CN105163416A - Improved silicon controlled LED dimming drive circuit - Google Patents

Abstract

The invention relates to an improved silicon controlled LED dimming drive circuit, which comprises a silicon controlled dimming unit. The improved silicon controlled LED dimming drive circuit is characterized in that an output end of the silicon controlled dimming unit is provided with a single-stage PFC conversion unit, a dimming unit, an input voltage waveform detection unit, an output current sampling unit and an output control unit; the output end of the silicon controlled dimming unit is connected to an input end of the single-stage PFC conversion unit, an output end of the single-stage PFC conversion unit is connected to an input end of the output control unit, and the output control unit has a constant-current voltage output end and a power supply input end for external connection with an LED light; and an output end of the output current sampling unit and an output end of the input voltage waveform detection unit are connected with an input end of the dimming unit, and a control signal is outputted through the dimming unit to control the single-stage PFC conversion unit to have a constant output current. The invention has the characteristics of high compatibility, stability and reliability.

Description

A kind of controllable silicon LED dimming driving circuit of improvement

Technical field

The present invention relates to a kind of controllable silicon LED dimming driving circuit of improvement.Belong to LED light modulation driving arrangement (device) technical field.

Background technology

In field of lighting devices, because LED illumination is loved by the people with its energy-conservation and convenient, flexible dimming mode, therefore LED is widely used.Because LED lamp bead is current drive-type, when electric current is non-constant, the useful life of meeting serious curtailment LED lamp bead.

In prior art, the light modulation of LED is typically employed in live wire and is connected in series into controllable silicon dimmer, because these controllable silicon dimmers are by controlling the different phase angle conducting at input voltage sine wave, and the voltage effective value of output is changed, thus reach the object of adjustment LED output current.Although which realizes LED light modulation, but there is following shortcoming: 1, due to controllable silicon must be minimum maintenance electric current could normally, so during zero passage, easily can cause silicon controlled switch bounce, the instability of LED output current can be caused, and cause the scintillation of light; 2, silicon controlled cut mode can cause the harmonic distortion of circuit relatively more serious, has a strong impact on the normal power supply of electrical network; 3, due to the technical parameter inconsistency of controllable silicon dimmer on the market, the dimming technique parameter that each producer does is all inconsistent, so the compatibility issue causing dimmer to drive with LED is more outstanding, when this dimmer of cooperation is fine, but changing a dimmer just there is the problem that LED glimmers.

Therefore, design a kind of controllable silicon LED dimming driving circuit of improvement, to solve the problem of present controllable silicon dimmer job insecurity, poor compatibility, the development of LED industry is had great significance.The present invention is the drive circuit of a kind of constant current controlling LED luminescence work,

Summary of the invention

Object of the present invention, being the poor compatibility that controllable silicon dimmer in order to overcome prior art and LED drive and the problem easily causing LED to glimmer, providing a kind of LED thyristor regulating light drive circuit of improvement.The present invention, when silicon control zero-cross, maintains silicon controlled minimal maintenance electric current, and allows controllable silicon under minimum current state, also keep conducting state, realize LED steady operation, have compatible strong, reliable and stable feature.

Object of the present invention can be reached by following measure:

A kind of LED thyristor regulating light drive circuit of improvement, comprise controllable silicon light modulation unit, its design feature is: arrange single-stage PFC converting unit, dimming unit, input voltage waveform detecting unit, output current sampling unit and output control unit at the output of controllable silicon light modulation unit; The input of controllable silicon light modulation unit connects civil power, output connects the input of single-stage PFC converting unit and the input of input voltage waveform detecting unit, the output of single-stage PFC converting unit connects the input of output control unit, and output control unit has constant current voltage output end, power input for external LED; The input of output current sampling unit connects one of the output of single-stage PFC converting unit, input of output connection dimming unit, the input of input voltage waveform detecting unit connects the input of single-stage PFC converting unit, the input two of output connection dimming unit, the output of dimming unit connects the feedback input end of single-stage PFC converting unit, forms the feedback loop of single-stage PFC converting unit; By input voltage waveform detecting unit and output current sampling unit, the output current to the output voltage of dimming unit and single-stage PFC converting unit carries out sample detecting, and export by dimming unit the constant output current that control signal controls single-stage PFC converting unit, form the drive circuit of constant current controlling LED luminescence work.

