SPST and DPDT Switches
There are four common switch types, today EPCB will go over two of them-- SPST switch and DPDT switch.
Single Pole Single Throw Switch: A single pole single throw or SPST switch is a switch that only has a single input and just connects to one output. This means it only has one input terminal and only one output terminal. It serves in circuits as on-off switches. When the switch is closed, the circuit is on. When the switch is open, the circuit is off.
Double Pole Double Throw Switch: A double pole double throw or DPDT switch has 2 inputs and 4 outputs. Each input has 2 corresponding outputs for it to connect to, and each terminal of a double pole double switch can either be in 1 of 2 positions. This makes the DPDT switch a very versatile switch. With 2 inputs, it can connect to 4 different outputs, reroute a circuit into 2 different modes of operation, and allow the control of 4 different devices. Actually, a double pole single switch equals to two single pole double switches.