CN204425733U - For the supply power voltage regulating system of LED linear constant current circuit - Google Patents

For the supply power voltage regulating system of LED linear constant current circuit Download PDF

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Publication number
CN204425733U
CN204425733U CN201520108534.6U CN201520108534U CN204425733U CN 204425733 U CN204425733 U CN 204425733U CN 201520108534 U CN201520108534 U CN 201520108534U CN 204425733 U CN204425733 U CN 204425733U
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China
Prior art keywords
voltage
constant current
linear constant
circuit
lamp bead
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CN201520108534.6U
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Chinese (zh)
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王勇涛
楼俊山
孙超群
沈锦祥
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Zhejiang Shenghui Lighting Co Ltd
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Zhejiang Shenghui Lighting Co Ltd
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Abstract

The utility model embodiment provides a kind of supply power voltage regulating system for LED linear constant current circuit, by operational amplification circuit according to the voltage at LED lamp bead two ends in LED linear constant current circuit and default reference data voltage, generated error amplifying signal, then voltage feedback circuit is according to this error amplification signal, the duty ratio of adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment LED linear constant current circuit.Achieve the supply power voltage of LED linear constant current circuit and the change in voltage positive correlation of LED, thus avoid the circuit loss because the curent change in LED causes.

Description

For the supply power voltage regulating system of LED linear constant current circuit
Technical field
The utility model relates to a kind of technical field of LED illumination, particularly relates to a kind of supply power voltage regulating system for LED linear constant current circuit.
Background technology
The solid-state semiconductor device of LED (Light Emitting Diode, light-emitting diode) to be a kind of can be by electric energy conversion visible ray, it directly can be converted into light electricity.LED due to have energy-saving and environmental protection, can the lot of advantages such as light-operated, practical, stability is high, the response time is short, long-life, be widely used in various lighting field in the today of advocating low-carbon (LC) life.
Fig. 1 is the linear constant current circuit for LED in prior art, as shown in Figure 1, linear constant current circuit comprises N number of linear constant current unit, Fig. 1 is described for three-route constant current unit, by regulating the base voltage of field effect transistor in each linear constant current unit that field effect transistor can be made to be operated in linear zone, thus the voltage at LED lamp bead two ends in each linear constant current unit is made to reach the object of constant current with curent change.
But, the voltage Vout powered for linear constant current circuit in prior art is changeless, if less through the electric current of LED, in each linear constant current unit, the voltage at LED lamp bead two ends will reduce, accordingly, the voltage of LED lamp bead output will rise, and the loss of circuit can be made like this to increase.
Utility model content
The utility model provides a kind of supply power voltage regulating system for LED linear constant current circuit, if diminish with the electric current solved through LED in prior art, and the voltage rise of LED lamp bead output, thus the technological deficiency that circuit loss is increased.
According to first aspect of the present utility model, a kind of supply power voltage regulating system for LED linear constant current circuit is provided, comprises: linear constant current circuit, also comprise: operational amplification circuit and voltage feedback circuit;
Wherein, described operational amplification circuit is connected with described linear constant current circuit and described voltage feedback circuit respectively, and described voltage feedback circuit is connected with described linear constant current circuit;
Described operational amplification circuit, for according to the voltage at LED lamp bead two ends in described linear constant current circuit and the reference data voltage preset, generated error amplifying signal,
Described voltage feedback circuit, for according to described error amplification signal, the duty ratio of adjustment pulse width modulation control chip output signal, and then adjust the supply power voltage of described linear constant current circuit, to make the change in voltage positive correlation of described supply power voltage and described LED lamp bead;
Wherein, described linear constant current circuit comprises N number of linear constant current unit, and each linear constant current unit comprises: LED lamp bead, linear block and resistance, wherein, the anode of described LED lamp bead connects supply power voltage, and the negative electrode of described LED lamp bead is by described linear block and described grounding through resistance;
If described N equals 1, described operational amplification circuit specifically for:
According to voltage and the described reference data voltage at LED lamp bead two ends in described linear constant current unit, generated error amplifying signal.
System as above, if described N is greater than 1, described system also comprises: voltage comparator circuit,
Described voltage comparator circuit, obtains minimum voltage in the voltage for LED lamp bead two ends all from described linear constant current circuit;
Described operational amplification circuit specifically for: according to described minimum voltage and described reference data voltage, generated error amplifying signal.
