Whether they’re toggles or rockers, push-button or disconnect, switches are found in every 12V electrical system, doing everything from turning on lights to moderating critical systems. To understand the basics of electrical switches, you should first understand the internal circuitry. Then you can discern the difference between the different types of Auto switches.
SPST and DPDT
These acronyms represent the poles of the switch, and the number of poles (“S” for single, “D” for double). This is one of its most basic features. Poles are the number of circuits the switch can control, and throws represent the number of positions in which a switch can close a circuit. A single pole (SP) switch controls only one circuit. Similarly, Similarly, DP switch controls two circuit to connect two identical mechanical switches.
2 of the most common configurations are single pole single throw (SPST) and double pole double throw (DPDT). SPST is best known as the humble ‘on/off’ switch we use every day. The other one DPDT allows for the use of tandem circuits.