Alternative terms for limit switches are position switches, end switches or end position switches. These switches function as sensors that detect the position of a moving object, such as a machine part or door, and trigger a switching process depending on the position. They initiate a position-dependent action by opening or closing a circuit. The position is detected by various kinds of mechanical actuators, such as switching levers, roller levers or telescopic plungers. Moving these actuators opens or closes the circuit connected to the switch. It is also possible to switch between circuits (changeover).

The switches are used wherever moving machine processes need to be reliably detected, monitored and controlled. A typical area of application is control and automation technology in mechanical and plant engineering. Position switches open or close control circuits and auxiliary circuits, and are used to limit movement or detect the position of control cabinet doors, garage doors or roller shutters, for example. Further applications include configuring a predefined end position of a machine tool (for example, a drilling machine) or securing maintenance openings on machines and electrical devices.

Limit switches from ASA-Schalttechnik are made of high-quality materials. The switches are functional, robust, reliable and precise. To suit a wide variety of applications, position switches are available for different current types and switching capacities and with different switching paths and actuating forces. The large selection of actuator types combined with numerous switch inserts fulfils the requirements of every sector and industry. Thanks to their compact construction, they do not take up much space. The limit switches offer outstanding performance in a small space. ASA-Schalttechnik differentiates between the following four series:

• SK series
• SM series
• SDK series
• SDM series

Position switches in the SK series are available with twelve different plastic actuators. These are a series of stackable limit switches in the form of sub-miniature switches with various switch inserts and multiple power levels and switching systems.

The sub-miniature limit switches in the SM series differ from the SK series in that they feature a metal actuator in one of 47 different variants.

SDK and SDM limit switches are sub-miniature switches in a double construction with two switch inserts and different plastic (SDK) or metal (SDM) actuators. They switch two separate circuits.

For exceptional atmospheric conditions, extremely high or low temperatures or other special requirements, limit switches can be supplied as individual solutions and in special variants.