System as above, described voltage comparator circuit specifically for:
Detect the magnitude of voltage at each linear constant current unit neutral line module two ends;
The magnitude of voltage at more all linear block two ends obtains maximum voltage.
System as above, described voltage comparator circuit specifically for:
Detect the magnitude of voltage at LED lamp bead two ends in each linear constant current unit;
The magnitude of voltage at more all LED lamp bead two ends obtains minimum voltage.
System as above, described voltage comparator circuit specifically comprises:
The diode identical with described N number of linear constant current element number, the input signal of each diode cathode is the output voltage of LED lamp bead in each linear constant current unit, the anode of each diode is connected to described operational amplification circuit, and the anode of described each diode connects power supply by resistance.
System as above, described voltage feedback circuit comprises:
Triode (Q1), the first reference voltage source (U1) and optocoupler, wherein,
The base stage of described triode (Q1) connects the error amplification signal of described operational amplification circuit output, the emitter of described triode (Q1) is by resistance (R3) ground connection, the collector electrode of described triode (Q1) is connected to described first reference voltage source (U1), and described collector electrode is connected to the supply power voltage of described LED linear constant current circuit by resistance (R1), and by resistance (R2) ground connection, the plus earth of described first reference voltage source (U1), the negative electrode of described first reference voltage source (U1) is connected to described optocoupler, to be adjusted the duty ratio of described pulse width modulation control chip output signal by described optocoupler.
System as above, described operational amplification circuit comprises:
First operational amplifier (UIA) and the second operational amplifier (UIB),
Wherein, the normal phase input end of described first operational amplifier (UIA) connects described reference data voltage by resistance (R7), the inverting input of described first operational amplifier (UIA) connects the output of LED lamp bead in described LED linear constant current circuit by resistance (R5), and the inverting input of described first operational amplifier (UIA) is connected to the normal phase input end of described second operational amplifier (UIB) by resistance (R4) and electric capacity (C1), the output of described first operational amplifier (UIA) is connected to the normal phase input end of described second operational amplifier (UIB), the inverting input of described second operational amplifier is connected to the emitter of described triode (Q1), the output of described second operational amplifier is connected to the base stage of described triode (Q1).
System as above, described operational amplification circuit comprises:
Second reference voltage source (U2)
Described second reference voltage source (U2) connects the output of LED lamp bead in described LED linear constant current circuit by resistance (R8), and described second reference voltage source (U2) is connected to the base stage of described triode (Q1) by electric capacity (C2) and resistance (R9), the negative electrode of described second reference voltage source (U2) connects power supply, the plus earth of described second reference voltage source (U2) by resistance (R10).
The supply power voltage regulating system for LED linear constant current circuit that the utility model embodiment provides, by operational amplification circuit according to the voltage at LED lamp bead two ends in LED linear constant current circuit and default reference data voltage, generated error amplifying signal, then voltage feedback circuit is according to this error amplification signal, the duty ratio of adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment LED linear constant current circuit.Achieve the supply power voltage of LED linear constant current circuit and the change in voltage positive correlation of LED, thus avoid the circuit loss because the curent change in LED causes.
Accompanying drawing explanation
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is embodiments more of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the linear constant current circuit for LED in prior art;
Fig. 2 is the structural representation one of the utility model for the supply power voltage regulating system of LED linear constant current circuit;
Fig. 3 is the structural representation two of the utility model for the supply power voltage regulating system of LED linear constant current circuit;
Fig. 4 is the circuit diagram of the utility model for voltage feedback circuit in the supply power voltage regulating system of LED linear constant current circuit;
Fig. 5 regulates the fundamental diagram of the supply power voltage of LED linear constant current circuit for the voltage feedback circuit shown in application drawing 4;
Fig. 6 is the circuit diagram one of the utility model for the supply power voltage regulating system of LED linear constant current circuit;
Fig. 7 is the circuit diagram two of the utility model for the supply power voltage regulating system of LED linear constant current circuit.
