Patent ID: 6542388
Filing Date: 2003-04-01
Classification: H02M

Abstract:
A intermittent switching power supply circuit, comprising:a control terminal controlling an intermittent oscillator and producing an output power; a rectifying-smoothing circuit smoothing said output power; output power monitoring means for monitoring said output power and for sending a stop control to a photocoupler emitter element when said output power exceeds a reference power; a photocoupler receiver element; said photocoupler receiver element photocoupled to said photocoupler emitter element and controlling a control terminal of said intermittent oscillator when said output power exceeds said reference power; protection circuit means for outputting a back-up stop control signal to said control terminal when said output power monitoring means determines that said output power exceeds a reference power; said protection circuit means being connected in parallel with said photocoupler receiver element; and said protection circuit means outputting said back-up stop control signal to said control terminal and stopping said intermittent oscillator when a failure occurs even when said photocoupler receiver element fails to control said intermittent oscillator, whereby said intermittent switching power supply circuit safely controls and stabilizes said output power.