an electronic control system in which a hydraulic, pneumatic, or other type of controlling mechanism is actuated and controlled by a low-energy signal.
A feedback system that consists of a sensing element, amplifier, and servomotor, used in the automatic control of a mechanical device.
A self-regulating feedback system or mechanism: "We do not need to know in detail how the minute chemical servomechanisms of the muscles operate in order to move our arms"(Harper's).