Switching power supply regulator with an inductive pulse circuit

摘要

A horizontal deflection circuit couples flyback pulses from a first transformer winding to a second transformer winding. The second winding is coupled to a source of unregulated DC voltage. A switch has input, output and control terminals. The output terminal is coupled to the first winding. The switch operates with a variable duty cycle for generating a regulated DC voltage at the output terminal. An inductor and a diode are coupled to the second winding. The inductor is also coupled to the input terminal. A pulse width modulator varies the duty cycle of the switch responsive to feedback and timing signals. Drive voltage for the control terminal is supplied by a first capacitor charged during retrace intervals and a second capacitor charged at the end of the retrace intervals by the first capacitor. The second capacitor is coupled to the control terminal and the drive voltage is discharged by the pulse width modulator.