Rotary switches are switches operated by rotationes. These are often chosen when more than 2 positions are needed, such as a three-speed fan or a radio with multiple frequencies of reception or "channels".
Automotive Rotary Switches consist of a spindle or rotor that has a contact arm or "spoke" which projects from its surface like a cam. It has an array of terminals, arranged in a circle around the rotor, each of which serves as a contact for the "spoke" through which any one of a number of different electrical circuits can be connected to the rotor. Rotary Switch Types are layered to allow the use of multiple poles; each layer is equivalent to one pole. Usually such a switch has a detent mechanism so it "clicks" from one active position to another rather than stalls in an intermediate position. Thus Automotive Rotary Switches provide greaterpole andthrow capabilities than simpler switches do.
Automotive Rotary Switch Waterproof were used as channel selectors on television receivers until the early 1970s, as range selectors on Rotary Switch For Automotive Parts, as band selectors on multi-band radios, etc.
Modern rotary switches use a "star wheel" mechanism to provide the switching positions, such as at every 30, 45, 60, or 90 degrees. Nylon cams are then mounted behind this mechanism and spring-loaded electrical contacts slide around these cams. 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. For example, if only four positions are required on a twelve position switch, the washer can be positioned so that only four switching positions can be selected when in use.
