Servomechanism

A servomechanism (or more simply a servo) is an electromagnetic device that converts electricity into controlled motion using negative feedback mechanisms. It can generate linear or circular motion depending on its type. It consists of a mechanical device, such as an electric motor, that is connected to a sensor and a controller. The sensor measures the output of the system and sends it to the controller, which then adjusts the input to the system in order to keep the sensor's output within given parameters.