CN205793525U

CN205793525U - There is the dimming drive power of output no-load protection circuit

Info

Publication number: CN205793525U
Application number: CN201620561770.8U
Authority: CN
Inventors: 杨宗瑞
Original assignee: Zhangshan Kaidij Electronic Co Ltd
Current assignee: Zhangshan Kaidij Electronic Co Ltd
Priority date: 2016-06-08
Filing date: 2016-06-08
Publication date: 2016-12-07
Anticipated expiration: 2026-06-08

Abstract

The utility model discloses the dimming drive power with output no-load protection circuit; including protective tube, rectifier bridge, filter circuit, reduction voltage circuit, PWM adjusting control circuit, drive IC, IC start-up circuit, auxiliary charging circuit, transformator, audion Q1; rectification bridge output end one tunnel is sequentially connected with reduction voltage circuit, PWM adjusting control circuit, the base stage of audion Q1; another road of rectification bridge output end is connected and as load positive input terminal LED+ with driving IC through IC start-up circuit, drives IC outfan to be connected with load negative input end L through transformator main winding.This utility model dimming drive power is by arranging an audion, when load open circuit, drives the output voltage of IC to automatically cut off, after cutting off output, even if load restoration, the most again export, just recovering output until re-powering, such LED would not be injured by current over pulse.

Description

There is the dimming drive power of output no-load protection circuit

Technical field

This utility model relates to LED drive power, particularly has the dimming drive power of output no-load protection circuit.

Background technology

Existing light modulation drives great majority not have output voltage no-load protection function, when load open circuit, owing to driving power supply The character of constant current, can raise output voltage, reaches to export electric current with expectation and returns to the effect of design load, but owing to having loaded Open circuit, so the height of output voltage is essentially close to exchange input rectifying filtered peak value 220*1.141=311V, so If high voltage connects LED load, load can be caused the injury of a current over pulse, LED time serious, will be damaged；Separately There are some to drive power source design, although to be known as and have output voltage no-load protection function, but its protection philosophy is by output voltage Limit within the specific limits, do not cut off exporting when load open circuit, such as the driving power supply of 36W, it exports normally Power is generally 26W-36W, and minimum output voltage is 3V*26=78V, and maximum output voltage is 3.6V*36=130V, so Its open-circuit voltage protection surplus is typically set to add 30V than the highest output, it is simply that 160V, if this scheme load open circuit, output electricity Although pressure will not be raised to 300V, if but the voltage of 160 connects the load of 78V, and the injury of current over pulse cannot be avoided, only Can say it is to reduce injury.

Utility model content

For solving above-mentioned technical problem, the purpose of this utility model is to provide a kind of tune with output no-load protection circuit Optical drive power supply.

The technical solution adopted in the utility model is:

There is the dimming drive power of output no-load protection circuit, including protective tube, rectifier bridge, filter circuit, blood pressure lowering electricity Road, PWM adjusting control circuit, driving IC, IC start-up circuit, auxiliary charging circuit, transformator, audion Q1, described protective tube, Rectifier bridge, filter circuit are sequentially connected with from mains electricity input end, rectification bridge output end one tunnel and reduction voltage circuit, PWM brightness adjustment control electricity Road, the base stage of audion Q1 are sequentially connected with, and another road of rectification bridge output end is connected and as negative with driving IC through IC start-up circuit Carry positive input terminal LED+, drive IC outfan to be connected with load negative input end L-through transformator main winding, transformator auxiliary winding It is connected with the start-up capacitance C4 of IC start-up circuit by auxiliary charging circuit, the emitter stage of audion Q1 and the Enable Pin driving IC DIM1 connects, and the colelctor electrode of audion Q1 is connected with start-up capacitance C4 one end of IC start-up circuit, this start-up capacitance C4 other end And it is serially connected with discharge resistance R26 between the emitter stage of audion Q1.

Described IC start-up circuit also includes two charging resistors R14, R15, and charging resistor R14, that R15 is connected on rectifier bridge is defeated Go out between end and start-up capacitance C4.

Described auxiliary charging circuit is concatenated by resistance R18 and diode D6 and forms.

Described filter circuit is electrochemical capacitor C14.

Between described driving IC outfan and transformator main winding, junction point is by diode and load positive input terminal LED+ Forward connects.

The beneficial effects of the utility model:

This utility model dimming drive power is by arranging an audion, when load open circuit, drives the output electricity of IC Pressure energy automatically cuts off, and after cutting off output, even if load restoration, the most again exports, and just recovers output until re-powering, this Sample LED would not be injured by current over pulse.

Accompanying drawing explanation

Below in conjunction with the accompanying drawings detailed description of the invention of the present utility model is described further.

Fig. 1 is the circuit diagram of this utility model dimming drive power.

Detailed description of the invention

With reference to shown in Fig. 1, for the dimming drive power with output no-load protection circuit of the present utility model, including insurance Pipe, rectifier bridge, filter circuit, reduction voltage circuit, PWM adjusting control circuit, driving IC, IC start-up circuit, auxiliary charging circuit, change Depressor, audion Q1.Wherein, IC start-up circuit includes start-up capacitance C4, two charging resistors R14, R15, charging resistor R14, R15 is connected between rectification bridge output end and start-up capacitance C4, and auxiliary charging circuit is by resistance R18 and diode D6 concatenation Becoming, filter circuit is electrochemical capacitor C14.And reduction voltage circuit, PWM adjusting control circuit are routine techniques in this area, at this not Repeat again.

