter of switching mode.This is for tool
It is very important to have for the LED of wide device parameter tolerance.For example, under 45mA, the forward voltage meeting of 8 LED strings
Change between 21.9V-31.7V.If using linear current regulators, the linear current of the minimum lamp string of forward voltage is adjusted
The pressure drop of section device both sides will be up to 9.8V, and in the case where forward current is larger, the power consumption on current regulator is unacceptable
's.For example, typical 0.3A lamp string electric current will cause about 3W power consumption in each lamp string.Driven according to the LED proposed
Device structure, it can be established as pressing between the main sources of the public 20V of all 8 lamp strings and covering parallel connection LED lamp string in each lamp string
The independent low pressure dependent voltage source of difference.Therefore, most of power is provided by main source, and only dump power is carried by corresponding subordinate source
For.
There can be multiple layouts independently exported using various in the present invention.However, for business application, drive
Dynamic device should preferably meet following technical requirements：
1) it is electrically isolated：Need to be electrically isolated between main source and subordinate source, because their terminal can not share identical and connect
Ground.However, it need not be electrically isolated between subordinate source.
2) adjusted output：The voltage at LED string both ends should be adjusted to adapt to different forward current and environment temperature
Degree.It is therefore preferable that multiple outputs through independence and accurate adjustment；
3) modularization：It is this to be laid out what is preferably easily extended, therefore preferred module formula mode.
4) power distribution：Most LED power should be provided by main source, and dump power is provided by subordinate source.The circuit
Embodiment should realize this power distribution.
Based on these considerations, the first embodiment of LED driver layout is shown in Fig. 3, it has magnetic amplifier (mag-
Amp) rear class adjuster.Magnetic amplifier rear class regulator layout has high efficiency high, stability, power density height, control simple
The features such as low with electromagnetic interference.It should be noted, however, that based on power semiconductor switch (such as MOSFET rather than magnetic amplifier)
Standard switch-mode power governor can be used for the subordinate rear class adjuster in Fig. 3.Only need two secondary of transformer
Winding Ns1 and Ns2 exports to generate multiple (two or more).One secondary windings Ns1 output is used for main source Vm, and it is by first
The PWM controls of power converter on level side.Another secondary windings Ns2 output is used by detecting LED forward current bases
Multiple subordinate source Vs1, Vs2 ..., Vsn (Fig. 3 are generated in independent transductor regulator Lm1, Lm2 with backfeed loop v1, v2
In two subordinate sources are only shown, source but more can be used for more LED strings).It is worth noting that, the present invention
Two advantages of structure are：First, it is only necessary to which two secondary windings generate multiple outputs, so as to forming more simple transformation
Device structure, lower production cost and less leakage inductance；Secondly, each transductor regulator Lm1, Lm2 are only used for handling
Fraction power on each LED string, therefore the size of magnetic amplifier core is much smaller and its power consumption is relatively low.
Transductor regulator provides power regulation functions for the Partial Power on each LED string.If lamp string electric current Io1
More than reference current Iref, then the magnetic amplifier inductance Lm1 blocking duration will be increased by adjusting the output of reset circuit
Add so that Vs1 declines and Io1 accordingly reduces to meet Iref.As shown in Figure 3, it can be seen that the work(provided for each LED string
Rate is made up of two parts, i.e., main source and independent subordinate source.If the forward voltage drop of LED string is constant, in main source and subordinate
Countless distributed combination between source be present.Therefore, how qualitative analysis is found to optimal distribution herein.
A. power distribution
First, under all working state, the voltage in main source have to be lower than all forward voltage drops of LED string, because main
Source should provide the overwhelming majority (but not all) of the power of all LED strings, i.e. Vm<Vled_min.Subordinate source be able to should adjust
LED string both end voltage part is saved to adjust their forward current.
Secondly, main source is lower, and subordinate source is then higher, because their summation should be equal to the voltage at whole LED string both ends.
In extreme circumstances, if main source voltage is zero, the circuit reduction proposed into routine the converter with multiple outputs,
In this case, each LED string is powered by single source completely.Two shortcomings in the extreme case be present.In each source
The voltage stress of commutation diode will significantly increase, it is therefore necessary to use the of a relatively high high-voltage diode of pressure drop.Second
Shortcoming is to need bigger output filter inductance to meet output current ripple requirement in each source.In addition, magnetic is put
Power consumption on big device will increase, because it must block the sufficiently high voltage for whole LED string.In the present invention,
Common power source provides mains voltage for all LED strings.Therefore, can be that subordinate source selects such as Schottky diodes
Power diode with low rated voltage and low forward voltage drop, and smaller output filter inductance.
