A limit switch is a sturdy electromechanical sensor that detects when a moving machine part reaches a defined position and consequently starts or stops an electrical circuit. An actuator—such as a lever, roller, or plunger—physically engages with the machine, shifting internal contacts (normally open, closed, or both). These switches are typically encased to resist environmental influences like dust, oil, or water and are widely used in automated systems—from garage doors to injection molding machines and hydraulic cylinders. Their design ensures precise control, enhances machine safety, and offers reliable feedback to control systems.
A built-in proximity switch on the left, a micro limit switch on the right
Related topics:
Roller-lever limit switch
Position switch
End-of-travel sensor
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