Described protective tube, rectifier bridge, filter circuit are sequentially connected with from mains electricity input end, rectification bridge output end one tunnel and blood pressure lowering Circuit, PWM adjusting control circuit, the base stage of audion Q1 are sequentially connected with, another road of rectification bridge output end through IC start-up circuit with Drive IC to connect and as load positive input terminal LED+, drive IC outfan through transformator main winding with load negative input end L-even Connecing, transformator auxiliary winding is connected with the start-up capacitance C4 of IC start-up circuit by auxiliary charging circuit, the transmitting of audion Q1 Pole is connected with Enable Pin DIM1 driving IC, and the colelctor electrode of audion Q1 is connected with start-up capacitance C4 one end of IC start-up circuit, It is serially connected with discharge resistance R26 between this start-up capacitance C4 other end and the emitter stage of audion Q1.

Additionally, drive junction point between IC outfan and transformator main winding by diode and to load positive input terminal LED+ Forward connects.

It is below operation principle and the process of the technical program:

Under normal circumstances, AC power supplies is filtered by C14 after F1 protective tube and BD1 rectifier bridge rectification, produces the straight of about 300V Stream voltage, this voltage divides two-way, and a road supplies electricity to PWM light-adjusting module through reduction voltage circuit, and the driving of light modulation is supported in the supply of another road IC circuit 3, is energized the initial stage, PWM module not output level, waits that drive circuit IC3 send pwm signal after reaching startup standard again, IC3 start-up circuit is charged to C4 by R14, R15, reaches startup standard, now pwm signal R9, Q1 when C4 voltage is charged to 14V, IC3 Deliver to the 5th foot of IC3 after audion emitter following carry out output and enable and the adjustment of output electric current, output size of current by PWM duty cycle determines, to reach the purpose of light modulation；

After driving power initiation, the power consumption of IC3 becomes big, and the voltage on C4 is mended through R18, D6 by the auxiliary winding of transformator L1 Filling, when load open circuit, drive the voltage of output to rise therewith, the voltage on C4 also rises, but owing to load has been opened a way, institute Auxiliary winding output current with transformator L1 is less able, so the voltage on C4 can be bled off to R26 by Q1, voltage is put to 6V Time, there is under-voltage protection in IC3, no longer to load output voltage, now L1 also stopped work, and the voltage on C4 can not get Enough guarantors fill, it is impossible to rise to 14V, IC3 and cannot start to recover output, therefore produce self-locking, now, have only driving electricity Road power-off, takes back load, re-powers and can again complete start-up course.

The internal built-in metal-oxide-semiconductor of IC, when metal-oxide-semiconductor conducting, Vth--LED+, L1-, inductance 4,3, to the Drain foot 8,7 of IC, To 6 feet of IC, by RS1,2,3 arrive ground, and metal-oxide-semiconductor turns off, inductance 4, and 3 voltage reversal are discharged to LED by D10, thus reached To the purpose of blood pressure lowering, change RS1,2,3, can regulate output electric current, and the PWM ripple of DIM1 input different duty, Ke Yigai Become the CS threshold voltage of chip internal, thus control peak point current time metal-oxide-semiconductor turns on, thus regulate output electric current, enter one Step light.

The foregoing is only preferred embodiments of the present utility model, this utility model is not limited to above-mentioned embodiment party Formula, if with essentially identical means realize the technical scheme of this utility model purpose broadly fall into protection domain of the present utility model it In.

Claims

1. there is the dimming drive power of output no-load protection circuit, it is characterised in that: include protective tube, rectifier bridge, filtered electrical Road, reduction voltage circuit, PWM adjusting control circuit, driving IC, IC start-up circuit, auxiliary charging circuit, transformator, audion Q1, institute State protective tube, rectifier bridge, filter circuit are sequentially connected with from mains electricity input end, and rectification bridge output end one tunnel is adjusted with reduction voltage circuit, PWM Light control circuit, the base stage of audion Q1 are sequentially connected with, and another road of rectification bridge output end is connected with driving IC through IC start-up circuit And as load positive input terminal LED+, drive IC outfan to be connected with load negative input end L-through transformator main winding, transformator Auxiliary winding is connected with the start-up capacitance C4 of IC start-up circuit by auxiliary charging circuit, the emitter stage of audion Q1 and driving IC Enable Pin DIM1 connect, the colelctor electrode of audion Q1 is connected with start-up capacitance C4 one end of IC start-up circuit, this start-up capacitance Discharge resistance R26 it is serially connected with between the emitter stage of the C4 other end and audion Q1.

The dimming drive power with output no-load protection circuit the most according to claim 1, it is characterised in that: described IC Start-up circuit also includes two charging resistors R14, R15, and charging resistor R14, R15 are connected on rectification bridge output end and start-up capacitance Between C4.

The dimming drive power with output no-load protection circuit the most according to claim 1, it is characterised in that: described auxiliary Charged electrical routing resistance R18 and diode D6 concatenation is helped to form.

The dimming drive power with output no-load protection circuit the most according to claim 1, it is characterised in that: described filter Wave circuit is electrochemical capacitor C14.

The dimming drive power with output no-load protection circuit the most according to claim 1, it is characterised in that drive described in: Move junction point between IC outfan with transformator main winding to be connected with load positive input terminal LED+ forward by diode.