Object of the present invention can also be reached by following measure:

Further, single-stage PFC converting unit comprises EMI filter circuit, commutating circuit BD2, energy transmission and electrical isolation loop, control loop and coupling output loop; The output of the input connection controllable silicon light modulation unit of EMI filter circuit, output pass through the voltage input end of commutating circuit BD2 butt coupling output loop, control loop is formed by connecting primarily of the resistance of control chip IC3, field effect transistor Q11 and optocoupler ICB and periphery thereof, electric capacity, diode, control chip IC3 has pulse signal input terminal with the control input end of the output of external control impuls input signal PWM, control chip IC3 by field effect transistor Q11 butt coupling output loop; Coupling output loop comprises coupling transformer T2A and just organizes winding T2B-T2C, described armature winding T2B and rectifier diode D13, electrolysis EC6 and resistance R58-R57 form the current supply circuit of IC3, and described armature winding T2B connects the input of input voltage waveform detecting unit by triode Q5, optocoupler ICB; Described just group winding T2C connects the power input of dimming unit, thinks that dimming unit provides power supply; The feedback signal input terminal MULT of control chip IC3 connects the signal output part of dimming unit.

Further, dimming unit is primarily of field effect transistor Q16 and Q18, triode Q12, the resistance of Q14 and Q17 and periphery, electric capacity, diode, voltage stabilizing didoe is formed by connecting, the base stage of Q14 base stage connects the signal output part of input voltage waveform detecting unit, form one of dimming unit feedback input end, the emitter of triode Q12 connects the output of output current sampling unit, form dimming unit feedback input end two, Q14 collector electrode connects the grid of field effect transistor Q16 and passes through resistance R62, R67, R69 connects the feedback signal input terminal MULT that single-stage PFC converting unit forms dimming unit, form the output of dimming unit, the grid of field effect transistor Q18 connects voltage end SVCC1 by resistance R9.

Further, input voltage waveform detecting unit is formed by connecting primarily of triode Q13 and Q15, diode D6 and D11, resistance R59-R60, R78-R79 and voltage stabilizing didoe ZD9-ZD10; The base stage of Q15 connects first group of winding T2B of single-stage PFC converting unit by diode ZD9, resistance R79, diode D11, form input voltage waveform detecting unit and survey input, the emitter of Q15 forms the output of input voltage waveform detecting unit, connect one end of resistance R70 and C16 parallel combination in dimming unit, described resistance R70 is connected the feedback signal input terminal MULT that single-stage PFC converting unit forms dimming unit with the other end of C16 parallel combination.

Further, current sampling unit is formed by connecting primarily of the resistance of voltage follow chip IC 5 and periphery thereof, electric capacity, the power input VOC of voltage follow chip IC 5 connects the voltage end SVCC of output control unit, the signal input part out of voltage follow chip IC 5 connects the control output end A of output control unit, and the output Vta of voltage follow chip IC 5 connects the collector electrode of the Q17 of dimming unit, forms the output of current sampling unit.

Further, output control unit is formed by connecting primarily of resistance R30-R31 and R71, voltage stabilizing didoe ZD8 and light-emitting diode IC4A; One termination SVCC, the other end of resistance R30 are connected with the positive pole of light-emitting diode IC4A by resistance R31, the negative pole of light-emitting diode IC4A is connected to the signal input part out of voltage follow chip IC 5 in current sampling unit by resistance R71, the positive pole of the negative electrode connecting luminous diode IC4A of the plus earth GND of voltage stabilizing didoe ZD8, voltage stabilizing didoe ZD8.

