CN203827587U - Large power LED driving circuit - Google Patents
Large power LED driving circuit Download PDFInfo
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- CN203827587U CN203827587U CN201420251828.XU CN201420251828U CN203827587U CN 203827587 U CN203827587 U CN 203827587U CN 201420251828 U CN201420251828 U CN 201420251828U CN 203827587 U CN203827587 U CN 203827587U
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Abstract
The utility mode discloses a large power LED driving circuit. The large power LED driving circuit comprises an MCU control unit and a single-end fly-back switch power source, the large power LED driving circuit is characterized by comprising a voltage-controlled constant current source circuit, wherein a PWM output port of the MCU control unit is connected with the single-end fly-back switch power source, a brightness control voltage output port of the MCU control unit is connected with the voltage-controlled constant current source circuit, and an LED current sampling port of the voltage-controlled constant current source circuit is connected with the MCU control unit. The driving circuit employs the switch power source as a first level for control and employs a voltage-controlled constant current source as a second level for control, advantages of the two are integrated, efficiency and control precision are both guaranteed, direct power supply through a commercial power can be realized, two-level driving is realized, a safety level is high, and an LED lamp having an expensive price is not liable to damage.
Description
Technical field
The utility model relates to a kind of drive circuit, particularly powerful Led drive circuit.
Background technology
LED be acknowledged as green the 4th generation light source, be a kind of solid cold light source, there is the plurality of advantages such as efficient, life-span length, safety and environmental protection, volume are little, high reliability, fast response time.Reach at present same illuminating effect, the power consumption of LED is approximately 1/10 of incandescent lamp, 1/2 of fluorescent lamp.The development that a lot of countries and regions are put into effect various support on policy LED industries in succession, can become the important component part of national important industry to this industry, breeding huge business opportunity.LED drive circuit is most important concerning LED, and LED brightness adjustment control can be energy-conservation, and the driving of high-brightness white-light LED and light modulation are the focuses of Recent study.Switching Power Supply is current comparatively conventional drive circuit, but the actual of Switching Power Supply FEEDBACK CONTROL is output voltage, and output current control is not too easily accomplished accurately, and simplex switch power supply control fragile LED lamp while having deviation; The problem that linear circuit efficiency is not high.
Summary of the invention
Technical problem to be solved in the utility model is how to improve drive circuit output current control precision, reduces the technical problem that Led lamp is damaged.
In order to solve the problems of the technologies described above, the utility model has designed a kind of high-power LED drive circuit, comprise MCU control unit, single-end flyback switching power supply, characterized by further comprising controlled constant-current source circuit, the PWM delivery outlet of described MCU control unit is connected with single-end flyback switching power supply, described MCU control unit brilliance control voltage output be connected with controlled constant-current source circuit, the LED current sample port of controlled constant-current source circuit is connected with MCU control unit.
Described high-power LED drive circuit; it is characterized in that described single-end flyback switching power supply is by transformer T1, switching tube Q1, diode D1, diode D2, capacitor C 1; capacitor C 2 forms; primary coil one end of described transformer T1 is extremely connected with the D of switching tube Q1; other end end is connected with ac input end; the S utmost point of switching tube Q1 is connected with ac input end, and the G of switching tube Q1 is connected with the PWM delivery outlet of MCU control unit after extremely first connecing buffer circuit; The anode of diode D1 and diode D2 is connected with the secondary coil of transformer T1; The negative electrode of diode D1 connects LED load; Series resistor R3 ground connection again after the negative electrode connecting resistance R1 of diode D2.
Described high-power LED drive circuit, is characterized in that described controlled constant-current source circuit comprises operational amplifier U1, operational amplifier U2, power tube Q2, and resistance R 12 one end are connected with resistance R 8 with the S utmost point of power tube Q2, other end ground connection; Resistance R 8 is connected with the in-phase input end of operational amplifier U2; Resistance R 7 one end ground connection, the inverting input of other end connecting resistance R5 and operational amplifier U2; The output of resistance R 5 another termination operational amplifier U2, resistance R 10 one end ground connection, the output of another termination operational amplifier U2, realizes LED current sample, and the output of operational amplifier U2 is connected with MCU control unit as the LED current sample port of controlled constant-current source circuit; After the output termination R4 of operational amplifier U2, be connected with the inverting input of operational amplifier U1, MCU control unit brilliance control voltage output connecting resistance R6 after be connected with the in-phase input end of operational amplifier U1 with resistance R 9 respectively, the output of operational amplifier U1 is connected with the G utmost point of power tube Q2, and the S utmost point of power tube Q2 connects LED load.
