Micro Switches

Micro switches, also known as snap-action switches, are mechanically operated electrical switches designed with an actuator and terminals called common, normally open (NO), and normally closed (NC). They operate using a spring-loaded lever that opens and closes a set of internal contacts inside the unit.

Power is typically attached to the common terminal, which energizes the spring. In its resting state, the spring touches the normally closed pin, sending power out through it. When the actuator arm is moved, the power is transferred to the normally open pin, completing the circuit in a different configuration.

At RS, we offer an extensive range of micro switches from leading brands such as Saia-Burgess, Honeywell, and Crouzet, as well as our own trusted RS PRO range. Our selection includes multiple actuator types, electrical ratings, and mounting options to suit diverse applications. With RS, you can rely on fast delivery and exceptional service to keep your projects on schedule.

Micro Switch Types & Features

Micro switches are available in various actuator styles, each suited for specific applications. They are generally designed for low currents and voltages, making them ideal for control circuits and safety mechanisms. Operating life is typically very high, often measured in millions of cycles, which makes them reliable and cost-effective for both consumer and industrial use. Here are the main types and their features:

• Button Micro Switches – A Button Micro Switch is actuated by pressing a button directly. Ideal for simple on/off control in compact devices.
• Roller Micro Switches – A Roller Micro Switch uses a roller attached to a lever for smooth actuation, commonly used in machinery and conveyor systems.
• Plunger Micro Switches – A Plunger Micro Switch is triggered by a straight push motion, suitable for precision applications like measuring airflow or gas flow.
• Lever Micro Switches – A Lever Micro Switch uses a lever arm for actuation, often found in door interlocks and safety systems.

Micro Switch Applications

Micro switches are widely used in both consumer devices and industrial equipment. Common applications include door interlocks in appliances such as microwave ovens, ensuring the door is closed before power is supplied. They are also used in elevators as safety switches, and in levelling devices for vending machines.

In industrial settings, micro switches are often integrated into control circuits for automation and safety. Sensitive designs can be used in precise equipment, such as systems that measure airflow or gas flow. Their reliability and low cost make them ideal for safety-critical applications where circuit interruption is required to prevent accidents.

For more information, please refer to the Guide to Microswitches.