A remote actuator is a device designed to supply the output motion needed to switch, move, or adjust a secondary mechanism in a position removed from the control source. For example, when a gate opener is activated by the driver of a car approaching the gate, the motor and gear arrangement that opens the gate is deemed to be a remote actuator. Remote actuators may be powered by an electric current, compressed gas, or compressed fluid, and may be controlled by a simple remote push button or an elaborate and sophisticated computerized interface. The remote actuator may be situated a couple of inches or several miles away from the control input source depending on the particular application. These actuators are usually used where physical activation of the secondary mechanism by an operator is not practical or safe, and are found in wide variety of domestic, industrial, and manufacturing environments.
The term remote actuator is actually somewhat of an overstatement as an actuator is, by definition, a remote activation device. The term is, however, widely used to describe a range of devices used to supply remote or automated actuation of secondary mechanism. In general, the defining characteristics of the remote actuator are fairly simple. The device must supply working motion used to activate a secondary device and must do so without any operator intervention in the supply of that motion. This applies if the actuator itself is physically started by an operator or by an automated system input.
Remote actuators come in a wide range of sizes, output orientations, and torque ratings, and may be activated by a variety of power sources. These include electric current in the case of electromagnetic and motor-driven electromechanical actuators, and compressed gas or oil in the case of pneumatic and hydraulic types, respectively. Output orientation is usually linear or rotary with rotary remote actuator models being divided into multi-turn motor driven types and quarter-turn hydraulic or pneumatic types. Actuator sizes and torque capabilities range from tiny instrument solenoids to huge hydraulic earth-moving machinery rams.
The typical application of a remote actuator is a working environment where direct, physical operator intervention is either impractical or unsafe. These include small internal instrument or machine spaces, extensive installations where components are located far from staff stations, and corrosive, hot, or explosive working conditions. As a matter of fact, it is difficult to think of an industry or application that does not feature one or other type of remote actuator.