- noun a device that supplies a small current to the windings of a larger electrical motor
- noun the source of a small current to supply electrical current to the windings of larger electrical motors, etc., e.g. a battery
- A component, circuit, or device which provides excitation (1).
- An oscillator which generates the carrier frequency of a transmitter.
- A part of an antenna which is driven directly by the transmission line.
- A small auxiliary generator which supplies field current for an AC generator.
- A probe or loop which projects into a resonant cavity or waveguide.