SPST, SPDT, DPST, and DPDT Explained - Littelfuse What do SPST, SPDT, DPST, and DPDT mean? SP and DP refer to single pole and double pole, ST and DT refer to single throw and double throw. Pole refers to the number of circuits controlled by the switch: SP switches control only one electrical circuit. DP switches control two independent circuits (and act like two identical switches that are mechanically linked). 6 Pin Dpdt Switch Wiring Diagram | Free Wiring Diagram 6 Pin Dpdt Switch Wiring Diagram - Collections Of Dpdt Relay Wiring Diagram Fresh Dpdt Switch Wiring Diagram Guitar. Spdt Rocker Switch Wiring Diagram Explore Schematic Wiring Diagram •. Wiring A Spdt Rocker Switch Wire Center •. Dpdt Switch Wiring Diagram Guitar New Dpdt Switch Wiring Diagram. SPDT Relay DPDT Relay - Theorycircuit Relay is a electro-mechanical switch used to control high power application through low power signal electronic circuits, for an example a simple timer circuit working under 5V DC bias can not control high voltage light bulb, by introducing Relay component we can easily control light bulb.