CN102256421A - High-precision multipath LED (light-emitting diode) current-equalizing circuit - Google Patents
High-precision multipath LED (light-emitting diode) current-equalizing circuit Download PDFInfo
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- CN102256421A CN102256421A CN2011102184932A CN201110218493A CN102256421A CN 102256421 A CN102256421 A CN 102256421A CN 2011102184932 A CN2011102184932 A CN 2011102184932A CN 201110218493 A CN201110218493 A CN 201110218493A CN 102256421 A CN102256421 A CN 102256421A
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Abstract
The invention relates to a high-precision multipath LED (light-emitting diode) current-equalizing circuit, which comprises multipath LED lighting branch circuits in parallel connection with one another, wherein in each path of LED lighting branch circuit, the anode of an LED is connected to an anode output end of an externally connected power supply; the cathode of the LED of any path of the LED lighting branch circuits is connected to a first resistor, a second resistor and a cathode output end of the externally connected power supply in turn; the cathodes of the LEDs of other branch circuits in the multipath LED lighting branch circuits are all connected to collector electrodes of triodes; emitting electrodes of the triodes are all connected to sampling resistors and the cathode output end of the externally connected power supply in turn; the resistance values of the sampling resistors are as same as the resistance value of the second resistor; base electrodes of the triodes are respectively connected to output ends of operational amplifiers; the non-inverting input ends of the operational amplifiers are all connected to a second end of the first resistor; and inverting input ends of the operational amplifiers are all connected to the corresponding emitting electrodes of the triodes. The high-precision multipath LED current-equalizing circuit can be used for realizing the high-precision current equalization of multipath LEDs. The circuit is simple in structure.
Description
Technical field
The present invention relates to a kind of high accuracy LED multi-path flow equalizing circuit.
Background technology
As everyone knows, LED needs constant-current driving, and for high-power LED, because the inconsistency of its forward voltage drop causes it directly in parallelly not use.But in some application scenario, because a maximum number of the LED that the restriction of safety extra low voltage makes series connection is restricted.
The flow equalizing circuit of existing parallel connection LED is realized by mirror current source usually, its circuit theory as shown in Figure 1, by the flow equalizing circuit that this form realizes, its current-sharing precision is subjected to the Vbe influence of triode, and the electric current of two-way is also variant when the Vbe of different triodes is variant.Owing to the negative temperature characteristic of triode Vbe, Vbe will produce bigger deviation along with the difference of temperature when two triode temperature are inconsistent, influence the current-sharing precision equally simultaneously.The effect of R2～R (n+1) is to reduce because the difference of the two-way electric current that Vbe pressure reduction causes; usually can to get the pressure reduction at R2～R (n+1) two ends consistent with Vbe or approaching in order to reach good effect; but, will cause the loss on R2～R (n+1) to increase like this, reduce the whole efficiency of system.In addition, because the deviation of LED forward voltage drop VF, when deviation is excessive, can make the system can't operate as normal.Illustrate, as shown in Figure 1, when the VF sum of all LED on this road of I2 series connection is above less than the VF sum 0.7V of all LED series connection on this road of I1, triode Q2 this moment saturation conduction, the pressure reduction that can't reduce Vce again makes system balancing, this will cause system's cisco unity malfunction, just can't realize the effect of two-way current-sharing.
Summary of the invention
Technical problem to be solved by this invention is to provide the high accuracy LED multi-path flow equalizing circuit that a kind of circuit structure is simple, can realize high-precision current-sharing effect at above-mentioned prior art.
