Devices and methods for detecting operational failures of relays

摘要

An uninterruptible power supply (UPS) includes a power conversion circuit and a relay. The relay is configured to couple and decouple a power source to and from an input of the power conversion circuit. The control circuit is operative to apply a coil current to the relay to sense the coil current and to detect an operational failure of the relay from the sensed coil current. Related methods of operating such UPSs are also provided.