LIMIT SWITCH

Limit switches are Mechanical Switch which is used to make or break an electrical circuit during certain positions of a repetitive movement. The Basic purpose of a limit switch is to switch discrete outputs on or off based on the position of a rotating shaft. The point at which an output switches on or off, called setpoints, are defined by the engineer at the time of Installation. The limit switches are purely mechanical devices that consisted of Cams attached to a shaft. See Figure 1.1. When a motor rotated the shaft, the cams hit against switches, turning the outputs on and off.

The Limit Switch uses the contacts to determine the position of the shaft. The Contacts then compares this position to previous setpoints and determines if its outputs should be on or off.

Switches are commonly employed as input devices to indicate the presence or absence of a particular condition in a system or process that is being monitored and/or controlled. In motorized electromechanical systems, limit switches provide the function of making and breaking electrical contacts and consequently electrical circuits. A limit switch is configured to detect when a system’s element has moved to a certain position. A system operation is triggered when a limit switch is tripped.