The present invention has following outstanding beneficial effect:

1, the present invention is by arranging input voltage waveform detecting unit and output current sampling unit, the input of output current sampling unit connects one of the output of single-stage PFC converting unit, input of output connection dimming unit, the input of input voltage waveform detecting unit connects the input of single-stage PFC converting unit, the input two of output connection dimming unit, the output of dimming unit connects the feedback input end of single-stage PFC converting unit, forms the feedback loop of single-stage PFC converting unit; By input voltage waveform detecting unit and output current sampling unit, the output current to the output voltage of dimming unit and single-stage PFC converting unit carries out sample detecting, and export by dimming unit the constant output current that control signal controls single-stage PFC converting unit, form the drive circuit of constant current controlling LED luminescence work; Therefore, when silicon control zero-cross, maintain silicon controlled minimal maintenance electric current, and allow controllable silicon under minimum current state, also keep conducting state, realize LED steady operation, there is compatible strong, reliable and stable feature.

2, the present invention formed between the transformer secondary coil and LED of single-stage PFC converting unit LED power protective circuit with filtering circuit ripple and prevent overvoltage, overcurrent damages LED; solve present controllable silicon single-stage light adjusting circuit and there is ripple output greatly; there is stroboscopic phenomenon in LED, ensure that stability and the reliability of LED work.Have structure simple, without the beneficial effect of stroboscopic and duplicate protection.

3, the output voltage signal of the secondary coil of the transformer of single-stage PFC converting unit of the present invention is by electric capacity C2 by prime C3 two ends output voltage filtering rear drive field effect transistor Q1, and Q1 is operated in variable resistor district.By the bias voltage that bias generator circuit produces, control the operating state of metal-oxide-semiconductor Q1, make the ER effect of LED obtain smoothly, substantially improve the shimmering of under degree of depth light modulation LED, realize the object without stroboscopic, health environment-friendly.

3, in specific embodiment of the invention scheme, in start-up course, electric current is by diode D2 and voltage-stabiliser tube ZD1, and electrochemical capacitor C2 is full of very soon, and Q1 is open-minded for driven MOS pipe, and electric current is also lighted rapidly by LED; After the voltage rise of electrochemical capacitor C2 is stable, electrochemical capacitor C2 connects R1, R2 as filter, effectively can reduce the high frequency switching ripple that in start-up course, spread of voltage produces, thus eliminates LED stroboscopic.

Accompanying drawing explanation

Fig. 1 is the circuit block diagram of the specific embodiment of the invention 1.

Fig. 2 is the circuit theory diagrams of the specific embodiment of the invention 1.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in further detail:

Specific embodiment:

With reference to Fig. 1, the present embodiment comprises controllable silicon light modulation unit 1, arranges single-stage PFC converting unit 2, dimming unit 3, input voltage waveform detecting unit 4, output current sampling unit 5 and output control unit 6 at the output of controllable silicon light modulation unit; The input of controllable silicon light modulation unit 1 connects civil power, output connects the input of single-stage PFC converting unit 2 and the input of input voltage waveform detecting unit, the output of single-stage PFC converting unit 2 connects the input of output control unit 6, and output control unit 6 has constant current voltage output end, power input for external LED; The input of output current sampling unit 5 connects one of the output of single-stage PFC converting unit 2, input of output connection dimming unit 3, the input of input voltage waveform detecting unit 4 connects the input of single-stage PFC converting unit 2, the input two of output connection dimming unit 3, the output of dimming unit 3 connects the feedback input end of single-stage PFC converting unit 2, forms the feedback loop of single-stage PFC converting unit 2; By input voltage waveform detecting unit 4 and output current sampling unit, the output current to the output voltage of dimming unit 1 and single-stage PFC converting unit 2 carries out sample detecting, and export by dimming unit 3 constant output current that control signal controls single-stage PFC converting unit, form the drive circuit of constant current controlling LED luminescence work.

