What is the actuator

What is the actuator？

Actuator is an essential part of automatic control system. Its function is to receive the control signal from the controller, change the size of the controlled medium, so as to maintain the controlled variable in the required value or a certain range. According to its energy form, actuators can be divided into three categories: pneumatic, hydraulic and electric. Compressed air is used as energy source for pneumatic actuator, which is characterized by simple structure, reliable action, smooth operation, large output thrust, convenient maintenance, fire and explosion prevention, and low price. Therefore, it is widely used in chemical industry, papermaking, oil refining and other production processes, and can be easily used with passive instruments. Even if the electric instrument or computer control is used, as long as the electrical signal is converted into 20-100kpa standard pressure signal through the electro pneumatic converter or electro pneumatic valve positioner, the pneumatic actuator can still be used. The electric actuator has the advantages of easy access to energy and rapid signal transmission, but it has complex structure and poor explosion-proof performance. The hydraulic actuator is not used in the chemical industry, oil refining and other production processes. Its characteristic is that the output thrust is very large.