CN103607110A - Rapid opening switch power supply assisting winding to carry out power supply - Google Patents

Abstract

A rapid opening switch power supply assisting a winding to carry out power supply is disclosed. A PWM control circuit adopts a 5810 chip and is additionally provided with a compensating circuit. The compensating circuit comprises a resistor R9 and a capacitor C6 which are connected in series. A switch sampling circuit comprises a NPMOS pipe Q1, a resistor R2, a resistor R4 and a resistor R8. A drain electrode of the NPMOS pipe Q1 is served as an input terminal of the switch sampling circuit and is connected with a main grade of a transformer. A grid electrode of the Q1 is connected with one end of the resistor R2 and one end of the resistor R4 respectively. The other end of the resistor R2 is connected with a driving port of the 5810 chip. The other end of the resistor R4 is connected with a source electrode of the Q1, one end of a resistor R8 and a current sampling port of the 5810 chip respectively. The other end of the resistor R8 is connected with a ground port of the 5810 chip. An auxiliary charging circuit comprises a resistor R6, a resistor R7, a resistor R10, a diode D3, a diode D4, a diode D5, a capacitor C5 and two auxiliary windings NA1 and NA2 which are located on a same side of the main grade of the transformer.

Description

A kind of quick opening switch power supply of auxiliary winding power supply

Technical field

The present invention relates to Switching Power Supply, relate in particular to a kind of quick opening switch power supply of auxiliary winding power supply, be applicable to LED load.

Background technology

At present, LED lighting technology is rapidly developed, and the LED light fixture on market is more and more, and for different applications, the performance of LED illuminator emphasizes particularly on different fields.For example, minimum without the desk lamp requirement output current ripple of stroboscopic, this obtains with sacrificial system PF value.General room lighting requires to have PFC function, but all LED illuminators are all paid close attention to the opening time of power supply, and this and user's satisfaction is closely bound up.Therefore, how allowing LED illuminator open is fast the problem that each LED designer must consider.In general, the opening time of minimizing LED illuminator should not affect other performances of system.Now some high-end products obtain the very short opening time by some complicated peripheral circuits on the market, but this take and increases cost as cost.

Summary of the invention

The present invention seeks to the defect existing for prior art, a kind of quick opening switch power supply of auxiliary winding power supply is provided, can in the situation that not increasing cost, realizes the quick unlatching of LED system, structure is very simple, do not increase cost, improved the reliability and stability of system simultaneously.

The present invention for achieving the above object, adopt following technical scheme: a kind of quick opening switch power supply of auxiliary winding power supply, basic structure containing inverse-excitation type switch power-supply, comprise input protection circuit, current rectifying and wave filtering circuit, busbar charging circuit, RCD clamp circuit, transformer, output filter circuit, switch sample circuit, pwm control circuit and auxiliary charging circuit, input protection circuit is connected in series current rectifying and wave filtering circuit successively, busbar charging circuit, RCD clamp circuit, transformer and output filter circuit, transformer output sampled signal is to switch sample circuit, switch sample circuit is connected with pwm control circuit is two-way, auxiliary charging circuit and transformer electromagnetic coupled, the output of busbar charging circuit and auxiliary charging circuit is all connected pwm control circuit,

It is characterized in that: pwm control circuit adopts 5810 chips and sets up the compensating circuit for 5810 chips, compensating circuit comprises that resistance R 9 connects with capacitor C 6, the other end of resistance R 9 connects the compensation port COMP of 5810 chips, the other end of capacitor C 6 connects input ground, and the GND port of 5810 chips connects input ground;

Switch sample circuit comprises NMOS pipe Q1, resistance R 2, R4 and R8, the drain electrode of NMOS pipe Q1 is as the Same Name of Ends of the input connection transformer main of switch sample circuit, the grid difference contact resistance R2 of NMOS pipe Q1 and one end of R4, the other end of resistance R 2 connects the driving port DRV of 5810 chips, the other end of resistance R 4 connects respectively the current sample port ISEN of the NMOS pipe source electrode of Q1, one end of resistance R 8 and 5810 chips, and the other end of resistance R 8 connects the GND port of 5810 chips;