In this analysis, it is assumed that all LED strings share same current and have identical forward voltage drop VF, and all lamps
The summation of string electric current is IF.All output filter inductive currents are assumed with identical ripple current factor gamma.For each
For LED string is provided the occasion of power by single source completely, the output filter inductance needed in each output is：
Wherein D be secondary windings in voltage pulse duty cycle, Ts be secondary windings in voltage pulse switch periods, n
For the quantity of LED string.For convenience, in formula (1)Value be defined as α.
Then for the driver proposed, the output filter inductance required by main source is
Output filter inductance required by each subordinate source is：
Then curves of the Lf to Vm can be obtained, as shown in Figure 4.If loading has three LED strings, i.e. n=3, if
Determine Vm=0.9VF (i.e. shared power source provides the 90% of output voltage), then a pass is needed in the driver proposed
In the inductance that Vm is 0.3 α, and three on inductance that Vs1-Vs3 is respectively 0.1 α.
Core on magnetic amplifier core, which damages, is：
Pcore=(9.93 × 10-6)·(f1.57)·(B1.70) (4)
Equation (4) shows that core damage is directly proportional to magnetic flux density.In our proposal, the subordinate source of magnetic amplifier core is used
Voltage be far below LED string both ends whole voltage.Therefore, equation (4) is theoretically confirmed in this suggestion, magnetic amplifier
Power consumption decrease.
B. light-dimming method
Traditionally there are two kinds of light regulating technologies for being used to drive LED：Amplitude mode and PWM mode.However, PWM dims method
Preferably received in performance application (such as showing panel), because LED levels of current and thus colour temperature can be with
It is kept, and amplitude mode is then received by common public illumination application.
In the present invention, light modulation can be realized by traditional PWM scheme and phase-shifting PWM (PSPWM) scheme.Fig. 5 is (only
Two LED strings are shown) in show the circuit diagram of the LED driver system with traditional PWM dimming functions proposed, its
Middle Rs1 and Rs2 are respectively LED string S1 and S2 current sense resistor, and Q is PWM dimmer switch, and the circuit in dotted line square frame is
The reset circuit of magnetic amplifier.Method is dimmed different from the traditional PWM being used together with linear current regulators, in the suggestion,
All LED strings only need a MOSFET (dimmer switch), and it does not work in linear impedance area, but in saturation region work
Make.Therefore, the conductance power consumption in the dimming process can be reduced.However, it is necessary to difference amplifier (DA1) detects LED current
Signal, because all current sense resistors do not share common ground (due to only using a dimmer switch Q).By the electricity of detection
Stream signal is made comparisons with Iref to adjust the reset current of magnetic amplifier.Zener diode Zd1 specific use acts as voltage
Converter, because multiple output voltages of converter will not be identical with the voltage level of error amplifier.In Q closed-down periods
Between, the high-frequency switching operation of primary main switch can be stopped further to reduce switching loss.If dimmer switch Q is short
Road, then it can realize that amplitude mode dims by adjusting current reference value Iref.
The defects of to avoid traditional PWM from dimming, (such as trembles larger input/output electric current and the EMI performances degenerated),
PSPWM dimming functions can be used.The LED driver system with PSPWM dimming functions proposed is shown in Fig. 6, its
In each LED string use a dimmer switch.In Fig. 6 reset circuit, PNP transistor (Qr1) is added to error letter
In the output of number amplifier.Its effect will be explained below.By taking LED string S1 as an example.In the Q down periods, if without using
Qr1, the then electric current detected are that 0 and EA1 output voltage is higher.This situation will cause reset current for saturable electricity
Too small for anti-device Lm1, Lm1 will lose its magnetic amplifier function, and Vs1 will raise to far above its desired value.That is, Vs1 loses
Control.When adding Qr1, EA1 output voltage is approximately 0, then Lm1 reset current will increase to prevent to come from secondary windings
Ns2 voltage pulse.Therefore, saturable reactor must be engineered to bear whole Flux consumptions of input waveform.
In the case that all PWM dim signals are simultaneously relatively low, the main switch in the primary side of transformer will be turned off to reduce switch damage
Consumption.All PWM dim signals are carried out by Dr1-Drn or computing is to detect the signal.
The performance of the LED driver proposed is verified by the prototype with the single-ended forward converters of 120kHz, described
There is converter the 3rd transformer to be worked by 20-30V voltage source to reset winding.Utilize three CREE cool whites LED in parallel
(model XREWHT-L1-WG-Q5-0-04) lamp string assesses the performance of proposed LED driver, wherein in each lamp string
It is in series with 6 LED.Under 350mA, each LED typical forward voltage is 3.3V, and desired Vm is set as 17V.Circuit
Critical component is listed in table 1.Inductance value is determined by (1)-(3).