The present invention solves the problems of the technologies described above the technical scheme that is adopted: this high accuracy LED multi-path flow equalizing circuit, the luminous branch road of LED multi-path that comprises connection parallel with one another, LED is anodal in the luminous branch road of each paths of LEDs all is connected with the external power supply cathode output end, it is characterized in that: the LED negative pole of any branch road connects first end of first resistance in the luminous branch road of described LED multi-path, second end of first resistance connects first end of second resistance, and second end of second resistance is connected with the external power supply cathode output end; The LED negative pole of other branch roads all connects the collector electrode of a triode in the luminous branch road of described LED multi-path, the emitter of this triode is connected with the external power supply cathode output end after all connecting a sampling resistor, and the resistance of all sampling resistors is all identical with described second resistance; In addition, the base stage of all triodes links to each other with the output of an operational amplifier respectively, the in-phase input end of all operational amplifiers all links to each other with second end of described first resistance, and the emitter of the triode on the inverting input of all operational amplifiers and the luminous branch road of corresponding LED links to each other.
As improvement, between the base stage of all triodes and ground, be connected an electric capacity respectively.
Compared with prior art, the invention has the advantages that: can realize the sampling of low-voltage, reduce the loss on sampling resistor.Simultaneously, use amplifier can realize high-precision current-sharing effect, and do not have temperature to float.In addition by regulating the resistance of R1, can well adapt to LED pressure drop between each road and difference, the present invention is a kind of current-sharing scheme of high-efficiency high-accuracy.
Description of drawings
Fig. 1 is the circuit theory diagrams of LED flow equalizing circuit in the prior art.
Fig. 2 is the circuit theory diagrams of the embodiment of the invention one.
Fig. 3 is the circuit theory diagrams of the embodiment of the invention two.
Fig. 4 is the circuit theory diagrams of the embodiment of the invention three.
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
Embodiment one
Referring to LED flow equalizing circuit shown in Figure 2, the luminous branch road of two paths of LED that comprises connection parallel with one another, in the luminous branch road of this two paths of LED, be composed in series LED electroluminescent lamp string by plurality of LEDs, wherein the anodal of LED electroluminescent lamp string all is connected with the external power supply cathode output end, wherein the negative pole of LED electroluminescent lamp string connects first end of first resistance R 1 in the luminous branch road of first paths of LEDs, second end of first resistance R 1 connects first end of second resistance R 2, and second end of second resistance R 2 is connected with the external power supply cathode output end; The negative pole of LED electroluminescent lamp string connects the collector electrode of a triode Q1 in the luminous branch road of second paths of LEDs, and the emitter of this triode Q1 connects one and adopts resistance R 3 backs to be connected with the external power supply cathode output end, and the resistance of sampling resistor R3 is identical with described second resistance R 2; In addition, the base stage of triode Q1 links to each other with the output of an operational amplifier N1, and the in-phase input end of operational amplifier N1 links to each other with second end of described first resistance R 1, and the inverting input of operational amplifier N1 links to each other with the emitter of triode Q1.Between the base stage of described triode and ground, be connected a capacitor C 1.
When flowing through second resistance R 2, the circuit I 1 in the luminous branch road of first paths of LEDs produces a la tension de reference Uref est; Realize closed-loop control by operational amplifier in the luminous branch road of second paths of LEDs, this closed-loop control is electric current series connection negative feedback, and triode Q1 emitter links to each other with the inverting input of operational amplifier, no matter is in DC channel, still in alternating current path, feedback all exists.As Uref during greater than Uf1, the voltage U 1 at transistor base place is for just, and circuit I 2 electric currents in the luminous branch road of second paths of LEDs increase, and Uf1 increases, and causes Δ U=(Uref-Uf1) to reduce, and forms the negative feedback of circuit.Vice versa.Final in system stability, Uref=Uf1, at this moment, because R2=R3 can realize I1=I2.
