Limit switch

[1] Limit switches are used in a variety of applications and environments because of their ruggedness, ease of installation, and reliability of operation.

They can determine the presence, passing, positioning, and end of travel of an object.

A reed switch may be used to indicate proximity of a magnet mounted on some moving part.

Miniature snap-action switches are components of devices like photocopiers, computer printers, convertible tops or microwave ovens to ensure internal components are in the correct position for operation and to prevent operation when access doors are opened.

A set of adjustable limit switches installed on a garage door opener shut off the motor when the door has reached the fully raised or fully lowered position.

A limit switch with a roller-lever operator; this is installed on a gate on a canal lock , and indicates the position of a gate to a control system
A limit switch mounted on a moving part of a bridge