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 ...

This is a where a Power Mosfet comes in. With the help of the Power Mosfet, we can use the low voltage output from the Arduino ports to control high voltage/current loads -the popular “12V LED strips” ...