A circuit includes a solid-state relay, a rectifier, and a current transformer-based power supply. The rectifier is adapted to be coupled to the solid-state relay. The rectifier is configured to provide a voltage to an output terminal responsive to the solid-state relay being in an off state. The current transformer-based power supply is coupled to the rectifier and is adapted to be coupled to a transformer. The current transformer-based power supply is configured to provide a voltage to the output terminal responsive to the solid-state relay being in an on state.