What are the Functions of a Limit Switch?

Limit switches are used widely in industrial settings and consumer products. They turn on a car's overhead lights when its door is opened or unlocked, and assembly lines depend on limit switches for safety monitoring.


A switch that limits the activation of an electrical circuit is a limit switch. Switches can control the flow of electrical current by opening and closing. When a circuit is closed, it allows electrical current to flow to the device that is powered. When open, the electrical flow stops.


In most cases, a limit switch opens and closes based on a device's position. It is often linked to timing as well. In manufacturing, a limit switch may open and turn off a device that doesn't complete a task in a specific amount of time.

Mechanical Type

The most common switches, mechanical limit switches keep track of items. When a device, or part of a device, reaches a certain location, its limit switch opens or closes. The switch depends on physical contact, or the lack of it, to open or close. An example is refrigerator light that switches off when the door closes and turns on when it opens.

Centrifugal Type

A centrifugal limit switch is activated by the speed of the device it monitors. It is often a safety feature, shutting down the device if it exceeds a set speed. In industrial settings, it helps to control assembly lines, industrial robots and fire safety doors.

About the Author

Mark Vallet is a a stay-at-home dad who began freelance writing in 2009. He has produced online content for Demand Studios, Autos.com and CarsDirect.com. He has traveled extensively within the U.S. and internationally. Vallet holds a Bachelor of Arts in English literature from the University of Iowa.