Auxiliary charging circuit comprises resistance R 6, R7, R10, diode D3, D4, D5, the auxiliary winding NA1 of capacitor C 5 and two and transformer main homonymy, NA2, the number of turn of the number of turn of auxiliary winding NA2≤auxiliary winding NA1, auxiliary winding NA1, the Same Name of Ends of NA2 connects respectively diode D4, the anode of D5, diode D4, one end of the cathode interconnect of D5 contact resistance R10, the other end of resistance R 10 connects the anode of diode D3 and one end of capacitor C 5, the other end of capacitor C 5 connects input ground, the negative electrode of diode D3 connects the feeder ear VIN of 5810 chips, resistance R 6 is connected with R7, its series connection end connects the zero passage detection end ZCS of 5810 chips, the other end of resistance R 7 connects the anode of diode D4, the other end of resistance R 6 and auxiliary winding NA1, the other end of NA2 connects and connects input ground.

Tool of the present invention has the following advantages and is showing effect:

1), the in the situation that, input voltage range certain at output loading voltage being large, guaranteed the disposable opening of system.

2) circuit is simple, and without the complex control of special circuit, cost is low, good reliability.

3) charging capacitor of legacy system is divided into C4 and C5 two parts, can greatly reduces the charging interval of busbar voltage to control chip, thereby obviously reduce the opening time of Switching Power Supply.

4) two auxiliary winding constructions can have been avoided the secondary opening of Switching Power Supply in Switching Power Supply open stage to charging capacitor quick charge, thereby greatly reduce the opening time of Switching Power Supply.

5) two feeder ear voltages that guaranteed in fact control chip by the connected charging capacitor C4 of diode and C5 is stable, and then has guaranteed high stability and the high reliability of whole switch power supply system work.

Accompanying drawing explanation

Fig. 1 is circuit block diagram of the present invention;

Fig. 2 is circuit theory diagrams of the present invention;

Fig. 3 is the opening time measured waveform figure of power supply model machine of the present invention;

Fig. 4 is the opening time measured waveform figure that does not adopt LED power supply of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the technical scheme of invention is elaborated:

As shown in Figure 1, a kind ofly take inverse-excitation type switch power-supply structure and be that the quick opening switch power supply of the auxiliary winding power supply on basis comprises input protection circuit 1, current rectifying and wave filtering circuit 2, busbar charging circuit 3, RCD clamp circuit 4, transformer 5, output filter circuit 6, switch sample circuit 7, pwm control circuit 8, auxiliary charging circuit 10.Input protection circuit 1 is connected in series current rectifying and wave filtering circuit 2, busbar charging circuit 3, RCD clamp circuit 4, transformer 5 and output filter circuit 6 successively; the elementary output sampled signal of transformer 6 is to switch sample circuit 7; switch sample circuit 7 is connected with pwm control circuit 8 is two-way; auxiliary charging circuit 10 and transformer electromagnetic coupled; the output of busbar charging circuit 3 and auxiliary charging circuit 10 is all connected pwm control circuit 8, and wherein auxiliary charging circuit 10 has adopted an auxiliary winding.The structure of above-mentioned each circuit and annexation thereof are published prior aries.The present invention has given switch sample circuit 7, pwm control circuit 8, auxiliary charging circuit 10 improving as Fig. 2 on the basis of above-mentioned prior art.

In Fig. 2, pwm control circuit 8 adopts 5810 chips and sets up the compensating circuit 9 for 5810 chips, compensating circuit 9 comprises that resistance R 9 connects with capacitor C 6, the other end of resistance R 9 connects the compensation port COMP of 5810 chips, the other end of capacitor C 6 connects input ground, and the GND port of 5810 chips connects input ground.

Switch sample circuit 7 comprises NMOS pipe Q1, resistance R 2, R4 and R8, the drain electrode of NMOS pipe Q1 is as the Same Name of Ends of the input connection transformer main of switch sample circuit, the grid difference contact resistance R2 of NMOS pipe Q1 and one end of R4, the other end of resistance R 2 connects the driving port DRV of 5810 chips, the other end of resistance R 4 connects respectively the current sample port ISEN of the NMOS pipe source electrode of Q1, one end of resistance R 8 and 5810 chips, and the other end of resistance R 8 connects the GND port of 5810 chips.

