In the Process control system, the actuator is composed of the actuator and the adjusting mechanism. The adjusting mechanism can directly change the parameters of the production process by executing the components, so that the production process meets the predetermined requirements. The actuator accepts control information from the controller to convert it to the output of the drive regulator (such as angular displacement or linear displacement output). It also uses appropriate actuator components, but requires different regulatory mechanisms. Actuators are installed directly in the production site, sometimes with harsh working conditions. The ability to maintain normal work directly affects the safety and reliability of the automatic control system.
(1) Actuators according to the driving energy is divided into pneumatic, electric and hydraulic actuator three kinds.
(2) According to the output displacement form, the actuator has the angle type and the straight line type two kinds.
(3) According to the action law, the actuator can be divided into three types: switch type, integral type and proportional type.
(4) According to the input control model, the actuator can be divided into the air pressure signal, the DC current signal, the electric contact On-off signal, the pulse signal and so on.