With reference to Fig. 2, in the present embodiment:

Single-stage PFC converting unit 2 comprises EMI filter circuit, commutating circuit BD2, energy transmission and electrical isolation loop, control loop and coupling output loop; The output of the input connection controllable silicon light modulation unit 1 of EMI filter circuit, output pass through the voltage input end of commutating circuit BD2 butt coupling output loop, control loop is formed by connecting primarily of the resistance of control chip IC3, field effect transistor Q11 and optocoupler ICB and periphery thereof, electric capacity, diode, control chip IC3 has pulse signal input terminal with the control input end of the output of external control impuls input signal PWM, control chip IC3 by field effect transistor Q11 butt coupling output loop; Coupling output loop comprises coupling transformer T2A and just organizes winding T2B-T2C, described armature winding T2B and rectifier diode D13, electrolysis EC6 and resistance R58-R57 form the current supply circuit of IC3, and described armature winding T2B connects the input of input voltage waveform detecting unit 4 by triode Q5, optocoupler ICB; Described just group winding T2C connects the power input of dimming unit 3, thinks that dimming unit 3 provides power supply; The feedback signal input terminal MULT of control chip IC3 connects the signal output part of dimming unit 3.

Dimming unit 3 is primarily of field effect transistor Q16 and Q18, triode Q12, the resistance of Q14 and Q17 and periphery, electric capacity, diode, voltage stabilizing didoe is formed by connecting, the base stage of Q14 base stage connects the signal output part of input voltage waveform detecting unit 4, form one of dimming unit 3 feedback input end, the emitter of triode Q12 connects the output of output current sampling unit 5, form dimming unit 3 feedback input end two, Q14 collector electrode connects the grid of field effect transistor Q16 and passes through resistance R62, R67, R69 connects the feedback signal input terminal MULT that single-stage PFC converting unit 2 forms dimming unit 3, form the output of dimming unit 3, the grid of field effect transistor Q18 connects voltage end SVCC1 by resistance R9.

Input voltage waveform detecting unit 4 is formed by connecting primarily of triode Q13 and Q15, diode D6 and D11, resistance R59-R60, R78-R79 and voltage stabilizing didoe ZD9-ZD10; The base stage of Q15 connects first group of winding T2B of single-stage PFC converting unit 2 by diode ZD9, resistance R79, diode D11, form input voltage waveform detecting unit 4 and detect input, the emitter of Q15 forms the output of input voltage waveform detecting unit 4, connect one end of resistance R70 and C16 parallel combination in dimming unit 3, described resistance R70 is connected the feedback signal input terminal MULT that single-stage PFC converting unit 2 forms dimming unit 3 with the other end of C16 parallel combination.

Current sampling unit 5 is formed by connecting primarily of the resistance of voltage follow chip IC 5 and periphery thereof, electric capacity, the power input VOC of voltage follow chip IC 5 connects the voltage end SVCC of output control unit 6, the signal input part out of voltage follow chip IC 5 connects the control output end A of output control unit 6, and the output Vta of voltage follow chip IC 5 connects the collector electrode of the Q17 of dimming unit 3, forms the output of current sampling unit 5.

Output control unit 6 is formed by connecting primarily of resistance R30-R31 and R71, voltage stabilizing didoe ZD8 and light-emitting diode IC4A; One termination SVCC, the other end of resistance R30 are connected with the positive pole of light-emitting diode IC4A by resistance R31, the negative pole of light-emitting diode IC4A is connected to the signal input part out of voltage follow chip IC 5 in current sampling unit 5 by resistance R71, the positive pole of the negative electrode connecting luminous diode IC4A of the plus earth GND of voltage stabilizing didoe ZD8, voltage stabilizing didoe ZD8.