The current error of following this circuit two-way of surface analysis, the steady-state error of general dc current stabilized power supply can be divided into two classes: the first kind is static receiver error (an abbreviation static difference), relevant with the type and the input signal of power-supply system, comprise given static difference and disturbance static difference, static difference can overcome by the adjusting of system; Second class is a systematic error, mainly by the temperature of current sampling unit, adjuster, device float, in time, floats and causes, is the error that power-supply system can't overcome.The negative-feedback circuit that present embodiment adopts operational amplifier to realize can effectively be eliminated static difference.And its systematic error mainly contains that the adjusting deviation of the resistance of sampling resistor and amplifier causes, resistance can select for use the F shelves to get Chip-R, and the adjusting deviation of amplifier can be ignored itself, finally realizes the precise current-equalizing of two-way.Between transistor base and ground, increase the variation that capacitor C 1 can be slowed down the voltage U 1 at transistor base place, increase the stability of system.
Embodiment two
Different with embodiment one is, comprise the luminous branch road of three paths of LEDs, referring to shown in Figure 3, wherein in the luminous branch road of Third Road LED, also be composed in series LED electroluminescent lamp string by plurality of LEDs, the anodal of Third Road LED electroluminescent lamp string is connected with the external power supply cathode output end equally, the negative pole of Third Road LED electroluminescent lamp string connects the collector electrode of triode Q2 equally, triode Q2 emitter is connected with the external power supply cathode output end after connecting sampling resistor R4, the base stage of triode Q2 also connects the output of an operational amplifier N2, the in-phase input end of operational amplifier N2 links to each other with second end of first resistance R 1, the inverting input of operational amplifier N2 links to each other with the emitter of triode Q2, also is connected with a capacitor C 2 between the base stage of triode Q2 and the ground.
Produce a la tension de reference Uref est when equally, the circuit I 1 in the luminous branch road of first paths of LEDs flows through second resistance R 2; The luminous branch road of two paths of LED is all realized closed-loop control by amplifier in addition, and this closed-loop control is electric current series connection negative feedback.The emitter of triode Q1 links to each other with the inverting input of operational amplifier N1, no matter is in DC channel, and still in alternating current path, feedback all exists.As Uref during greater than Uf1, U1 is for just, and the I2 electric current increases, and Uf1 increases, and causes Δ U=(Uref-Uf1) to reduce, and forms the negative feedback of circuit.Vice versa.Final in system stability, Uref=Uf is because R2=R3 can realize I1=I2.In like manner, triode Q2 emitter links to each other with the inverting input of operational amplifier N2, and as Uref during greater than Uf2, U2 is for just, and the I3 electric current increases, and Uf2 increases, and causes Δ U=(Uref-Uf2) to reduce, and forms the negative feedback of circuit.Vice versa.Final in system stability, Uref=Uf2 is because R2=R4 can realize I1=I3.Finally, i.e. I1=I2=I3.Realize 3 tunnel current-sharings.
Embodiment three
Narration through embodiment one and two, we can extend to thought of the present invention LED multi-path flow equalizing circuit more than three tunnel, referring to shown in Figure 4, as long as the LED negative pole of other branch roads is all connected the collector electrode of a triode Q2, Q3, Q (n-1), the emitter of all triode Q2, Q3, Q (n-1) connects one respectively and adopts resistance R 3, R4, R (n+1) back to be connected with the external power supply cathode output end, and the resistance of all sampling resistor R3, R4, R (n+1) is all identical with described second resistance R 2; And, the base stage of all triode Q2, Q3, Q (n-1) is linked to each other with the output of an operational amplifier N2, N3, N (n-1) respectively, the in-phase input end of all operational amplifier N2, N3, N (n-1) all links to each other with second end of described first resistance R 1, triode Q2, Q3 on the inverting input of all operational amplifier N2, N3, N (n-1) and the luminous branch road of corresponding LED, the emitter of Q (n-1) link to each other, and can realize the LED multi-path current-sharing.