Table 1
| Primary main switch | IRF540N |
| The turn ratio of transformer | Np:Nr:Ns1:Ns2=12:12:24:5 |
| The rectifier in main source | BYW51-200 |
| The rectifier in subordinate source | 42CTQ030S |
| The filter inductance in main source | 530μH |
| The filter inductance in subordinate source | 170μH |
| PWM controller | SG3525A(120kHz) |
| Lm1~Lm2 | AMG-12S,16T |
| Zd1~Zd3 | 1N5349B |
| Qd1~Qd3 | TIP127 |
| EA1~EA3 | LM358 |
Fig. 7 shows the main waveform of LED driver.Fig. 7 (a) shows primary switch electric current Ip and secondary rectifier electricity
Press Vr, Vr1, Vr2 and Vr3 waveform.It can be seen that pulse width is inconsistent.Vr3 pulse width is slightly shorter than Vr1's and Vr2.
The voltage of measurement is Vm=17.06V, Vs1=1.87V, Vs2=1.88V, Vs3=1.72V.In order to confirm that proposed LED drives
Dynamic device can adjust driving voltage to reduce current unbalance, add 2.2 Ω's and 3.9 Ω to the 2nd and the 3rd LED string respectively
Resistance, to establish the mismatch Conditions exaggerated among 3 LED strings.Fig. 7 (b) shows the new waveform under this state.Such as
Desired such, Vr3 pulse width is most wide, because the 3rd lamp string has highest additional resistance；Vr2 pulse width
Wider than Vr1, wherein Vr1 holding is constant.The voltage newly measured is Vm=17.06V, Vs1=1.87V, Vs2=2.52V,
Vs3=2.94V.
Fig. 8 shows the LED string electric current measured under different duty cycles using traditional PWM light modulations method (referring to Fig. 5).When only
, can be under different duty cycles on three LED strings by the voltage for adjusting three subordinate sources during with a dimmer switch
Obtain identical amplitude 300mA.Fig. 9 shows the LED proposed under different duty cycles using PSPWM light modulations method (referring to Fig. 6)
The waveform of driver.Equally, good current balance type is actually obtained under all of these conditions.
To be compared, C.-C.Chen, C.-Y.Wu and T.-F.Wu are established in Proc.IEEE PESC, 2006,2949-
" the Fast transition current-type burst-mode dimming control for the LED of page 2955
Described in back-light driving system of LCD TV " (entire contents are incorporated by reference herein)
The driver of traditional LED magnetic amplifiers regulation.Figure 10 shows that under different input voltages the LED proposed measured drives
The gross efficiency of device and legacy drive.Due to the relatively low work(using public power source and magnetic amplifier rear class adjuster
Rate processing requirement, therefore the scheme proposed can realize higher energy efficiency.
For LCD backlight application, usually using RGB LEDs so that the light of three kinds of colors is blended together into white light.It is however, red, green
Color is different with the nominal forward voltage of blue led.The forward voltage of the red LED of same manufacturer is less than green and blue led
, the forward voltage of green LED is roughly the same with blue led.In view of these factors, the LED driver proposed is suitable to
RGB LED are applied.The circuit proposed can be used for this application.In fig. 11, red LED lamp string provides work(by main source
Rate, green and blue led lamp string combine offer power by main source and corresponding subordinate source.The electric current of green and blue led
Current sharing is individually adjusted to by corresponding suitable dependent voltage source respectively；However, the electric current of red LED lamp string only by
Primary, voltage source is adjusted so as to current sharing.
Claims (13)
1. a kind of LED driver for being used to drive multiple parallel connection LED lamp strings, the LED driver include：
Public main power converter；And
The slave power converter of multiple parallel cascades, each slave power converter is both electrically connected with to be turned in the public main power
Between parallel operation LED string corresponding with the multiple parallel connection LED lamp string；
Wherein, in use, the public main power converter is configured to supply in the multiple parallel connection LED lamp string
The principal voltage of the driving voltage of each, and each of multiple slave power converters are configured as to corresponding
LED string provides the dependent voltage of the driving voltage, wherein the driving voltage includes the principal voltage and subordinate electricity
The sum of pressure, wherein the principal voltage is more than the dependent voltage；And
Wherein the multiple slave power converter is configured as adjusting the dependent voltage to balance the multiple parallel connection LED lamp
Electric current in string.
2. LED driver as claimed in claim 1, wherein the public main power converter be configured as to it is the multiple simultaneously
Join the voltage that each of LED string provides 90%, and each of the multiple slave power converter is configured
To provide 10% voltage to corresponding LED string.
