KR970008765A

KR970008765A - Power stage protection circuit

Info

Publication number: KR970008765A
Application number: KR1019950023398A
Authority: KR
Inventors: 노수현
Original assignee: 배순훈; 대우전자 주식회사
Priority date: 1995-07-31
Filing date: 1995-07-31
Publication date: 1997-02-24

Abstract

본 발명은 전원단 보호회로에 관한 것으로, 2차 부하가 오픈되지 않은 경우, 포토 커플러에 의해 제2트랜지스터의 베이스단자에 하이레벨 신호가 제공되므로 제2트랜지스터가 턴온되어 정류평활부에서 정류 및 1차 평활된 전원이 변압부로 제공되고, 2차 부하로 소망하는 소정전압의 직류가 제공되는 중에 2차 부하가 오픈되는 경우, 포토 커플러에 의해 제2트랜지스터의 베이스단자에 로우레벨 신호가 제공되므로 제2트랜지스터는 턴오프되어 정류평활부에서 정류 및 1차 평활된 전원이 변압부로 제공되지 않으므로써, 2차 부하가 오픈되는 경우, 외부로부터 전원을 차단하므로, 전원단을 보호함은 물론 오픈시의 전력손실을 막을 수 있고, 사용자의 감전위험을 사전에 막을 수 있도록 한 것이다.The present invention relates to a power stage protection circuit, and when the secondary load is not open, the high level signal is provided to the base terminal of the second transistor by the photo coupler, so that the second transistor is turned on to rectify and rectify the rectifier smoothing unit. When the secondary smoothed power is supplied to the transformer and the secondary load is opened while the DC of the desired voltage is supplied to the secondary load, a low level signal is provided to the base terminal of the second transistor by the photo coupler. Since the second transistor is turned off and the rectified and primary smoothed power is not provided to the transformer, the secondary load is disconnected from the outside when the secondary load is opened, thus protecting the power stage and opening. It can prevent power loss and prevent user's risk of electric shock in advance.

Description

Power stage protection circuit

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is an open matter, no full text was included.

제1도는 본 발명의 바람직한 실시예에 따른 전원단 보호회로도.1 is a power supply protection circuit diagram according to a preferred embodiment of the present invention.

Claims

Rectifying smoothing means 10 for rectifying the power from the outside and then smoothing the primary and the transformer means for converting the rectified and primary smoothed power to the desired voltage in the rectifying smoothing means 10 and the In the power supply circuit for providing a smoothing means 30 for secondary smoothing the voltage transformed by the transformer means 20 and the power smoothed by the smoothing means 30 to the secondary load 40, the smoothing means And a switching means for detecting the secondary smoothed power at 30 and switching the power supply from the rectifying smoothing means 10 to the transformer means 20 accordingly. Circuit.

2. The apparatus of claim 1, wherein the switching means comprises: first switching means for switching based on a voltage smoothed in the secondary smoothing means; And a second switching means for switching the power supply from the rectifying smoothing means to the transformer means based on the switching signal from the first switching means.

3. The apparatus of claim 2, wherein the first switching means comprises: third switching means for switching the supply of voltage to the fourth switching means based on the voltage smoothed in the secondary smoothing means; The fourth switching means for switching based on the switching signal from the third switching means; And a fifth switching means for generating a switching signal to the fourth switching means based on the switching signal from the third switching means.

4. The power terminal protection circuit according to claim 3, wherein said third switching means is a diode (D2).

4. The power supply protection circuit according to claim 3, wherein the fourth switching means is a transistor (TR3).

4. The power supply protection circuit according to claim 3, wherein the fifth switching means is a photo coupler (60).

The power supply protection circuit according to claim 2, wherein the second switching means is a transistor (TR2).

※ Note: The disclosure is based on the initial application.