Building relays doesn’t have to be complicated. Using the right tools and terminals, you can build your own, ... Wiring Diagram. Terminal 86 = 12V trigger. Terminal 85 = Ground trigger.

It has 2 terminals and 4 connectors and you can look at the DPDT relay as the equivalent of 2 Single Pole Double Throw SPDT relays. DPDT relay applications 1. Change motor direction with DPDT relay.

In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board, one 1K and one 10K resistors, 1 BC547 transistor, one 6V or 12V relay, one 1N4007 diode and a 12V fan ...