Embodiment
For making the object of the utility model embodiment, technical scheme and advantage clearly, below in conjunction with the accompanying drawing in the utility model embodiment, technical scheme in the utility model embodiment is clearly and completely described, obviously, described embodiment is the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
Fig. 2 is the structural representation one of the utility model for the supply power voltage regulating system of LED linear constant current circuit, and as shown in Figure 2, this system comprises: linear constant current circuit 11, operational amplification circuit 12 and voltage feedback circuit 13;
Wherein, operational amplification circuit 12 is connected with linear constant current circuit 11 and voltage feedback circuit 13 respectively, and voltage feedback circuit 13 is connected with linear constant current circuit 11;
Operational amplification circuit 12, for according to the voltage at LED lamp bead two ends in linear constant current circuit 11 and the reference data voltage preset, generated error amplifying signal,
Voltage feedback circuit 13, for according to this error amplification signal, adjusts the duty ratio of pulse width modulation control chip output signal, and then the supply power voltage of adjustment linear constant current circuit 11, to make the change in voltage positive correlation of this supply power voltage and LED lamp bead.
Particularly, the input of the output concatenation operation amplifying circuit 12 of LED lamp bead in linear constant current circuit 11, when the electric current flowing through LED lamp bead in linear constant current circuit 11 diminishes, the voltage at LED lamp bead two ends can diminish, now, operational amplification circuit 12 is according to the voltage at LED lamp bead two ends and default reference data voltage, the error amplification signal sent to voltage feedback circuit 13 can diminish, thus reduced by the duty ratio that voltage feedback circuit 13 makes pulse width modulation control chip output signal, cause the supply power voltage of linear constant current circuit 11 to reduce; When the ER effect flowing through LED lamp bead in linear constant current circuit 11 is large, the voltage at LED lamp bead two ends can become large, now, operational amplification circuit 12 is according to the voltage at LED lamp bead two ends and default reference data voltage, the error amplification signal sent to voltage feedback circuit 13 can become large, thus increased by the duty ratio that voltage feedback circuit 13 makes pulse width modulation control chip output signal, cause the supply power voltage of linear constant current circuit 11 to raise, thus make the change in voltage positive correlation of this supply power voltage and LED lamp bead.
The supply power voltage regulating system for LED linear constant current circuit that the present embodiment provides, by operational amplification circuit according to the voltage at LED lamp bead two ends in LED linear constant current circuit and default reference data voltage, generated error amplifying signal, then voltage feedback circuit is according to this error amplification signal, the duty ratio of adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment LED linear constant current circuit.Achieve the supply power voltage of LED linear constant current circuit and the change in voltage positive correlation of LED, thus avoid the circuit loss because the curent change in LED causes.
LED linear constant current circuit shown in Figure 1 is known, linear constant current circuit 11 comprises N number of linear constant current unit, each linear constant current unit comprises: LED lamp bead, linear block and resistance, wherein, the anode of LED lamp bead connects supply power voltage, the negative electrode of LED lamp bead is by linear block and grounding through resistance, wherein, linear block comprises: field effect transistor, triode and for making linear constant current cell operation at the circuit of linear zone, and the linear block shown in Fig. 1 is illustrate meaning explanation with field effect transistor.
Particularly, if N equals 1, namely a linear constant current unit is only comprised in linear constant current circuit 11, that is a LED lamp bead is only had, the structural representation of the corresponding supply power voltage regulating system for this linear constant current circuit as shown in Figure 2, wherein, operational amplification circuit 12 specifically for: according to voltage and the reference data voltage at LED lamp bead two ends in linear constant current unit, generated error amplifying signal.
If N is greater than 1, namely two linear constant current unit are at least comprised in linear constant current circuit 11, that is two LED lamp bead are had at least, the structural representation of the corresponding supply power voltage regulating system for this linear constant current circuit as shown in Figure 3, Fig. 3 is the structural representation two of the utility model for the supply power voltage regulating system of LED linear constant current circuit, as shown in Figure 3, based on embodiment illustrated in fig. 2, this supply power voltage regulating system also comprises: voltage comparator circuit 14, wherein, voltage comparator circuit 14 is connected with linear constant current circuit 11 and operational amplification circuit 12 respectively, wherein,
Voltage comparator circuit 14, obtains minimum voltage in the voltage for LED lamp bead two ends all from linear constant current circuit 11;
Operational amplification circuit 12 specifically for: according to described minimum voltage and described reference data voltage, generated error amplifying signal.
Particularly, voltage comparator circuit 14 can in several ways from linear constant current circuit 11 all LED lamp bead two ends voltage in obtain minimum voltage, be exemplified below:
Situation one, voltage comparator circuit 14 specifically for:
Detect the magnitude of voltage at each linear constant current unit neutral line module two ends;
The magnitude of voltage at more all linear block two ends obtains maximum voltage.