The more detailed circuit connecting relation of the present embodiment is as follows:

One end of L8 is connected with one end of electric capacity CX1, resistance R1, inductance L 5; The other end of L8 is connected with one end of the other end of electric capacity CX1, resistance R5, inductance L 6; The other end of inductance L 5 connects one end of adjustable resistor VT2 and the output of dimmer circuit, and the other end of inductance L F6 is connected with the other end of adjustable resistor VT2 and is connected to the zero line of civil power; The other end of the primary coil of L8 is connected to an input of the rectifier bridge connected and composed by diode D1 ~ D4 by inductance L 7, the other end of the secondary coil of L8 is connected to another input of described rectifier bridge; One end of the negative electrode of the positive output end of rectifier bridge and the anode of voltage stabilizing didoe TV2, TV3, electric capacity C1, C3, transformer T2A primary coil is connected; The negative output terminal of rectifier bridge is connected with the other end of the negative electrode of voltage stabilizing didoe TV2, electric capacity C1 and receives common port; The other end of transformer T2A primary coil is connected with the other end of the drain electrode of the positive pole of diode D2, electric capacity C3, metal-oxide-semiconductor Q11; The negative electrode of voltage stabilizing didoe TV3 connects the negative pole of diode D2; One pin of chip IC 3 is connected with one end of resistance R66, R68, electric capacity C14, and the other end of resistance R66 is connected with an output of one end of resistance R65, optocoupler ICB; Another termination common port of resistance R65; Another output of optocoupler ICB is connected with 8 pin of resistance R19, chip IC 3 and meets VCC1, and the other end of resistance R19 connects the positive output end of rectifier bridge, 2 pin of another termination chip IC 3 of electric capacity C14 and resistance R68 by resistance R18; 3 pin of chip IC 3 connect one end of resistance R69, R70 of light adjusting circuit; 4 pin of chip IC 3 are connected with the source electrode of resistance R28, R29, metal-oxide-semiconductor Q11, another termination common port of resistance R29; The grid of metal-oxide-semiconductor Q11 is connected with the other end of one end of resistance R26, resistance R28,7 pin of another termination chip IC 3 of resistance R26, one end of 5 pin contact resistance R17 of chip IC 3, and 6 pin of chip IC 3 connect common port; One end of the secondary coil of transformer T2A is connected with one end of the positive pole of diode D5, electric capacity C5, and the other end of resistance C5 is connected with the negative pole of electrochemical capacitor EC2, diode D5, one end of inductance L 9 by resistance R5; The other end of resistance L9 is connected with the positive pole of the positive terminal of LED, electrochemical capacitor EC3, the negative pole of voltage stabilizing didoe ZD2, the other end of the secondary coil of transformer T2A, electrochemical capacitor EC2 ground connection GND; The positive pole of voltage stabilizing didoe ZD2, the negative pole end of LED and electrochemical capacitor EC3 are connected to ground GND by resistance R11.

One end of armature winding T2B is connected with the positive pole of resistance R17, diode D13, and one end of the negative pole of diode D13, the positive pole of electrochemical capacitor EC6, resistance R58, R77 is connected with the collector electrode of triode Q5; The anode of the other end of inductance T2B, electrochemical capacitor EC6, electric capacity C6 and voltage stabilizing didoe ZD3 is connected to common port; The emitter of the other end of resistance R77 and the base stage of triode Q5, triode Q13, one end of resistance R78, the negative electrode of voltage-stabiliser tube ZD3, the negative pole of diode D5 are connected; The other end of the emitter of triode Q5 and another termination VCC1 of electric capacity C6, resistance R58 is connected to the positive output end of the rectifier bridge of single-stage PFC change-over circuit 1 by resistance R57; The base stage of triode Q13 is connected with the other end of the collector electrode of triode Q15, resistance R78; The collector electrode of triode Q13 is connected with the anode of the base stage of triode Q15, voltage stabilizing didoe ZD9, and the negative electrode of voltage stabilizing didoe ZD9 connects the negative pole of diode D1 by resistance R79, the positive pole of diode D1 meets VCC, and the emitter of triode Q15 connects common port.

