CN202503732U

CN202503732U - Liner non-isolated light-emitting diode (LED) driving power supply with high power factors

Info

Publication number: CN202503732U
Application number: CN2012200898069U
Authority: CN
Inventors: 李大钦; 李静怡; 徐华贵
Original assignee: HEFEI YINGTE ELECTRIC EQUIPMENTS CO Ltd
Current assignee: HEFEI YINGTE ELECTRIC EQUIPMENTS CO Ltd
Priority date: 2012-03-10
Filing date: 2012-03-10
Publication date: 2012-10-24
Anticipated expiration: 2022-03-10

Abstract

The utility model discloses a liner non-isolated light-emitting diode (LED) driving power supply with high power factors. An alternative current input line is used for supplying power to an LED load through a diode rectifier bridge DB1, a valley-filled power factor correction (PFC) circuit and a constant current control circuit orderly; and the constant current control circuit is also connected to a feedback circuit. The liner non-isolated light-emitting diode (LED) driving power supply with high power factors disclosed by the utility model uses valley-filled power factor correction, can achieve a higher power factor by matching with a chip of type LNK306 and has the advantages of small volume, low cost and high efficiency.

Description

The LED driving power with High Power Factor of the non-isolation of a kind of linearity

Technical field

The utility model relates to the LED field, is specially the LED driving power with High Power Factor of the non-isolation of a kind of linearity.

Background technology

LED is because numerous advantages such as environmental protection, life-span length, photoelectric efficiency height, the application in every profession and trade in recent years more and more widely, this wherein the driving power of LED become the focus of attention.The useful life of LED is more than 100,000 hours in theory, but in actual application, because that the design of driving power and type of drive are selected is improper, LED very easily damaged.Prior art LED driving power commonly used is the constant-current driving formula.According to electric current, the change in voltage rule of LED, generally using forward voltage is about 3.0-3.6V, and representative value voltage is 3.3V; Electric current is 20mA (3528 light sources is example), after the forward voltage that is added on the LED two ends surpasses 3.6V, as long as forward voltage has increase by a small margin; The forward current of LED all has at double and rises, and makes the temperature rise of LED luminous element too fast, thereby quickens the LED optical attenuation; Make the lost of life of LED, when serious even can burn out LED.According to voltage, electric current variation characteristic, LED proposes to be strict with to the design of driving power, be necessary for constant-current driving, but traditional constant current design cost is too high, and power factor is lower, is unfavorable for the universal use of LED.

The utility model content

The utility model purpose provides the LED driving power with High Power Factor of the non-isolation of a kind of linearity, to solve the lower problem of prior art constant-current driving formula LED driving power power factor.

In order to achieve the above object, the technical scheme that the utility model adopted is:

The LED driving power with High Power Factor of the non-isolation of a kind of linearity; Include the alternating current incoming line; It is characterized in that: also comprise diode rectifier bridge DB1, valley fill type pfc circuit, be the constant-current control circuit that the loop of chip U1 and the chip U1 control of LNK306 constitutes by model; Said alternating current incoming line inserts diode rectifier bridge DB1 input, and the output of diode rectifier bridge DB1 inserts the valley fill type pfc circuit, and the output of said valley fill type pfc circuit inserts constant-current control circuit; The loop output line inserts the external LED load in the said constant-current control circuit, between loop output line and chip U1, also has access to feedback circuit.

The LED driving power with High Power Factor of the non-isolation of described a kind of linearity; It is characterized in that: said valley fill type pfc circuit is by three diode in series D3, D1, D2 successively in the same way, and be connected the electrochemical capacitor C1 between diode D1 anode and the diode D2 negative electrode, the electrochemical capacitor C2 that is connected between diode D3 anode and the diode D1 negative electrode constitutes.

The LED driving power with High Power Factor of the non-isolation of described a kind of linearity; It is characterized in that: in the said constant-current control circuit; Loop is connected and composed by inductance L 1, sustained diode 4, the sealing of electrochemical capacitor C4 loop; Wherein sustained diode 4 anodes connect inductance L 1; Sustained diode 4 negative electrodes meet electrochemical capacitor C4; Draw the D pin of lead through chip U1 in the loop between inductance L 1, sustained diode 4 anodes and insert the built-in switch mosfet of chip U1, in the loop between sustained diode 4 negative electrodes and the electrochemical capacitor C4, lead to the loop output line respectively, the load of loop output line access external LED between inductance L 1 and the electrochemical capacitor C4.