Auxiliary charging circuit 10 comprises resistance R 6, R7, R10, diode D3, D4, D5, the auxiliary winding NA1 of capacitor C 5 and two and transformer main homonymy, NA2, auxiliary winding NA2 is positioned at primary nearside, the number of turn of the number of turn of auxiliary winding NA2≤auxiliary winding NA1, auxiliary winding NA1, the Same Name of Ends of NA2 connects respectively diode D4, the anode of D5, diode D4, one end of the cathode interconnect of D5 contact resistance R10, the other end of resistance R 10 connects the anode of diode D3 and one end of capacitor C 5, the other end of capacitor C 5 connects input ground, the negative electrode of diode D3 connects the feeder ear VIN of 5810 chips, resistance R 6 is connected with R7, its series connection end connects the zero passage detection end ZCS of 5810 chips, the other end of resistance R 7 connects the anode of diode D4, the other end of resistance R 6 and auxiliary winding NA1, the other end of NA2 connects and connects input ground.

Busbar charging circuit 3 comprises resistance R 3, R5 and capacitor C 4, resistance R 3, R5 connect with capacitor C 4, the other end of resistance R 3 connects respectively the output of current rectifying and wave filtering circuit 2 and the input of RCD clamp circuit, resistance R 5 is connected the feeder ear VIN of 5810 chips with the series connection end of capacitor C 4, another termination input ground of capacitor C 4.

Operation principle of the present invention is as follows:

1) in current rectifying and wave filtering circuit 2, rectifier bridge BD1 becomes the sinusoidal voltage of input into the direct voltage that contains harmonic wave, and capacitor C 1 obtains the less direct voltage of harmonic content after filtering, and this voltage is exactly busbar voltage VBUS.

2) after system power-up, busbar voltage VBUS charges to 5810 chips by resistance R 3, R5 and the capacitor C 4 of busbar charging circuit 3, voltage ramp in capacitor C 4 rises until the threshold value positive voltage of chip, and chip is started working, and the charging interval is t1=1/(R3+R5) * C4.

3) transformer 5 is isolating transformer, plays isolation transformation and the effect of primary and secondary level transferring energy.

4) in switch sample circuit 7, Q1 is switching tube, the feedback signal that resistance R 4, R8 series connection dividing potential drop obtain is delivered to the current sample end ISEN of 5810 chips, control by 5810 chip internals exports Q1 grid to from the drive end (DRV) of 5810 chips, drives and adjust the duty ratio of Q1 grid drive end square wave.

5) 5810 chips are control cores of system, duty ratio, current sample and the overvoltage protection of control switch pipe Q1 gate drive signal.

6) in auxiliary charging circuit 10, the number of turn of auxiliary winding NA1, NA2 is closed and is: the number of turn of the number of turn of auxiliary winding NA2≤auxiliary winding NA1.5810 chips are wanted consumed energy after starting working, lower voltage in capacitor C 4, the energy that transformer 5 mains are stored in magnetic core is simultaneously delivered to secondary and auxiliary winding, auxiliary winding NA1, NA2 are to capacitor C 4, C5 quick charge, voltage in capacitor C 4 is unlikely to be reduced to threshold value negative pressure (voltage in capacitor C 4 lower than threshold value negative pressure time 5810 chips will restart), thereby guaranteed the disposable startup of system, greatly reduced the start-up time of system.

The course of work of the present invention is as follows:

After system powers on, after rectifying and wave-filtering 2, obtain busbar voltage, busbar voltage is through R3, R5 to capacitor C 4 charging, and the voltage ramp on C4 rises until reach the threshold value positive voltage of feeder ear in 5810 chips (VIN), and 5810 chips are started working.Voltage on C4 from the time that is raised to threshold value positive voltage above freezing be t1=1/(R3+R5) * C4, reduce the value of t1, have two kinds of methods: 1. reduce the value of (R3+R5), 2. reduce the value of C4.The value that reduces (R3+R5) reduces the ability of the anti-instant high-voltage of 5810 chip greatly, generally can cause chip to burn.The value that reduces C4 can make C4 maintain the ability reduction of feeder ear in chip (VIN) voltage, but can avoid by auxiliary winding quick charge.

