Solenoid is an Electro-mechanical device which combines together electro-magnetic control with movement.
Solenoids are made of several basic elements: Winding/cylindrical ring, metal housing and a metal plunger. While current flowing through the winding, a magnetic field is being created, The casing around the winding enables magnetic flux transition and focuses the magnetic field around the plunger. The plunger, which is made of magnetic material, reacts to the magnetic field by moving to the center of the winding.
DC voltage solenoids are not able to change direction of the magnetic field and force since the current is direct. There are AC voltage solenoids which can change direction of the magnetic field. Solenoids are designed to push or pull load through a certain stroke at a certain period of time.
Rotational Solenoids – Rotational solenoids are similar to the linear solenoids in their mechanism, however they are creating a rotational movement with the help of additional miniature balls which converting the linear movement to rotational.
Solenoids are often used in the medical and defense industries. Rotational solenoids provides a compact, simple and cost effective solutions whenever torque is needed.