The LED driving power with High Power Factor of the non-isolation of described a kind of linearity; It is characterized in that: said feedback circuit comprises the parallel circuits that sampling resistor R1 parallel with one another, R3 constitute; And optocoupler OP1; Said parallel circuits is connected on one of them loop output line and inserts between the input pin of optocoupler OP1, and output pin of optocoupler OP1 inserts the FB pin of chip U1, and another output pin of optocoupler OP1 inserts on the BP pin of chip U1.

The LED driving power with High Power Factor of the non-isolation of described a kind of linearity is characterized in that: have access to fuse F1 on the said alternating current incoming line.

The utility model adopts the calibration of valley fill type power factor, with model be that the chip of LNK306 is used, can reach higher power factor, it is little to have a volume, cost is low, the efficient advantages of higher.

Description of drawings

Fig. 1 is the circuit theory diagrams of the utility model.

Embodiment

As shown in Figure 1.The LED driving power with High Power Factor of the non-isolation of a kind of linearity; Include the alternating current incoming line; Also comprise diode rectifier bridge DB1, valley fill type pfc circuit, be the constant-current control circuit that the loop of chip U1 and the chip U1 control of LNK306 constitutes by model; The alternating current incoming line inserts diode rectifier bridge DB1 input, and the output of diode rectifier bridge DB1 inserts the valley fill type pfc circuit, and the output of valley fill type pfc circuit inserts constant-current control circuit; The loop output line inserts the external LED load in the constant-current control circuit, between loop output line and chip U1, also has access to feedback circuit.

It is the chip U1 of LNK306 that the utility model adopts model; Chip U1 has the pulse generator of the cyclic pulse signal of predetermined ON time and turn-off time, by the switch of pulse generator control, thereby during ON time, opens so that output current is controlled; The power supply that output is predetermined. and have perfect safeguard measure; Comprise: output overcurrent restriction, overtemperature protection, short-circuit protection, make power work safe and reliable, not fragile.

Insert the fuse F1 of 1A250V in the alternating current incoming line, fuse F1 passes through glass packaging, quick fuse when catastrophe failure occurring, and protective circuit, diode rectifier bridge DB1 carries out rectification to interchange.

The valley fill type pfc circuit is by three diode in series D3, D1, D2 successively in the same way, and be connected the electrochemical capacitor C1 between diode D1 anode and the diode D2 negative electrode, the electrochemical capacitor C2 that is connected between diode D3 anode and the diode D1 negative electrode constitutes.

In the valley fill type pfc circuit; Capacitor C 1, C2 carry out filtering. and diode D1, D2, D3 effect are to fill out the power factor correction of appearance formula, and when input voltage is higher than C1,1/2 last voltage of C2, electric current can flow into the L3D load; When voltage during less than last 1/2 voltage of C1, C2; Diode D2, D3 positive deflection, C1, C2 begin parallel discharge valley fill type pfc circuit and to a certain extent input current are repaired, in the time of can realizing specified output greater than 0.88 power factor (PF).

In the constant-current control circuit; Loop is connected and composed by inductance L 1, sustained diode 4, the sealing of electrochemical capacitor C4 loop; Wherein sustained diode 4 anodes connect inductance L 1; Sustained diode 4 negative electrodes meet electrochemical capacitor C4; Draw the D pin of lead through chip U1 in the loop between inductance L 1, sustained diode 4 anodes and insert the built-in switch mosfet of chip U1, in the loop between sustained diode 4 negative electrodes and the electrochemical capacitor C4, lead to the loop output line respectively, the load of loop output line access external LED between inductance L 1 and the electrochemical capacitor C4.

In the constant-current control circuit, the inner controller of chip U1 is stablized output current through enabling and turn-off the switch mosfet cycle.The switch mosfet alternation of chip U1 inside is in the Push And Release two states, and when switch conduction, the input power supply is through the inner MOSFET switch of chip U1; And 1 pair of LED electric of inductance L; And simultaneously to inductance L 1 charging, ground when the inner MOSFET of sheet U1 turn-offs, the inverse electromotive force in the inductance L 1 makes sustained diode 4 formation loops; The LED load is continued power supply, thereby proof load obtains continuous electric current.