Claims (2)
1. high accuracy LED multi-path flow equalizing circuit, the luminous branch road of LED multi-path that comprises connection parallel with one another, LED is anodal in the luminous branch road of each paths of LEDs all is connected with the external power supply cathode output end, it is characterized in that: the LED negative pole of any branch road connects first end of first resistance (R1) in the luminous branch road of described LED multi-path, second end of first resistance (R1) connects first end of second resistance (R2), and second end of second resistance (R2) is connected with the external power supply cathode output end; The LED negative pole of other branch roads all connects the collector electrode of a triode in the luminous branch road of described LED multi-path, the emitter of this triode is connected with the external power supply cathode output end after all connecting a sampling resistor, and the resistance of all sampling resistors is all identical with described second resistance (R2); In addition, the base stage of all triodes links to each other with the output of an operational amplifier respectively, the in-phase input end of all operational amplifiers all links to each other with second end of described first resistance (R1), and the emitter of the triode on the inverting input of all operational amplifiers and the luminous branch road of corresponding LED links to each other.
2. high accuracy LED multi-path flow equalizing circuit according to claim 1 is characterized in that: be connected an electric capacity between the base stage of described triode and ground.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102750897A (en) * | 2012-07-12 | 2012-10-24 | 合肥华耀电子工业有限公司 | Simple test circuit for LED (light emitting diode) display module |
| CN102843838A (en) * | 2012-08-31 | 2012-12-26 | 上海遍发电子科技有限公司 | Multipath LED (Light Emitting Diode) current-sharing circuit and LED light |
| CN102858057A (en) * | 2012-08-10 | 2013-01-02 | 东莞芯成电子科技有限公司 | Current equalizing system for controlling each branch current of LED (light emitting diode) lamp circuit |
| CN103298222A (en) * | 2013-07-03 | 2013-09-11 | 上海顿格电子贸易有限公司 | Light-emitting diode (LED) multi-channel current-sharing circuit |
| CN103379695A (en) * | 2012-04-17 | 2013-10-30 | 立锜科技股份有限公司 | Driving circuit capable of improving utilization rate of LED apparatus, and relative constant current regulator |
| CN103596322A (en) * | 2012-08-16 | 2014-02-19 | 深圳市海洋王照明工程有限公司 | Constant current comparison circuit for LED driving circuit |
| CN105208730A (en) * | 2015-09-28 | 2015-12-30 | 无锡中感微电子股份有限公司 | LED drive circuit capable of achieving current matching |
| CN109061438A (en) * | 2018-07-17 | 2018-12-21 | 武汉精测电子集团股份有限公司 | A kind of multiple power supplies parallel current-sharing device and method for the detection of mould group |
| CN109804327A (en) * | 2017-04-19 | 2019-05-24 | 深圳市大疆创新科技有限公司 | Voltage regulator circuit and power supply circuit, remote controler with the voltage regulator circuit |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10329367A1 (en) * | 2003-03-28 | 2004-10-14 | Osram Opto Semiconductors Gmbh | LED chain for signaling arrangement, has converter circuit which forces predetermined current through LED chain independent of external influences |
| CN2826895Y (en) * | 2005-09-16 | 2006-10-11 | 谭泽民 | Constant current driver control circuit of color-changing LED lamp |
| CN101674693A (en) * | 2009-10-01 | 2010-03-17 | 英飞特电子（杭州）有限公司 | Multichannel constant-current control circuit applicable to LED driver |
| CN201467526U (en) * | 2009-06-09 | 2010-05-12 | 上海韦尔半导体股份有限公司 | Multi-channel white-light LED driver and LED illuminator |
