A state indicating that a device has transitioned from an off or blocking state into an active, conducting state. For mechanical switches, it means the contacts are closed. For solid-state devices like transistors or thyristors, it means the gate threshold has been exceeded and current is flowing through the main channel. Technicians use this phrase to confirm a power rail is live or a specific sub-circuit has been activated by the control logic.
Heard on the job
The main relay is turned on, but I'm still not seeing any voltage at the load terminals.