Double Pole Double Throw (DPDT) Switch

What is a Double Pole Double Switch (DPDT) Switch?

A Double Pole Double Throw (DPDT) switch is a switch that has 2 inputs and 4 outputs; each input has 2 corresponding outputs that it can connect to.

Each of the terminals of a double pole double switch can either be in 1 of 2 positions. This makes the the double pole double throw switch a very versatile switch. With 2 inputs, it can connect to 4 different outputs. It can reroute a circuit into 2 different modes of operation.

A Double Pole Double Throw Switch is actually two single pole double throw (SPDT) switches.

Double Pole Double Throw Switch (DPDT) Circuit

Below is an example of a circuit which utilizes a double pole double throw switch.

You can see above how a double pole double throw switch can allow a circuit to be in 1 of 2 modes. When the DPDT switch is switched one way (flipped upward in the diagram), the lamp and buzzer are both on, while the LED and speaker are off. When the DPDT switch is switched the other way (flipped downward), the LED and the speaker are both on, while the lamp and buzzer are off.

This shows the dynamic 2-mode capacity that DPDT switches allow, allowing control of 4 different devices (with 2 operational modes).

Related Resources

Single Pole Single Throw (SPST) Switch

Single Pole Double Throw (SPDT) Switch

Double Pole Single Throw (DPST) Switch