Situation two, voltage comparator circuit 14 specifically for:
Detect the magnitude of voltage at LED lamp bead two ends in each linear constant current unit;
The magnitude of voltage at more all LED lamp bead two ends obtains minimum voltage.
The minimum voltage got in the present embodiment in the voltage at all LED lamp bead two ends is to ensure that each paths of LEDs lamp pearl electric current can reach maximum, if do not get minimum value can not meet all LED lamp bead required voltages by the supply power voltage for LED linear constant current circuit after adjustment.
For the voltage feedback circuit 13 in above-mentioned illustrated embodiment, its function is the duty ratio that the error amplification signal fed back according to operational amplification circuit 12 changes pulse width modulation control chip output signal, thus the supply power voltage of adjustment linear constant current circuit 11, those skilled in the art can apply the different circuit diagram of different electronic device design to realize above-mentioned functions.Optimally, Fig. 4 is the circuit diagram of the utility model for voltage feedback circuit in the supply power voltage regulating system of LED linear constant current circuit, Fig. 5 regulates the fundamental diagram of the supply power voltage of LED linear constant current circuit for the voltage feedback circuit shown in application drawing 4, see Fig. 4 and Fig. 5, be described as follows:
This voltage feedback circuit specifically comprises: triode (Q1), the components and parts such as the first reference voltage source (U1) and optocoupler, wherein, the error amplification signal of base stage concatenation operation amplifying circuit 12 output of triode (Q1), the emitter of triode (Q1) is by resistance (R3) ground connection, the collector electrode of triode (Q1) is connected to the input 1 in the first reference voltage source (U1), and collector electrode is connected to the supply power voltage (Vout) of linear constant current circuit 11 by resistance (R1), and by resistance (R2) ground connection, anode 3 ground connection of the first reference voltage source (U1), the negative electrode 2 of the first reference voltage source (U1) is connected to optocoupler, thus the duty ratio of pulse width modulation control chip output signal is adjusted by optocoupler.
Output voltage adjustment process is particularly: when the electric current flowing through LED lamp bead in linear constant current circuit 11 diminishes, the voltage at LED lamp bead two ends can diminish, now, operational amplification circuit 12 is according to the voltage at LED lamp bead two ends and default reference data voltage, the error amplification signal that the base stage of triode (Q1) sends in voltage feedback circuit 13 can diminish, the voltage at V2 place reduces, the voltage at V1 place raises, the voltage at negative electrode 2 place of the first reference voltage source (U1) is made to reduce (V3 place), the reduction of V3 place voltage can make the electric current flowing through optocoupler increase, thus the 2 pin voltages of adjustment pulse width modulation control chip NCP1251, the duty ratio of the pulse width modulating signal causing 6 pin of NCP1251 to export reduces, thus the supply power voltage of linear constant current circuit 11 is reduced.
When the ER effect flowing through LED lamp bead in linear constant current circuit 11 is large, the voltage at LED lamp bead two ends can become large, now, operational amplification circuit 12 is according to the voltage at LED lamp bead two ends and default reference data voltage, the error amplification signal that the base stage of triode (Q1) sends in voltage feedback circuit 13 can become large, the voltage at V2 place raises, the voltage at V1 place reduces, the voltage at negative electrode 2 place of the first reference voltage source (U1) is made to raise (V3 place), the rising of V3 place voltage can make the electric current flowing through optocoupler reduce, thus the 2 pin voltages of adjustment pulse width modulation control chip NCP1251, the duty ratio of the pulse width modulating signal causing 6 pin of NCP1251 to export increases, thus the supply power voltage of linear constant current circuit 11 is raised.
In sum, the duty ratio that the error amplification signal that voltage feedback circuit 13 feeds back according to operational amplification circuit 12 is outputed signal by triode and optocoupler change pulse width modulation control chip, thus the supply power voltage of adjustment linear constant current circuit 11, thus make the change in voltage positive correlation of this supply power voltage and LED lamp bead.
The supply power voltage regulating system for LED linear constant current circuit that the present embodiment provides, by operational amplification circuit according to the voltage at LED lamp bead two ends in LED linear constant current circuit and default reference data voltage, generated error amplifying signal, then voltage feedback circuit is according to this error amplification signal, by the duty ratio that triode and optocoupler adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment LED linear constant current circuit.Achieve the supply power voltage of LED linear constant current circuit and the change in voltage positive correlation of LED, thus avoid the circuit loss because the curent change in LED causes.