The one termination SVCC of resistance R30, the other end is connected with the negative electrode of voltage stabilizing didoe ZD8, the positive pole of light-emitting diode IC4A by resistance R31, the negative pole of light-emitting diode IC4A is connected to one end of resistance R41, R42 of output current sample circuit 4, the plus earth GND of voltage stabilizing didoe ZD8 by resistance R71.

One end of resistance R12 connects the negative pole of diode D5, and the other end is connected with one end of resistance R15, R38, electric capacity C9,7 pin of chip IC 5; The other end of resistance R15 is connected to the positive pole of LED by electric capacity CY4; The other end of electric capacity C9 is connected with 6 pin of chip IC 5, one end of resistance R42 by resistance R41; The other end of resistance R42 is connected with 3 pin of resistance R76, R81 one end, chip IC 5 by electric capacity C13; The other end of resistance R76 connects the negative pole of LED; Be connected 5 pin of chip IC 5 after one end docking of resistance R51 with R75, the other end of resistance R75 is connected to 1 pin of chip IC 5, the other end of resistance R51 and 4 pin ground connection GND of chip IC 5; 2 pin of chip IC 5 are connected with one end of resistance R73, R74, and the other end of resistance R74 is connected SVCC with 8 pin of chip IC 5.

The base stage of triode Q14 is connected with the negative electrode of one end of resistance R61, voltage stabilizing didoe ZD10, and the anode of voltage stabilizing didoe ZD10 is connected to HV by resistance R59, R60; The collector electrode of triode Q14 is connected with the negative electrode of resistance R62, voltage stabilizing didoe ZD7, the grid of metal-oxide-semiconductor Q16; The emitter of triode Q14 is connected with the negative electrode of the other end of resistance R61, voltage stabilizing didoe ZD7 and receives common port; The source electrode of triode Q16 is connected with resistance R63, diode D8 positive pole, and the negative pole of diode D8 meets VCC1; The other end of resistance R63 is connected to common port by resistance R64; One end of the drain electrode of triode Q16, the other end of resistance R62 and resistance R67 is connected to HV; The other end of resistance R67 is connected by one end of 3 pin of resistance R69 and chip IC 3, resistance R70, electric capacity C16, another termination common port of resistance R70 and electric capacity C16; The base stage of triode Q12 is connected with the positive pole of one end of resistance R33, R34, diode D7, the negative electrode of voltage stabilizing didoe ZD6, is connected to the positive pole of LED after the emitter of triode Q12 is connected with the negative pole of diode D7 by resistance R37; The other end of resistance R34, the negative pole of electrochemical capacitor EC8 and diode D15 meet SVCC, the positive pole of diode D15 is connected with the positive pole of one end of inductance T2C, diode D4, the negative pole of diode D4 is connected with one end of electric capacity CY5 and meets SVCC1, the other end ground GND of electric capacity CY5; The other end ground connection GND of the collector electrode of triode Q12, the negative pole of electrochemical capacitor EC8, resistance R33 and inductance T2C; The base stage of triode Q17 is connected with the drain electrode of resistance R80, metal-oxide-semiconductor Q18, one end of resistance R72, and the other end of resistance R72 is connected with one end of electric capacity C17, C20, the other end ground connection GND of electric capacity C17 and C20, another termination SVCC of resistance R32; The grid of metal-oxide-semiconductor Q18 is connected with one end of resistance R9, R40, and the source electrode of metal-oxide-semiconductor Q18 is connected with the other end of resistance R40, R80 and draws ground GND; The collector electrode of triode Q17 connects 1 pin of IC5.Electric capacity CY6 is serially connected with between described common port and ground GND.

