A limit switch is one of the most basic mechanical / electronics components on a production floor. They are used for object detection and machine / personnel safety. The limit switch will send a signal to a control circuit once it is in a certain position.

There are 4 general types of limit switches: 1. Whisker. 2. Roller. 3. Lever. 4. Plunger. Depending on the application, a limit switch may be a combination of 2 of the general types such as roller-lever. What are limit switches? A limit switch is an electromechanical device operated by a physical force applied to it by an object.

Switch Symbols. These devices are used to allow, interrupt or divert the passage of electrical current.

In electrical engineering, a limit switch is a switch operated by the motion of a machine part or the presence of an object. A 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.

When the limit switch is actuated by the presence or movement of an object, the contacts close, completing the circuit and allowing current to flow. State at Rest: The contacts are open, and the circuit is incomplete. Actuation: When triggered (e.g., by an object pressing against the switch’s lever or plunger), the contacts close.