Limit Switches

In electrical engineering, a limit switch is a switch operated by the motion of a machine part or the presence of an object. More precisely, a limit switch is an electromechanical device that consists of an actuator mechanically linked to a set of contacts. When an object comes into contact with the actuator, the device operates the contacts to make or break an electrical connection.

Limit switch can be used for controlling machinery as part of a control system, as a safety interlock, or as a counter enumerating objects passing a point.