CN204859610U - LED drive circuit - Google Patents

Abstract

The utility model discloses a LED drive circuit, including rectifier bridge Q, electric capacity C1, diode D1, MOS manages VS, chip U1, resistance R1 and inductance L3, 220V alternating current both ends are connected respectively with rectifier bridge Q pin 4 to rectifier bridge Q pin 2, inductance L3 is connected to rectifier bridge Q pin 1, electric capacity C1 and ground connection are connected to rectifier bridge Q pin 3, the inductance L3 other end is connected respectively to the electric capacity C1 other end, resistance R1, diode D4 is anodal, resistance R5, electric capacity C4 and transformer T coil L1. The utility model discloses LED drive circuit uses chip OB2532, has the high characteristics of stability, adds diode D4 and diode D5 moreover, can arrive the spike voltage clamper that transformer T leakage inductance produced safe value, raising circuitry stability, and circuit structure is simple, and is with low costs, especially adapted using widely.

Description

A kind of LED drive circuit

Technical field

The utility model relates to a kind of LED, specifically a kind of LED drive circuit.

Background technology

In energy crisis and climate warming problem more and more serious today, energy-conservationly become social focus subject under discussion with environmental protection.LED gets more and more people's extensive concerning because of plurality of advantages such as it is efficient, energy-saving and environmental protection, life-span length, rich color, little, the resistance to flicker of volume, reliability are high, regulation and control are convenient, is considered to 21 century the most promising lighting source.Traditional incandescent lamp efficiency is low, power consumption is high; Fluorescent lamp power saving, but useful life is short, frangible, and there is mercury pollution in discarded object; There is the shortcomings such as efficiency is low, power consumption is high, the life-span is short, hazards of electromagnetic radiation in high-intensity gas discharge lamp; If current poor efficiency, the traditional lighting of highly energy-consuming can be replaced with LED illumination, current more and more urgent energy shortage and ecological deterioration problem can be alleviated undoubtedly.Due to voltage-current characteristic and the temperature characterisitic of LED self, make the susceptibility of LED to electric current be higher than susceptibility to voltage, therefore can not be powered directly to LED by traditional power supply.Therefore, make with LED the problem that first lighting source will solve driving, how to provide stability is high, cost is low LED power circuit to become the research direction of Ge great LED producer.

Utility model content

The purpose of this utility model is the LED drive circuit providing a kind of cost low, to solve the problem proposed in above-mentioned background technology.

For achieving the above object, the utility model provides following technical scheme:

A kind of LED drive circuit, comprise rectifier bridge Q, electric capacity C1, diode D1, metal-oxide-semiconductor VS, chip U1, resistance R1 and inductance L 3, described rectifier bridge Q pin 2 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 4, rectifier bridge Q pin 1 connects inductance L 3, rectifier bridge Q pin 3 connects electric capacity C1 and ground connection, the electric capacity C1 other end connects inductance L 3 other end respectively, resistance R1, diode D4 positive pole, resistance R5, electric capacity C4 and transformer T coil L1, diode D4 negative pole connects ground connection diode D5 negative pole, the described electric capacity C4 other end is the contact resistance R5 other end and diode D2 negative pole respectively, the D pole of the diode D2 positive pole difference connection transformer T coil L1 other end and metal-oxide-semiconductor VS, the G pole of metal-oxide-semiconductor VS connects the GATE pin of chip U1, the S pole of metal-oxide-semiconductor VS connects the CS pin of earth resistance R4 and chip U1 respectively, the COMP pin of chip U1 connects electric capacity C3, electric capacity C3 other end contact resistance R3 ground connection, the resistance R3 other end connects INV pin and the resistance R2 of chip U1 respectively, the resistance R2 other end connects diode D3 positive pole and transformer T neutral earthing compensator L4 respectively, diode D3 negative pole connects ground capacity C2 respectively, the VDD pin of the resistance R1 other end and chip U1, described transformer T coil L2 one end connects diode D1 positive pole, the transformer T coil L2 other end connects electric capacity C5 and resistance R6 respectively, the resistance R6 other end connects diode D1 negative pole respectively, the electric capacity C5 other end and ground connection LED positive pole.

As further program of the utility model: described chip U1 model is OB2532.

As the utility model further scheme: described diode D5 is voltage stabilizing didoe.

Compared with prior art, the beneficial effects of the utility model are: the utility model LED drive circuit uses chip OB2532, have the advantages that stability is high, and add diode D4 and diode D5, the peak voltage clamper that transformer T leakage inductance can be produced is to safety value, and promote circuit stability, circuit structure is simple, cost is low, is applicable to very much promoting the use of.

Accompanying drawing explanation

Fig. 1 is the circuit diagram of LED drive circuit.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.

