What are Micro switches?

Micro switches are mechanically operated electrical switches designed with an actuator and terminals called common, normally open and normally closed. A micro switch is also known as a snap action switch, they operate by using a spring loaded lever to open and close a set of internal contacts inside the unit.

How does a micro switch work?

Power is typically attached to the common terminal, this leads into the switch and energises the spring and because the spring is touching the normally close pin it sends power out here, this is called a resting state. Once the arm is moved the power is then transferred to the normally open pin.

What type of applications need micro switches?

Micro switches are used in consumer devices and industrial equipment. Common application for these devices are in door interlocks, microwave ovens or where a door has to be shut before the power to the device will turn on. Micro switches are also used in leveling devices, such as those used on vending machines. In an elevator, these devices are used in the door as a safety switch.

Micro switches can be designed to be very sensitive. Such designs can be used in very precise equipment, such as that which measures the flow of air or other gasses through a system. These devices are used extensively in industry, often in control circuits.