Described high-power LED drive circuit, characterized by further comprising overvoltage crowbar, and described overvoltage crowbar comprises TL431, the negative electrode of described TL431 with after connecting resistance R2, be connected with the negative electrode of diode D2, the plus earth of TL431; The reference utmost point of TL431 is connected with the tie point of resistance R 3 with resistance R 1; Also increased logical AND gate, the negative electrode of described PWM delivery outlet and TL431 is as the input of logical AND gate, and the negative electrode of PWM delivery outlet and TL431 is done to be input to isolation drive after logic and operation again, then is connected with the G utmost point of switching tube Q1.
Enforcement the utlity model has following beneficial effect: drive circuit adopts Switching Power Supply as the first order of controlling, pressure-controlled constant-current source is as second utmost point of controlling, combine the two advantage, all guaranteed in efficiency and control precision, and can directly be powered by civil power, two-stage drive, safe, the LED lamp that not fragile price is higher.
Brief description of the drawings
Fig. 1 is that one of the present utility model is specifically implemented schematic diagram.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtaining under creative work prerequisite, all belong to the scope of the utility model protection.
Fig. 1 is that one of the present utility model is specifically implemented schematic diagram; MCU control unit is selected single-chip microcomputer STC89C51; single-end flyback switching power supply is by transformer T1, switching tube Q1, diode D1, diode D2, capacitor C 1; capacitor C 2 forms; primary coil one end of transformer T1 is extremely connected with the D of switching tube Q1; other end end is connected with ac input end; the S utmost point of switching tube Q1 is connected with ac input end, and the G of switching tube Q1 is connected with the PWM delivery outlet of MCU control unit after extremely first connecing buffer circuit; The anode of diode D1 and diode D2 is connected with the secondary coil of transformer T1; The negative electrode of diode D1 connects LED load; Series resistor R3 ground connection again after the negative electrode connecting resistance R1 of diode D2.
Controlled constant-current source circuit comprises operational amplifier U1, operational amplifier U2, power tube Q2, and resistance R 12 one end are connected with resistance R 8 with the S utmost point of power tube Q2, other end ground connection; Resistance R 8 is connected with the in-phase input end of operational amplifier U2; Resistance R 7 one end ground connection, the inverting input of other end connecting resistance R5 and operational amplifier U2; The output of resistance R 5 another termination operational amplifier U2, resistance R 10 one end ground connection, the output of another termination operational amplifier U2, realizes LED current sample, and the output of operational amplifier U2 is connected with MCU control unit as the LED current sample port of controlled constant-current source circuit; After the output termination R4 of operational amplifier U2, be connected with the inverting input of operational amplifier U1, MCU control unit brilliance control voltage output connecting resistance R6 after be connected with the in-phase input end of operational amplifier U1 with resistance R 9 respectively, the output of operational amplifier U1 is connected with the G utmost point of power tube Q2, and the S utmost point of power tube Q2 connects LED load.
Overvoltage crowbar, described overvoltage crowbar comprises TL431, the negative electrode of described TL431 with after connecting resistance R2, be connected with the negative electrode of diode D2, the plus earth of TL431; The reference utmost point of TL431 is connected with the tie point of resistance R 3 with resistance R 1; Also increased logical AND gate, the negative electrode of described PWM delivery outlet and TL431 is as the input of logical AND gate, and the negative electrode of PWM delivery outlet and TL431 is done to be input to isolation drive after logic and operation again, then is connected with the G utmost point of switching tube Q1.
In the time that needs change LED load brightness variation, STC89C51, according to user's setting, maybe can pass through external luminance sensor, automatically obtains current required brightness setting; STC89C51 arranges and produces a corresponding brilliance control voltage according to brightness.Brilliance control voltage is added in the in-phase input end of operational amplifier U1, and the reverse input end of operational amplifier U1 is the current signal of the LED that obtains through operational amplifier U2, and resistance R 12 is current sense resistor.The output voltage of operational amplifier U1 is the control voltage of power tube Q2, known by the empty short concept of operational amplifier, the reverse input voltage of operational amplifier U1 will equal the voltage on its positive input, electric current while namely stablizing in resistance R 12 is subject to the control of brilliance control voltage, and does not change with the variation of load.The brightness that STC89C51 obtains according to it also produces a pwm signal when generation one corresponding brilliance control voltage is set, signal phase on this pwm signal and TL431 with after remove the switch of control switch pipe Q1, then single-chip microcomputer is according to the LED current signal obtaining, change the duty ratio of pwm signal, change the output voltage of Switching Power Supply, also the input voltage that changes constant-current source reduces the voltage on power tube Q2, make it in the situation that output current is constant, be operated in adjustable resistance district or close to adjustable resistance district, to raise the efficiency.TL431 is three end adjustable shunt benchmark, and the existence of TL431 and respective electrical phase thereof is here the maximum output voltage for limit switch power supply, the fail safe that further improves system.
