What is an Actuator

An actuator is a functional element which connects the information processing part of an electronic control system with a technical or nontechnical part, e. g. biological, process. Actuators can be used to control the flow of energy, mass or volume. The output of an actuator is energy or power, often available in the form of a mechanical working capacity force times displacement . The actuator input is always driven by very low electrical power, ideally without any power consumption, with currents and voltages which are, if possible, microelectronically (e. g. TTL) compatible [1]. 

DIN standard final controlling equipment ( Stelleinrichtung ) and final controlling element ( Stellglied ). It is worth noting that the term actuator used in Fig. 6.2 conflicts with the actuator definition presented above which shall serve as the basis for this chapter. 

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