For the operational amplification circuit 12 in above-mentioned illustrated embodiment, its function is according to the voltage at LED lamp bead two ends in linear constant current circuit and the reference data voltage preset, generated error amplifying signal is sent to voltage feedback circuit 13, to make voltage feedback circuit 13 according to this error amplification signal, the duty ratio of adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment linear constant current circuit.Those skilled in the art can apply the different circuit diagram of different electronic device design in order to the function realizing above-mentioned operational amplification circuit 12.
In order to clearer description is used for the supply power voltage regulating system of this linear constant current circuit, for Fig. 6 with to be embodiment illustrated in fig. 7ly described as follows:
Fig. 6 is the circuit diagram one of the utility model for the supply power voltage regulating system of LED linear constant current circuit, as shown in Figure 6, in the present embodiment linear constant current circuit adopt the linear constant current circuit shown in Fig. 1, specifically comprise three linear constant current unit, have a LED lamp bead in each linear constant current unit, the voltage comparator circuit 14 in embodiment illustrated in fig. 6 specifically comprises:
Three diodes, with three linear constant current unit one_to_one corresponding, the input signal of each diode cathode is the voltage of LED lamp bead output in each linear constant current unit, the anode of each diode is connected to operational amplification circuit 12, and the anode of each diode connects power supply (Vcc) by resistance (R6).By the conducting effect of the diode in this voltage comparator circuit 14, the voltage of other LED lamp bead can drag down by the lamp pearl that in linear constant current circuit, LED lamp bead output end voltage is minimum, namely ensures that the minimum voltage in the output end voltage of all LED lamp bead is delivered to operational amplification circuit 12.
Operational amplification circuit 12 in embodiment illustrated in fig. 6 specifically comprises:
First operational amplifier (UIA) and the second operational amplifier (UIB),
Wherein, the normal phase input end of the first operational amplifier (UIA) connects reference data voltage by resistance (R7), the inverting input of the first operational amplifier (UIA) passes through the output voltage of LED lamp bead in resistance (R5) connecting linear constant-current circuit, it should be noted that, when being only a linear constant current unit in linear constant current circuit, the inverting input of the first operational amplifier (UIA) connects the minimum voltage of the LED lamp bead output that voltage comparator circuit exports by resistance (R5), the inverting input of the first operational amplifier (UIA) is connected to the normal phase input end of the second operational amplifier (UIB) by resistance (R4) and electric capacity (C1), the output of the first operational amplifier (UIA) is connected to the normal phase input end of the second operational amplifier (UIB), the inverting input of the second operational amplifier is connected to the emitter of triode (Q1) in voltage feedback circuit 13, the output of the second operational amplifier is connected to the base stage of triode (Q1).
Voltage feedback circuit 13 in embodiment illustrated in fig. 6 is specifically adopted as the circuit shown in above-described embodiment Fig. 4, and its composition structure and the concrete embodiment shown in Figure 4 of operation principle, repeat no more herein.
The adjustment process concrete to supply power voltage (Vout) embodiment illustrated in fig. 6 is as follows: when LED lamp bead electric current reduces, the voltage of resistance (R5) input can raise, the voltage of the first operational amplifier (UIA) output can reduce, the output voltage of the second operational amplifier (UIB) can reduce, voltage V2 on resistance (R3) also can reduce, the voltage at V1 place can rise, the rising of V1 can make the electric current flowing through optocoupler increase, the duty ratio that pulse width modulation control chip is outputed signal reduces, thus supply power voltage is reduced.Otherwise, when LED lamp bead electric current increases, the voltage of resistance (R5) input can reduce, the voltage of the first operational amplifier (UIA) output can increase, the output voltage of the second operational amplifier (UIB) can increase, voltage V2 on resistance (R3) also can increase, the voltage at V1 place can reduce, the reduction of V1 can make the electric current flowing through optocoupler reduce, the duty ratio that pulse width modulation control chip is outputed signal increases, thus supply power voltage is raised.
