| 摘要 |
In a regulated power supply in which the value of the D.C. output voltage B + is fed back to control the duty cycle of a pulse train controlling a switching circuit 24, a protective circuit 52-58 inhibits operation of the supply if the duty cycle increases to a value indicative of failure of the supply to produce a minimum desired output voltage. Operation of the supply is inhibited for a predetermined shutdown interval (54) following which the protective circuit is deactivated for a period (58) to allow the supply to attempt to establish its desired output. The power supply includes a master oscillator (20) and the protective circuitry (50) inhibits operation of the supply when the D.C. output from the oscillator (20) falls below a preset limit. <IMAGE> |
