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 ...

In his video guide, [Ben] shows us exactly how to fit a standard solid state relay into a regular outlet box, and easily control it with an Arduino Uno.