| CN201780763U (en) * | 2010-07-30 | 2011-03-30 | 惠州Tcl移动通信有限公司 | Automatic light emitting diode (LED) brightness adjusting circuit of mobile terminal |
-
2011
- 2011-07-28 CN CN2011102184932A patent/CN102256421A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10329367A1 (en) * | 2003-03-28 | 2004-10-14 | Osram Opto Semiconductors Gmbh | LED chain for signaling arrangement, has converter circuit which forces predetermined current through LED chain independent of external influences |
| CN2826895Y (en) * | 2005-09-16 | 2006-10-11 | 谭泽民 | Constant current driver control circuit of color-changing LED lamp |
| CN201467526U (en) * | 2009-06-09 | 2010-05-12 | 上海韦尔半导体股份有限公司 | Multi-channel white-light LED driver and LED illuminator |
| CN101674693A (en) * | 2009-10-01 | 2010-03-17 | 英飞特电子（杭州）有限公司 | Multichannel constant-current control circuit applicable to LED driver |
| CN201780763U (en) * | 2010-07-30 | 2011-03-30 | 惠州Tcl移动通信有限公司 | Automatic light emitting diode (LED) brightness adjusting circuit of mobile terminal |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103379695B (en) * | 2012-04-17 | 2015-03-25 | 立锜科技股份有限公司 | Driving circuit capable of improving utilization rate of LED apparatus, and relative constant current regulator |
| CN103379695A (en) * | 2012-04-17 | 2013-10-30 | 立锜科技股份有限公司 | Driving circuit capable of improving utilization rate of LED apparatus, and relative constant current regulator |
| CN102750897A (en) * | 2012-07-12 | 2012-10-24 | 合肥华耀电子工业有限公司 | Simple test circuit for LED (light emitting diode) display module |
| CN102750897B (en) * | 2012-07-12 | 2015-02-11 | 合肥华耀电子工业有限公司 | Simple test circuit for LED (light emitting diode) display module |
| CN102858057B (en) * | 2012-08-10 | 2015-01-07 | 东莞芯成电子科技有限公司 | Current equalizing system for controlling each branch current of LED (light emitting diode) lamp circuit |
| CN102858057A (en) * | 2012-08-10 | 2013-01-02 | 东莞芯成电子科技有限公司 | Current equalizing system for controlling each branch current of LED (light emitting diode) lamp circuit |
| CN103596322A (en) * | 2012-08-16 | 2014-02-19 | 深圳市海洋王照明工程有限公司 | Constant current comparison circuit for LED driving circuit |
| CN103596322B (en) * | 2012-08-16 | 2017-07-14 | 深圳市海洋王照明工程有限公司 | A kind of constant current comparison circuit for LED drive circuit |
| CN102843838A (en) * | 2012-08-31 | 2012-12-26 | 上海遍发电子科技有限公司 | Multipath LED (Light Emitting Diode) current-sharing circuit and LED light |
| CN102843838B (en) * | 2012-08-31 | 2015-05-06 | 上海遍发电子科技有限公司 | Multipath LED (Light Emitting Diode) current-sharing circuit and LED light |
| CN103298222A (en) * | 2013-07-03 | 2013-09-11 | 上海顿格电子贸易有限公司 | Light-emitting diode (LED) multi-channel current-sharing circuit |
| CN105208730A (en) * | 2015-09-28 | 2015-12-30 | 无锡中感微电子股份有限公司 | LED drive circuit capable of achieving current matching |
| CN105208730B (en) * | 2015-09-28 | 2018-04-13 | 无锡中感微电子股份有限公司 | The LED drive circuit of currents match |
| CN109804327A (en) * | 2017-04-19 | 2019-05-24 | 深圳市大疆创新科技有限公司 | Voltage regulator circuit and power supply circuit, remote controler with the voltage regulator circuit |
| CN109804327B (en) * | 2017-04-19 | 2021-05-04 | 深圳市大疆创新科技有限公司 | Voltage stabilizing circuit, power supply circuit with same and remote controller |
| CN109061438A (en) * | 2018-07-17 | 2018-12-21 | 武汉精测电子集团股份有限公司 | A kind of multiple power supplies parallel current-sharing device and method for the detection of mould group |
| CN109061438B (en) * | 2018-07-17 | 2021-03-09 | 武汉精测电子集团股份有限公司 | Multi-path power supply parallel current equalizing device and method for module detection |
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Application publication date: 20111123 |