CN2682729Y

CN2682729Y - A power circuit

Info

Publication number: CN2682729Y
Application number: CNU2003201153001U
Authority: CN
Inventors: 李鸿安; 李海鹰; 戴奇峰; 李�远
Original assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Current assignee: Shenzhen Skyworth Digital Technology Co Ltd
Priority date: 2003-12-03
Filing date: 2003-12-03
Publication date: 2005-03-02
Anticipated expiration: 2013-12-03

Abstract

The utility model relates to a power circuit, disclosing a power circuit, and comprising a power factor correction circuit 1. The power factor correction circuit 1 comprises an MOSFET3 and a buffering unit 2 used for repressing the crest voltage between the drain electrode and the source electrode of the MOSFET3; the buffering unit 2 is connected between the drain electrode and the source electrode of the MOSFET. The utility model has low cost and good reliability, and the supply of goods can be ensured.

Description

A kind of power circuit

Technical field

The utility model relates to a kind of power circuit, specifically, relates to the circuit of power factor correction in a kind of power circuit.

Background technology

At present, the circuit of power factor correction that design has pair power factor to proofread and correct in a lot of power circuits, its scheme is to use a PFC chip or expensive high-precision power field effect pipe to realize power preset, but these two kinds of parts all are difficult for purchasing, price high and delivery date does not guarantee, cause the cost of whole power circuit to raise like this, the risk of production increases.In order to reduce cost, guarantee the source of goods, some producer uses general MOSFET (metal-oxide-semiconductor field effect t) to replace above-mentioned two kinds of parts.Find that in use though the phenomenon of puncture short is fewer mutually between the grid G of MOSFET and drain D, source S, drain electrode is easy to breakdown burning out with source electrode, the phenomenon of its drain electrode and source electrode (D-S) short circuit is commonplace, causes the power circuit poor reliability.

Summary of the invention

The purpose of this utility model provides the power circuit that a kind of cost is low, can guarantee the source of goods and good reliability.

For achieving the above object, the utility model proposes a kind of power circuit, comprise circuit of power factor correction 1, described circuit of power factor correction 1 comprise MOSFET 3 and be used to suppress the drain electrode of MOSFET 3 and source electrode between the buffer cell 2 of crest voltage, described buffer cell 2 is connected between the drain electrode and source electrode of MOSFET.

Described buffer cell 2 is for including the circuit of resistance R and capacitor C series connection.

The beneficial effects of the utility model are: by circuit analysis, the reason of drain electrode and source breakdown is that the transient voltage between drain electrode and the source electrode is too big, be that the real work magnitude of voltage is greater than its rated value, so buffer circuit of series connection between drain electrode and source electrode, can suppress to drain and source electrode between crest voltage.Thereby both guaranteed to use the feasibility of the MOSFET of inexpensive, ample supply and prompt delivery, can guarantee the reliability of power circuit again.

Feature of the present utility model and advantage will be elaborated in conjunction with the accompanying drawings by embodiment.

Description of drawings

Fig. 1 represents power circuit diagram of the present utility model;

Fig. 2 represents circuit of power factor correction figure of the present utility model.

Embodiment

As shown in Figure 1, the utility model comprises circuit of power factor correction 1, described circuit of power factor correction 1 comprise MOSFET 3 and be used to suppress the drain electrode of MOSFET 3 and source electrode between the buffer cell 2 of crest voltage, described buffer cell 2 is connected between the drain electrode and source electrode of MOSFET.

Be illustrated in figure 2 as an embodiment of the present utility model, described buffer cell 2 is for including the circuit of resistance R and capacitor C series connection.When MOSFET pipe turn-offed, capacitor C was charged to the voltage of (Vds-Vr) by resistance R, and drain current has had shunt like this, and drain current can reduce quickly.When the conducting of MOSFET pipe, capacitor C is by resistance R and MOSFET tube discharge.

Buffer cell 2 of the present utility model also can be realized by other modes, for example simple integrated circuit.

RC buffer cell of the present utility model has consumed superfluous shutoff energy, has expanded the load line of MOSFET, has increased its reliability.

Claims

1. power circuit, comprise circuit of power factor correction (1), described circuit of power factor correction (1) comprises MOSFET (3), it is characterized in that: also comprise the buffer cell (2) of crest voltage between the drain electrode that is used to suppress MOSFET (3) and the source electrode, described buffer cell (2) is connected between the drain electrode and source electrode of MOSFET.

2. power circuit as claimed in claim 1 is characterized in that: described buffer cell (2) is for including the circuit of resistance (R) and electric capacity (C) series connection.

3. power circuit as claimed in claim 2 is characterized in that: the resistance of described resistance (R) is 10 Europe, and the appearance value of electric capacity (C) is 100pF.