exciters

An exciter is a device or system that provides excitation—energy or a signal—to another component or structure to initiate or sustain some response. In engineering, exciters are used wherever a system requires a source of energy beyond what the primary components provide.

Electrical power generation: In electric power stations, an exciter supplies the direct current to the rotor windings of a synchronous generator to establish its magnetic field. Exciters may be rotating units with rectifiers or static (brushless) systems controlled by a voltage regulator, enabling fast and stable field current control.

Radio and communications: In transmitters, an RF exciter generates the initial carrier signal or a stabilized reference that is then amplified and modulated. An exciter may include oscillators and modulators, and may be part of a phase-locked loop or frequency synthesizer.

Audio processing: In audio technology, an exciter is a processor that adds high-frequency content to a signal to enhance presence, clarity or brightness. Modern exciters use harmonic synthesis or dynamics-based methods, and are common in mixing and mastering gear as plugins or hardware units.

Vibration testing and structural dynamics: Electromechanical exciters or shakers apply controlled forces to a structure to study response or perform modal testing. They are driven by power amplifiers and controlled by test systems, and may operate across a range of frequencies.

The term is thus used across fields to denote a source that produces energy or a signal to provoke a reaction in another part of a system.