After 5810 chip operations, the grid square wave of switching tube Q1 in drive end (DRV) output driving switch sample circuit 7, the unlatching of switching tube Q1 and shutoff make main quick changes in voltage in transformer 5, and by primary and secondary level power conversion, energy is passed to secondary and auxiliary winding level NA1, NA2.The voltage of auxiliary winding level NA1, NA2 end is greater than feeder ear in chip 5810 (VIN).Diode D3, D4, D5 conducting in auxiliary charging circuit 10, the electric current of auxiliary winding NA1, two branch roads of NA1 to capacitor C 4, C5 quick charge, has maintained voltage stable of feeder ear (VIN) in 5810 chips by R10.

Adopt the present invention, greatly reduced t1, by auxiliary winding NA1, NA2, give fast C4, C5 quick charge again simultaneously, maintained voltage stable of feeder ear (VIN) in 5810 chips.After system normal operation, because C4, C5 (the in good time conducting of D3 meeting) in parallel are equivalent to a large electric capacity, maintain the voltage stabilization of feeder ear (VIN) in rear 5810 chips of system normal operation, improved the stability of system works.

In order to prove circuit performance of the present invention, designed and tested a LED power supply model machine based on structure of the present invention, by test result and the LED power supply test result contrast that does not adopt structure of the present invention.Shown in Fig. 3, be the start-up time that has adopted the system of structure of the present invention, be as can be seen from the figure 336ms start-up time.Shown in Fig. 4, be the start-up time that does not adopt the system of structure of the present invention, be as can be seen from the figure 1.057s start-up time.As can be seen from the above results, after employing the present invention, greatly shorten start-up time, successful.

Circuit of the present invention has adopted the basic structure with inverse-excitation type switch power-supply, also can adopt the Switching Power Supply structure as BUCK circuit.

Claims (1)

1. the quick opening switch power supply of an auxiliary winding power supply, basic structure containing inverse-excitation type switch power-supply, comprise input protection circuit, current rectifying and wave filtering circuit, busbar charging circuit, RCD clamp circuit, transformer, output filter circuit, switch sample circuit, pwm control circuit and auxiliary charging circuit, input protection circuit is connected in series current rectifying and wave filtering circuit successively, busbar charging circuit, RCD clamp circuit, transformer and output filter circuit, transformer output sampled signal is to switch sample circuit, switch sample circuit is connected with pwm control circuit is two-way, auxiliary charging circuit and transformer electromagnetic coupled, the output of busbar charging circuit and auxiliary charging circuit is all connected pwm control circuit,

It is characterized in that: pwm control circuit adopts 5810 chips and sets up the compensating circuit for 5810 chips, compensating circuit comprises that resistance R 9 connects with capacitor C 6, the other end of resistance R 9 connects the compensation port COMP of 5810 chips, the other end of capacitor C 6 connects input ground, and the GND port of 5810 chips connects input ground;

Switch sample circuit comprises NMOS pipe Q1, resistance R 2, R4 and R8, the drain electrode of NMOS pipe Q1 is as the Same Name of Ends of the input connection transformer main of switch sample circuit, the grid difference contact resistance R2 of NMOS pipe Q1 and one end of R4, the other end of resistance R 2 connects the driving port DRV of 5810 chips, the other end of resistance R 4 connects respectively the current sample port ISEN of the NMOS pipe source electrode of Q1, one end of resistance R 8 and 5810 chips, and the other end of resistance R 8 connects the GND port of 5810 chips;

Auxiliary charging circuit comprises resistance R 6, R7, R10, diode D3, D4, D5, the auxiliary winding NA1 of capacitor C 5 and two and transformer main homonymy, NA2, the number of turn of the number of turn of auxiliary winding NA2≤auxiliary winding NA1, auxiliary winding NA1, the Same Name of Ends of NA2 connects respectively diode D4, the anode of D5, diode D4, one end of the cathode interconnect of D5 contact resistance R10, the other end of resistance R 10 connects the anode of diode D3 and one end of capacitor C 5, the other end of capacitor C 5 connects input ground, the negative electrode of diode D3 connects the feeder ear VIN of 5810 chips, resistance R 6 is connected with R7, its series connection end connects the zero passage detection end ZCS of 5810 chips, the other end of resistance R 7 connects the anode of diode D4, the other end of resistance R 6 and auxiliary winding NA1, the other end of NA2 connects and connects input ground.

Images