The supply power voltage regulating system for LED linear constant current circuit that the present embodiment provides, the minimum voltage of the LED lamp bead output exported according to voltage comparator circuit by two-stage calculation amplifier and default reference data voltage, generated error amplifying signal, then voltage feedback circuit is according to this error amplification signal, by the duty ratio that triode and optocoupler adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment LED linear constant current circuit.Achieve the supply power voltage of LED linear constant current circuit and the change in voltage positive correlation of LED, thus avoid the circuit loss because the curent change in LED causes.
Fig. 7 is the circuit diagram two of the utility model for the supply power voltage regulating system of LED linear constant current circuit, as shown in Figure 7, voltage comparator circuit 14 in embodiment illustrated in fig. 7 and voltage feedback circuit 13 specifically adopt the circuit shown in Fig. 6, its composition structure and the concrete embodiment shown in Figure 6 of operation principle, repeat no more herein.
Operational amplification circuit 12 in embodiment illustrated in fig. 7 specifically comprises: the second reference voltage source (U2), wherein, second reference voltage source (U2) connects LED lamp bead output in LED linear constant current circuit by resistance (R8), and the second reference voltage source (U2) is connected to the base stage of triode (Q1) by electric capacity (C2) and resistance (R9), the negative electrode of the second reference voltage source (U2) connects power supply (Vcc), the plus earth of the second reference voltage source (U2) by resistance (R10).Second reference voltage source (U2) is according to the minimum voltage generated error amplifying signal of LED lamp bead output in the reference data voltage of self and linear constant current circuit.
The adjustment process concrete to supply power voltage (Vout) embodiment illustrated in fig. 7 is as follows: when LED lamp bead electric current reduces, the voltage of resistance (R8) input can raise, the output voltage V4 of the second reference voltage source (U2) can reduce, voltage V2 on resistance (R3) also can reduce, the voltage at V1 place can rise, the rising of V1 can make the electric current flowing through optocoupler increase, the duty ratio that pulse width modulation control chip is outputed signal reduces, thus supply power voltage is reduced.Otherwise, when LED lamp bead electric current increases, the voltage of resistance (R8) input can reduce, the output voltage V4 of the second reference voltage source (U2) can increase, voltage V2 on resistance (R3) also can increase, and the voltage at V1 place can reduce, and the reduction of V1 can make the electric current flowing through optocoupler reduce, the duty ratio that pulse width modulation control chip is outputed signal increases, thus supply power voltage is raised.
The supply power voltage regulating system for LED linear constant current circuit that the present embodiment provides, the minimum voltage of the LED lamp bead output exported according to the reference data voltage of self and voltage comparator circuit by reference voltage source, generated error amplifying signal, then voltage feedback circuit is according to this error amplification signal, by the duty ratio that triode and optocoupler adjustment pulse width modulation control chip output signal, and then the supply power voltage of adjustment LED linear constant current circuit.Achieve the supply power voltage of LED linear constant current circuit and the change in voltage positive correlation of LED, thus avoid the circuit loss because the curent change in LED causes.
One of ordinary skill in the art will appreciate that: all or part of step realizing said method embodiment can have been come by the hardware that program command is relevant, aforesaid program can be stored in a computer read/write memory medium, this program, when performing, performs the step comprising said method embodiment; And aforesaid storage medium comprises: ROM, RAM, magnetic disc or CD etc. various can be program code stored medium.
Last it is noted that above each embodiment is only in order to illustrate the technical solution of the utility model, be not intended to limit; Although be described in detail the utility model with reference to foregoing embodiments, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein some or all of technical characteristic; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of each embodiment technical scheme of the utility model.

Claims (8)

1. for a supply power voltage regulating system for LED linear constant current circuit, comprising: linear constant current circuit, it is characterized in that, also comprise: operational amplification circuit and voltage feedback circuit;
Wherein, described operational amplification circuit is connected with described linear constant current circuit and described voltage feedback circuit respectively, and described voltage feedback circuit is connected with described linear constant current circuit;
Described operational amplification circuit, for according to the voltage at LED lamp bead two ends in described linear constant current circuit and the reference data voltage preset, generated error amplifying signal,
Described voltage feedback circuit, for according to described error amplification signal, the duty ratio of adjustment pulse width modulation control chip output signal, and then adjust the supply power voltage of described linear constant current circuit, to make the change in voltage positive correlation of described supply power voltage and described LED lamp bead;
Wherein, described linear constant current circuit comprises N number of linear constant current unit, and each linear constant current unit comprises: LED lamp bead, linear block and resistance, wherein, the anode of described LED lamp bead connects supply power voltage, and the negative electrode of described LED lamp bead is by described linear block and described grounding through resistance;
If described N equals 1, described operational amplification circuit specifically for:
According to voltage and the described reference data voltage at LED lamp bead two ends in described linear constant current unit, generated error amplifying signal.