The operation principle of the present embodiment:

As shown in Figure 1, after access civil power, electric current is through L5, the electromagnetic interface filters such as L6, L8, L7 carry out filtering, then carry out rectification through rectifier bridge BD2, then enter and carry out by IC3 the single-stage PFC inverse-excitation type control circuit that controls, transformer T2 carries out energy transmission and electrical isolation effect.Control IC3 controls driving pulse driven MOS pipe Q11 by PWM and carries out switch, thus carries out copped wave to input rectifying voltage, then by the coupling of transformer, the energy transferring of input to output, exports termination LED lamp, thus LED lamp is lighted.In primary side, the auxiliary winding T2B of transformer, rectifier diode D13, filtering electrolysis EC6, R58, R57 forms the supply line of IC3, R77, voltage-stabiliser tube ZD3, triode Q5 forms the voltage stabilizing circuit to input supply power voltage, R18, R19, R59, R60 gathers controllable silicon input voltage waveform signal, and follow the tracks of the change of its waveform, when loss thyristor zero-voltage, Q14 triode can be closed, metal-oxide-semiconductor Q16 can be opened, busbar voltage after rectification can compensate to IC3, thus the normal work of IC3 can be maintained, thus maintain silicon controlled minimal maintenance electric current, and allow controllable silicon also keep conducting state under minimum current state.With the while of drawing, at secondary end, R11 gathers the electric current of LED, when silicon controlled rectifier regulation phase place is maximum, namely when the effective value after rectification is minimum, the voltage of SVCC end can followed by reduction, LED output current also can and then reduce, Q12 triode is opened simultaneously, to need large power output, to maintain silicon controlled normally, simultaneously due to the minimizing of input voltage, in order to maintain normal output, the pulsewidth of metal-oxide-semiconductor Q11 can broaden, so the voltage of SVCC1 becomes large on the contrary, so the base voltage of Q17 triode can reduce, the 3rd pin current potential of IC5 can follow minimizing, therefore the electric current of LED can keep, but due to input voltage also continue down to reduce time, the electric current of LED also can reduce state by synchronism stability, and there will not be bounce status.Therefore the object of the perfect light modulation of silicon controlled is achieved.

The above; be only the present invention's preferably specific embodiment; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the scope that the present invention discloses; be equal to according to technical scheme of the present invention and inventive concept thereof and replace or change, all belonged to protection scope of the present invention.

Claims (6)

1. the LED thyristor regulating light drive circuit improved, comprise controllable silicon light modulation unit (1), it is characterized in that: single-stage PFC converting unit (2), dimming unit (3), input voltage waveform detecting unit (4), output current sampling unit (5) and output control unit (6) are set at the output of controllable silicon light modulation unit; The input of controllable silicon light modulation unit (1) connects civil power, output connects the input of single-stage PFC converting unit (2) and the input of input voltage waveform detecting unit, the output of single-stage PFC converting unit (2) connects the input of output control unit (6), and output control unit (6) has constant current voltage output end, power input for external LED; The input of output current sampling unit (5) connects one of the output of single-stage PFC converting unit (2), input of output connection dimming unit (3), the input of input voltage waveform detecting unit (4) connects the input of single-stage PFC converting unit (2), the input two of output connection dimming unit (3), the output of dimming unit (3) connects the feedback input end of single-stage PFC converting unit (2), forms the feedback loop of single-stage PFC converting unit (2); By input voltage waveform detecting unit (4) and output current sampling unit, the output current to the output voltage of dimming unit (1) and single-stage PFC converting unit (2) carries out sample detecting, and export by dimming unit (3) constant output current that control signal controls single-stage PFC converting unit (2), form the drive circuit of constant current controlling LED luminescence work.

