Flex Ltd.
Automatic AC feed control (AFC) with zero voltage/current switching

Abstract:

A power converter with AFC (Automatic AC Feed Control) implements zero voltage switching when switching from a first input power supply to a second input power supply. The power converter with AFC includes a relay switchover circuit and control circuitry for selectively providing power to a connected power converter. The control circuitry uses sensed amplitude and phase values for the two input power supplies for determining when the first input power supply is lost and selectively connecting the second input power supply according to precise timing control to minimize component stress.