Rotary switch

These are often chosen when more than 2 positions are needed, such as a three-speed fan or a CB radio with multiple frequencies of reception or "channels".

A rotary switch consists of a spindle or "rotor" that has a contact arm or "spoke" which projects from its surface like a cam.

The cams are notched or cut where the contact should close to complete an electrical circuit.

Some rotary switches are user-configurable in relation to the number of positions.

A special toothed washer that sits below the holding nut can be positioned so that the tooth is inserted into one of a number of slots in a way that limits the number of positions available for selection.

Three-deck rotary switch allows controlling three different circuit functions.