Patent attributes
A cat-ear power supply is operable to generate a DC voltage and draws current from an AC power source near the beginning and end of a half-cycle of the AC power source. A controllably conductive switching circuit selectively charges an energy storage capacitor to produce the DC voltage and become conductive to charge the energy storage capacitor near the beginning of the half-cycle of the AC power source. A latch circuit controls the controllably conductive switching circuit to become non-conductive in response to the magnitude of the DC voltage. A switch voltage monitor circuit controls the controllably conductive switching circuit to become non-conductive and resets the latch circuit when the magnitude of a switch voltage across the switching circuit exceeds a predetermined switch voltage threshold. The switching circuit becomes conductive to charge the energy storage capacitor near the end of the half-cycle when the magnitude of the switch voltage drops below the predetermined switch voltage threshold.