SWITCHING POWER SUPPLY REGULATOR

摘要

A horizontal deflection circuit inductively couples pulses from a first winding of a transformer to a second winding of the transformer. The second winding is coupled to a source of unregulated DC voltage. A switch operates with a variable duty cycle, supplying a regulated DC voltage to the first winding. An inductor and a diode have a common junction coupled to the second winding. The inductor couples the unregulated DC voltage to the switch. A pulse width modulator varies the duty circle of the switch responsive to a feedback signal. First and second capacitors supply drive voltage to the switch. The first capacitor is charged by the unregulated DC voltage during retrace, and at the end of retrace, charges the second capacitor. The pulse width modulator discharges the second capacitor.