2. system according to claim 1, is characterized in that,
If described N is greater than 1, described system also comprises: voltage comparator circuit,
Described voltage comparator circuit, obtains minimum voltage in the voltage for LED lamp bead two ends all from described linear constant current circuit;
Described operational amplification circuit specifically for: according to described minimum voltage and described reference data voltage, generated error amplifying signal.
3. system according to claim 2, is characterized in that, described voltage comparator circuit specifically for:
Detect the magnitude of voltage at each linear constant current unit neutral line module two ends;
The magnitude of voltage at more all linear block two ends obtains maximum voltage.
4. system according to claim 2, is characterized in that, described voltage comparator circuit specifically for:
Detect the magnitude of voltage at LED lamp bead two ends in each linear constant current unit;
The magnitude of voltage at more all LED lamp bead two ends obtains minimum voltage.
5. system according to claim 2, is characterized in that, described voltage comparator circuit specifically comprises:
The diode identical with described N number of linear constant current element number, the input signal of each diode cathode is the output voltage of LED lamp bead in each linear constant current unit, the anode of each diode is connected to described operational amplification circuit, and the anode of described each diode connects power supply by resistance.
6., according to the arbitrary described system of claim 1-5, it is characterized in that, described voltage feedback circuit comprises:
Triode (Q1), the first reference voltage source (U1) and optocoupler, wherein,
The base stage of described triode (Q1) connects the error amplification signal of described operational amplification circuit output, the emitter of described triode (Q1) is by resistance (R3) ground connection, the collector electrode of described triode (Q1) is connected to described first reference voltage source (U1), and described collector electrode is connected to the supply power voltage of described LED linear constant current circuit by resistance (R1), and by resistance (R2) ground connection, the plus earth of described first reference voltage source (U1), the negative electrode of described first reference voltage source (U1) is connected to described optocoupler, to be adjusted the duty ratio of described pulse width modulation control chip output signal by described optocoupler.
7. system according to claim 6, is characterized in that, described operational amplification circuit comprises:
First operational amplifier (UIA) and the second operational amplifier (UIB),
Wherein, the normal phase input end of described first operational amplifier (UIA) connects described reference data voltage by resistance (R7), the inverting input of described first operational amplifier (UIA) connects the output of LED lamp bead in described LED linear constant current circuit by resistance (R5), and the inverting input of described first operational amplifier (UIA) is connected to the normal phase input end of described second operational amplifier (UIB) by resistance (R4) and electric capacity (C1), the output of described first operational amplifier (UIA) is connected to the normal phase input end of described second operational amplifier (UIB), the inverting input of described second operational amplifier is connected to the emitter of described triode (Q1), the output of described second operational amplifier is connected to the base stage of described triode (Q1).
8. system according to claim 6, is characterized in that, described operational amplification circuit comprises:
Second reference voltage source (U2)
Described second reference voltage source (U2) connects the output of LED lamp bead in described LED linear constant current circuit by resistance (R8), and described second reference voltage source (U2) is connected to the base stage of described triode (Q1) by electric capacity (C2) and resistance (R9), the negative electrode of described second reference voltage source (U2) connects power supply, the plus earth of described second reference voltage source (U2) by resistance (R10).
CN201520108534.6U 2015-02-13 2015-02-13 For the supply power voltage regulating system of LED linear constant current circuit Expired - Fee Related CN204425733U (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104717804A (en) * 2015-02-13 2015-06-17 浙江生辉照明有限公司 Supply voltage regulating system for LED lamp linear constant-current circuit
CN111200892B (en) * 2020-02-28 2023-08-29 深圳市晟碟半导体有限公司 LED control device, circuit and control method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104717804A (en) * 2015-02-13 2015-06-17 浙江生辉照明有限公司 Supply voltage regulating system for LED lamp linear constant-current circuit
CN111200892B (en) * 2020-02-28 2023-08-29 深圳市晟碟半导体有限公司 LED control device, circuit and control method thereof

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