Refer to Fig. 1, in the utility model embodiment, a kind of LED drive circuit, comprise rectifier bridge Q, electric capacity C1, diode D1, metal-oxide-semiconductor VS, chip U1, resistance R1 and inductance L 3, rectifier bridge Q pin 2 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 4, rectifier bridge Q pin 1 connects inductance L 3, rectifier bridge Q pin 3 connects electric capacity C1 and ground connection, the electric capacity C1 other end connects inductance L 3 other end respectively, resistance R1, diode D4 positive pole, resistance R5, electric capacity C4 and transformer T coil L1, diode D4 negative pole connects ground connection diode D5 negative pole, the electric capacity C4 other end is the contact resistance R5 other end and diode D2 negative pole respectively, the D pole of the diode D2 positive pole difference connection transformer T coil L1 other end and metal-oxide-semiconductor VS, the G pole of metal-oxide-semiconductor VS connects the GATE pin of chip U1, the S pole of metal-oxide-semiconductor VS connects the CS pin of earth resistance R4 and chip U1 respectively, the COMP pin of chip U1 connects electric capacity C3, electric capacity C3 other end contact resistance R3 ground connection, the resistance R3 other end connects INV pin and the resistance R2 of chip U1 respectively, the resistance R2 other end connects diode D3 positive pole and transformer T neutral earthing compensator L4 respectively, diode D3 negative pole connects ground capacity C2 respectively, the VDD pin of the resistance R1 other end and chip U1, transformer T coil L2 one end connects diode D1 positive pole, the transformer T coil L2 other end connects electric capacity C5 and resistance R6 respectively, the resistance R6 other end connects diode D1 negative pole respectively, the electric capacity C5 other end and ground connection LED positive pole.

Chip U1 model is OB2532.

Diode D5 is voltage stabilizing didoe.

Operation principle of the present utility model is: refer to Fig. 1 and input 220V alternating current through bridge rectifier, inductance L 3, electric capacity C1 filtering, direct voltage is added to transformer T coil L1, receive the drain electrode of metal-oxide-semiconductor VS again, transformer T coil L4 is through diode D3 rectification, electric capacity C2 is filtered into chip U1 and provides power supply, transformer T coil L4 is also for chip U1 end of oppisite phase INV provides feedback voltage simultaneously, the sensed current signal of the source resistance R4 of metal-oxide-semiconductor VS is added on the CS pin of chip U1, under these two kinds of signal controlling, the pulse duration of the gate drive signal being input to metal-oxide-semiconductor VS is adjusted, to reach the object of constant current.The former limit of transformer is connected to buffer network, be made up of diode D2, resistance R5 and electric capacity C4, access diode D2 can make inverse peak voltage consume its energy by diode D2 and resistance R5, reduce inverse peak voltage, in order to avoid the too high voltages occurred on transformer T coil L1 in switching process damages power MOS pipe VS, diode D4 and diode D5, the peak voltage clamper that transformer T leakage inductance can be produced, to safety value, promotes circuit stability.

To those skilled in the art, obvious the utility model is not limited to the details of above-mentioned one exemplary embodiment, and when not deviating from spirit of the present utility model or essential characteristic, can realize the utility model in other specific forms.Therefore, no matter from which point, all should embodiment be regarded as exemplary, and be nonrestrictive, scope of the present utility model is limited by claims instead of above-mentioned explanation, and all changes be therefore intended in the implication of the equivalency by dropping on claim and scope are included in the utility model.Any Reference numeral in claim should be considered as the claim involved by limiting.

In addition, be to be understood that, although this specification is described according to execution mode, but not each execution mode only comprises an independently technical scheme, this narrating mode of specification is only for clarity sake, those skilled in the art should by specification integrally, and the technical scheme in each embodiment also through appropriately combined, can form other execution modes that it will be appreciated by those skilled in the art that.

Claims (3)

1. a LED drive circuit, comprise rectifier bridge Q, electric capacity C1, diode D1, metal-oxide-semiconductor VS, chip U1, resistance R1 and inductance L 3, it is characterized in that, described rectifier bridge Q pin 2 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 4, rectifier bridge Q pin 1 connects inductance L 3, rectifier bridge Q pin 3 connects electric capacity C1 and ground connection, the electric capacity C1 other end connects inductance L 3 other end respectively, resistance R1, diode D4 positive pole, resistance R5, electric capacity C4 and transformer T coil L1, diode D4 negative pole connects ground connection diode D5 negative pole, the described electric capacity C4 other end is the contact resistance R5 other end and diode D2 negative pole respectively, the D pole of the diode D2 positive pole difference connection transformer T coil L1 other end and metal-oxide-semiconductor VS, the G pole of metal-oxide-semiconductor VS connects the GATE pin of chip U1, the S pole of metal-oxide-semiconductor VS connects the CS pin of earth resistance R4 and chip U1 respectively, the COMP pin of chip U1 connects electric capacity C3, electric capacity C3 other end contact resistance R3 ground connection, the resistance R3 other end connects INV pin and the resistance R2 of chip U1 respectively, the resistance R2 other end connects diode D3 positive pole and transformer T neutral earthing compensator L4 respectively, diode D3 negative pole connects ground capacity C2 respectively, the VDD pin of the resistance R1 other end and chip U1, described transformer T coil L2 one end connects diode D1 positive pole, the transformer T coil L2 other end connects electric capacity C5 and resistance R6 respectively, the resistance R6 other end connects diode D1 negative pole respectively, the electric capacity C5 other end and ground connection LED positive pole.

2. LED drive circuit according to claim 1, is characterized in that, described chip U1 model is OB2532.

3. LED drive circuit according to claim 1, is characterized in that, described diode D5 is voltage stabilizing didoe.