An over-power protection apparatus for self-excited power converter
comprises a soft-start unit, an adjusting unit and a timing unit. A PWM
unit of the self-excited power converter generates a switching signal in
response to a compensating signal of the soft-start unit to control the
output power of the self-excited power converter. The soft-start unit
couples to the adjusting unit. The adjusting unit drives the soft-start
unit and the PWM unit for modulating the switching signal to reduce the
pulse width of the switching signal and the output power of the
self-excited power converter once the short-circuit and over-load are
happened at the output of the self-excited power converter. In the
meantime, a timing unit starts to count. The timing unit drives the
self-excited power converter to stop supplying the power source after the
counting and the over-power lasting for a period of time.