Feedback circuit comprises the parallel circuits that sampling resistor R1 parallel with one another, R3 constitute; And optocoupler OP1; Said parallel circuits is connected on one of them loop output line and inserts between the input pin of optocoupler OP1; Output pin of optocoupler OP1 inserts the FB pin of chip U1, and another output pin of optocoupler OP1 inserts on the BP pin of chip U1, and the BP pin of chip U1 is also through capacitor C 3 ground connection.

In the feedback circuit, optocoupler OP1 model is pc817, and optocoupler OP1 emitter connects the FB pin of chip U1, surpasses 49 μ A as long as get into the electric current of FB pin, and the inner switch mosfet operation of chip U1 just is turned off.R3, R1 are sampling resistor, and its two ends are connected respectively to 1 pin, 2 pin of optocoupler OP1, and when being added in its voltage greater than 1.2V, promptly the input signal of telecommunication of optocoupler OP1 is greater than 1.2V; 1 pin, the 2 pin conductings of optocoupler OP1, photophore emits beam and is radiated on the light-receiving device, and the light-receiving device conducting produces photoelectric current; From expelling plate output, flow into the FB pin of chip U1, when electric current during greater than 49uA; The inner switch mosfet operation of chip U1 just is turned off, and this moment, inductance L 1 interior energy stored was delivered to sustained diode 4, and the LED load forms the loop; The feedback pin FB induced current of chip U1 is during less than 49uA, and the inner switch mosfet operation of chip U1 just is opened

The utility model maximum output voltage is 80V, and maximum output current is 250mA, and peak power can be crossed 15W, is fit to very much drive small-power type LED.

Claims

1. the LED driving power with High Power Factor of the non-isolation of linearity; Include the alternating current incoming line; It is characterized in that: also comprise diode rectifier bridge DB1, valley fill type pfc circuit, be the constant-current control circuit that the loop of chip U1 and the chip U1 control of LNK306 constitutes by model; Said alternating current incoming line inserts diode rectifier bridge DB1 input, and the output of diode rectifier bridge DB1 inserts the valley fill type pfc circuit, and the output of said valley fill type pfc circuit inserts constant-current control circuit; The loop output line inserts the external LED load in the said constant-current control circuit, between loop output line and chip U1, also has access to feedback circuit.

2. the LED driving power with High Power Factor of the non-isolation of a kind of linearity according to claim 1; It is characterized in that: said valley fill type pfc circuit is by three diode in series D3, D1, D2 successively in the same way, and be connected the electrochemical capacitor C1 between diode D1 anode and the diode D2 negative electrode, the electrochemical capacitor C2 that is connected between diode D3 anode and the diode D1 negative electrode constitutes.

3. the LED driving power with High Power Factor of the non-isolation of a kind of linearity according to claim 1; It is characterized in that: in the said constant-current control circuit; Loop is connected and composed by inductance L 1, sustained diode 4, the sealing of electrochemical capacitor C4 loop; Wherein sustained diode 4 anodes connect inductance L 1; Sustained diode 4 negative electrodes meet electrochemical capacitor C4; Draw the D pin of lead through chip U1 in the loop between inductance L 1, sustained diode 4 anodes and insert the built-in switch mosfet of chip U1, in the loop between sustained diode 4 negative electrodes and the electrochemical capacitor C4, lead to the loop output line respectively, the load of loop output line access external LED between inductance L 1 and the electrochemical capacitor C4.

4. the LED driving power with High Power Factor of the non-isolation of a kind of linearity according to claim 1; It is characterized in that: said feedback circuit comprises the parallel circuits that sampling resistor R1 parallel with one another, R3 constitute; And optocoupler OP1; Said parallel circuits is connected on one of them loop output line and inserts between the input pin of optocoupler OP1, and output pin of optocoupler OP1 inserts the FB pin of chip U1, and another output pin of optocoupler OP1 inserts on the BP pin of chip U1.

5. the LED driving power with High Power Factor of the non-isolation of a kind of linearity according to claim 1 is characterized in that: have access to fuse F1 on the said alternating current incoming line.