3. LED driver as claimed in claim 1, further comprise the power converter with transformer, the transformation utensil
There are armature winding, the first secondary windings and second subprime winding；Wherein described public main power converter and first level
Winding is connected and each of the multiple slave power converter is connected with the second subprime winding.
4. LED driver as claimed in claim 3, further comprise being connected with the armature winding of the transformer just
Level circuit, the primary circuit include pulse width modulation controlling switch for adjusting to the power of the armature winding.
5. LED driver as claimed in claim 3, wherein the power converter is to reverse converter or forward converter.
6. LED driver as claimed in claim 1, wherein the LED driver further comprise being used for controlling it is the multiple
The feedback circuit of the saturation of at least one of slave power converter.
7. LED driver as claimed in claim 6, wherein the feedback circuit is by detecting the forward direction in the LED string
Electric current controls the saturation of at least one of the multiple slave power converter.
8. LED driver as claimed in claim 1, wherein the public main power converter is controlled by pulse width modulation
To be dimmed to the multiple LED string.
9. LED driver as claimed in claim 1, wherein the multiple slave power converter is by pulse width modulation control
Make to be dimmed to the multiple LED string.
10. the LED driver as described in any one of claim 1-9 claim, wherein the multiple slave power is changed
Each of device includes being used for the magnetic amplifier or power semiconductor switch for adjusting or switching control.
11. the LED driver as described in any one of claim 1-9 claim, wherein the public main power converter
Including switched-mode power supply.
12. the LED driver as described in any one of claim 1-9 claim, wherein the multiple slave power is changed
Device includes switched-mode power supply.
13. a kind of LED driver for being used to drive multiple parallel connection LED lamp strings, the LED driver include：
Public main power converter；And
The slave power converter of multiple parallel cascades, each slave power converter is both electrically connected with to be turned in the public main power
Between parallel operation LED string corresponding with the multiple parallel connection LED lamp string；
Wherein, in use, the public main power converter is configured to supply in the multiple parallel connection LED lamp string
Whole voltages of one, and the principal voltage of the driving voltage for each of remaining multiple parallel connection LED lamp strings is provided, and
And each of multiple slave power converters be configured as to corresponding LED string provide the driving voltage from
Belong to voltage, wherein the driving voltage includes the principal voltage and the sum of the dependent voltage, wherein the principal voltage is more than institute
State dependent voltage；And
Wherein the multiple slave power converter is configured as adjusting the dependent voltage to balance the multiple parallel connection LED lamp
Electric current in string.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610128020.6A CN105704858B (en) | 2010-11-05 | 2010-11-05 | Driver for two or more parallel connection LED lamp strings |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610128020.6A CN105704858B (en) | 2010-11-05 | 2010-11-05 | Driver for two or more parallel connection LED lamp strings |
| CN201080071063.6A CN103493594A (en) | 2010-11-05 | 2010-11-05 | Driver for two or more parallel LED light strings |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201080071063.6A Division CN103493594A (en) | 2010-11-05 | 2010-11-05 | Driver for two or more parallel LED light strings |
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| Publication Number | Publication Date |
|---|---|
| CN105704858A CN105704858A (en) | 2016-06-22 |
| CN105704858B true CN105704858B (en) | 2018-03-23 |
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| US20230324036A1 (en) * | 2022-04-07 | 2023-10-12 | Globe Electric Company Inc. | Duo led light fixture with a downlight source and an optionally operable upper light source |
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| CN107071980A (en) * | 2017-05-08 | 2017-08-18 | 生迪智慧科技有限公司 | Multichannel LED drive circuit |
| CN108055728B (en) * | 2017-12-27 | 2024-04-09 | 生迪智慧科技有限公司 | Multi-path light-emitting diode (LED) driving circuit and driving method |
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| CN1600047A (en) * | 2001-12-05 | 2005-03-23 | 皇家飞利浦电子股份有限公司 | LED driver circuit with PWM output |
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| US7148632B2 (en) * | 2003-01-15 | 2006-12-12 | Luminator Holding, L.P. | LED lighting system |
| WO2009044340A2 (en) * | 2007-10-02 | 2009-04-09 | Nxp B.V. | Method and circuit arrangement for determining the light output level of a led |
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| CN1600047A (en) * | 2001-12-05 | 2005-03-23 | 皇家飞利浦电子股份有限公司 | LED driver circuit with PWM output |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US20230324036A1 (en) * | 2022-04-07 | 2023-10-12 | Globe Electric Company Inc. | Duo led light fixture with a downlight source and an optionally operable upper light source |
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