Electromagnetic Actuator

Actuators (also called as power transducers) are electrical devices that transform input energy (control variable) to output mechanical work (acting variable). A special type of actuator is the electromagnetic actuator. Control variable of this actuator is electric current and acting variable is force interaction and its effects. The principle of transformation in these actuators is based on force interaction in a magnetic field. Electromagnetics actuators are used in many applications (from small devices for a very precise control of position to quite powerful units such as drives of rods in nuclear reactors).

The solved actuator consists of two basic parts – electric and magnetic circuits. The electric circuit is formed by a cylindrical coil wound fixed on the frame. The magnetic circuit is formed by the shell and movable core. Movable core is placed on the axis of the actuator and can move freely in it. To reduce the friction force between the moving core and shell as well as to prevent their mutual impact the core is placed in a nonmagnetic sliding tube. The current in the coil produces magnetic field that gives rise to the Maxwell force which acts on the ferromagnetic core.

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  • Doležel, I., Karban, P., Kropík, P., Kotlan, V., Pánek, D., : Optimized control of field current in thermoelastic actuator for accurate setting of position, Applied Mathematics and Computation, 2013, Volume 219, Issue 13, pp 7187-7193, DOI 10.1016/j.amc.2011.06.008