Above disclosed is only a kind of embodiment of the utility model, certainly can not limit with this interest field of the utility model, one of ordinary skill in the art will appreciate that all or part of flow process that realizes above-described embodiment, and the equivalent variations of doing according to the utility model claim, still belong to the scope that utility model contains.
Claims (4)
1. a high-power LED drive circuit, comprise MCU control unit, single-end flyback switching power supply, characterized by further comprising controlled constant-current source circuit, the PWM delivery outlet of described MCU control unit is connected with single-end flyback switching power supply, described MCU control unit brilliance control voltage output be connected with controlled constant-current source circuit, the LED current sample port of controlled constant-current source circuit is connected with MCU control unit.
2. high-power LED drive circuit according to claim 1; it is characterized in that described single-end flyback switching power supply is by transformer T1, switching tube Q1, diode D1, diode D2, capacitor C 1; capacitor C 2 forms; primary coil one end of described transformer T1 is extremely connected with the D of switching tube Q1; the other end is connected with ac input end; the S utmost point of switching tube Q1 is connected with ac input end, and the G of switching tube Q1 is connected with the PWM delivery outlet of MCU control unit after extremely first connecing buffer circuit; The anode of diode D1 and diode D2 is connected with the secondary coil of transformer T1; The negative electrode of diode D1 connects LED load; Series resistor R3 ground connection again after the negative electrode connecting resistance R1 of diode D2.
3. high-power LED drive circuit according to claim 2, it is characterized in that described controlled constant-current source circuit comprises operational amplifier U1, operational amplifier U2, power tube Q2, resistance R 12 one end are connected with resistance R 8 with the S utmost point of power tube Q2, other end ground connection; Resistance R 8 is connected with the in-phase input end of operational amplifier U2; Resistance R 7 one end ground connection, the inverting input of other end connecting resistance R5 and operational amplifier U2; The output of resistance R 5 another termination operational amplifier U2, resistance R 10 one end ground connection, the output of another termination operational amplifier U2, realizes LED current sample, and the output of operational amplifier U2 is connected with MCU control unit as the LED current sample port of controlled constant-current source circuit; After the output termination R4 of operational amplifier U2, be connected with the inverting input of operational amplifier U1, MCU control unit brilliance control voltage output connecting resistance R6 after be connected with the in-phase input end of operational amplifier U1 with resistance R 9 respectively, the output of operational amplifier U1 is connected with the G utmost point of power tube Q2, and the S utmost point of power tube Q2 connects LED load.
4. high-power LED drive circuit according to claim 3, characterized by further comprising overvoltage crowbar, described overvoltage crowbar comprises TL431, the negative electrode of described TL431 with after connecting resistance R2, be connected with the negative electrode of diode D2, the plus earth of TL431; The reference utmost point of TL431 is connected with the tie point of resistance R 3 with resistance R 1; Also increased logical AND gate, the negative electrode of described PWM delivery outlet and TL431 is as the input of logical AND gate, and the negative electrode of PWM delivery outlet and TL431 is done to be input to isolation drive after logic and operation again, then is connected with the G utmost point of switching tube Q1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420251828.XU CN203827587U (en) | 2014-05-16 | 2014-05-16 | Large power LED driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420251828.XU CN203827587U (en) | 2014-05-16 | 2014-05-16 | Large power LED driving circuit |
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|---|---|
| CN203827587U true CN203827587U (en) | 2014-09-10 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420251828.XU Expired - Fee Related CN203827587U (en) | 2014-05-16 | 2014-05-16 | Large power LED driving circuit |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109976439A (en) * | 2019-04-29 | 2019-07-05 | 苏州市职业大学 | High efficiency can multi-path flow equalizing constant-current source circuit |
| CN112399673A (en) * | 2020-11-13 | 2021-02-23 | 海宁瑞丰灯头股份有限公司 | High-power LED lamp drive circuit |
-
2014
- 2014-05-16 CN CN201420251828.XU patent/CN203827587U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109976439A (en) * | 2019-04-29 | 2019-07-05 | 苏州市职业大学 | High efficiency can multi-path flow equalizing constant-current source circuit |
| CN112399673A (en) * | 2020-11-13 | 2021-02-23 | 海宁瑞丰灯头股份有限公司 | High-power LED lamp drive circuit |
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| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140910 Termination date: 20160516 |
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| CF01 | Termination of patent right due to non-payment of annual fee |