Abstract: A digital controller includes a digital feedback circuit for use in generating a pulse-width modulated control signal. The signal is derived from binary signals representing a standard pulse-width signal for the rated output of the power supply plus a correction pulse-width signal reflecting the change in the output level of the power supply. Logic circuits alter the correction pulse-width signals to provide a balancing correction. Soft start operation of the power supply together with a selection of operating clock frequencies are also provided.

Abstract: A digital controller for a power supply which includes a transformer having primary and secondary windings and switching transistors for switching a current from a D.C. input means through the winding of the transformer to an output circuit. Pulse-width modulated control signals are used to control the switching operation of the transistors. In order to correct for an imbalance in the operation of the transistors, an error signal is developed which alters the value of the duty cycle of the transistors forcing the B-H curve of the transformer to oscillate between upper and lower threshold values.