Abstract: A circuit for regulating the output of a DC power supply that substantially eliminates turn-on transients induced by the switching of a silicon-controlled rectifier (SCR). A zero-crossover detector senses the AC voltage waveform of an applied power source and provides a trigger signal at the zero-crossing point. The trigger signal is applied to cause induction of the SCR's and raise the output voltage when the power supply output drops below a regulated value, and is interrupted so as to inhibit conduction of the SCR's and decrease the output voltage when the power supply output exceeds the regulated value.

Abstract: A presettable counter and a substantially identical counter both slaved to a crystal-controlled clock oscillator form a programmable slip counter for providing transition signals with a time interval therebetween in accordance with a coarse delay signal preset into the presettable counter. A programmable logic delay line responsive to a fine delay signal delays one of the transitions so as to impart a precise delay interval between the delayed transition signal and the other transition signal.