Transistor switching regulator control utilizing charging of bootstrap circuit to provide ramp-up

摘要

A transistor switching regulator having a pulse width control which includes a minimum pulse output, a "ramp-up" start pulse output and a feedback controlled running pulse output sequenced to start up and run the transistor switching regulator in a controlled manner. The three pulse outputs are derived from an emitter coupled astable multivibrator having a linearizing boot strap circuit, coupled to one of its emitter output circuits and having a long time constant for gradually charging the capacitor of the boot strap circuit during the ramp-up operation. A circuit which is sensitive to the boot strap circuit during the charging of its capacitor provides a sequence of pulses of gradually increasing width during the ramp-up operation.