Switching driver overload protection circuit

摘要

A circuit for protecting a field current transistor 28' for a generator, comprises means 182,184 for controlling current through the transistor, and a relaxation oscillator 180 for reducing the current in response to increasing load. The control may be a PWM gate drive signal. The oscillator changes the gate drive signal duty cycle in response to the load current. The oscillator 180 includes a comparator 190 operating with hysteresis.