2. the LED thyristor regulating light drive circuit of a kind of improvement according to claim 1, is characterized in that: single-stage PFC converting unit (2) comprises EMI filter circuit, commutating circuit BD2, energy transmission and electrical isolation loop, control loop and coupling output loop; The output of input connection controllable silicon light modulation unit (1) of EMI filter circuit, output pass through the voltage input end of commutating circuit BD2 butt coupling output loop, control loop is formed by connecting primarily of the resistance of control chip IC3, field effect transistor Q11 and optocoupler ICB and periphery thereof, electric capacity, diode, control chip IC3 has pulse signal input terminal with the control input end of the output of external control impuls input signal PWM, control chip IC3 by field effect transistor Q11 butt coupling output loop; Coupling output loop comprises coupling transformer T2A and just organizes winding T2B-T2C, described armature winding T2B and rectifier diode D13, electrolysis EC6 and resistance R58-R57 form the current supply circuit of IC3, and described armature winding T2B connects the input of input voltage waveform detecting unit (4) by triode Q5, optocoupler ICB; Described just group winding T2C connects the power input of dimming unit (3), thinks that dimming unit (3) provides power supply; The feedback signal input terminal MULT of control chip IC3 connects the signal output part of dimming unit (3).

3. the LED thyristor regulating light drive circuit of a kind of improvement according to claim 1 and 2, it is characterized in that: dimming unit (3) is primarily of field effect transistor Q16 and Q18, triode Q12, the resistance of Q14 and Q17 and periphery, electric capacity, diode, voltage stabilizing didoe is formed by connecting, the base stage of Q14 base stage connects the signal output part of input voltage waveform detecting unit (4), form one of dimming unit (3) feedback input end, the emitter of triode Q12 connects the output of output current sampling unit (5), form dimming unit (3) feedback input end two, Q14 collector electrode connects the grid of field effect transistor Q16 and passes through resistance R62, R67, R69 connects the feedback signal input terminal MULT that single-stage PFC converting unit (2) forms dimming unit (3), form the output of dimming unit (3), the grid of field effect transistor Q18 connects voltage end SVCC1 by resistance R9.

4. the LED thyristor regulating light drive circuit of a kind of improvement according to claim 1 and 2, is characterized in that: input voltage waveform detecting unit (4) is formed by connecting primarily of triode Q13 and Q15, diode D6 and D11, resistance R59-R60, R78-R79 and voltage stabilizing didoe ZD9-ZD10; The base stage of Q15 connects first group of winding T2B of single-stage PFC converting unit (2) by diode ZD9, resistance R79, diode D11, form input voltage waveform detecting unit (4) and detect input, the emitter of Q15 forms the output of input voltage waveform detecting unit (4), connect one end of resistance R70 and C16 parallel combination in dimming unit (3), described resistance R70 is connected the feedback signal input terminal MULT that single-stage PFC converting unit (2) forms dimming unit (3) with the other end of C16 parallel combination.

5. the LED thyristor regulating light drive circuit of a kind of improvement according to claim 1 and 2, it is characterized in that: current sampling unit (5) is primarily of the resistance of voltage follow chip IC 5 and periphery thereof, electric capacity is formed by connecting, the power input VOC of voltage follow chip IC 5 connects the voltage end SVCC of output control unit (6), the signal input part out of voltage follow chip IC 5 connects the control output end A of output control unit (6), the output Vta of voltage follow chip IC 5 connects the collector electrode of the Q17 of dimming unit (3), form the output of current sampling unit (5).

6. the LED thyristor regulating light drive circuit of a kind of improvement according to claim 1 and 2, is characterized in that: output control unit (6) is formed by connecting primarily of resistance R30-R31 and R71, voltage stabilizing didoe ZD8 and light-emitting diode IC4A; One termination SVCC, the other end of resistance R30 are connected with the positive pole of light-emitting diode IC4A by resistance R31, the negative pole of light-emitting diode IC4A is connected to the signal input part out of voltage follow chip IC 5 in current sampling unit (5) by resistance R71, the positive pole of the negative electrode connecting luminous diode IC4A of the plus earth GND of voltage stabilizing didoe ZD8, voltage stabilizing didoe ZD8.