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 ...

[Paulo’s] garden lights are probably a bit more accurately automated than anyone else’s on the block, because they use latitude and longitude clock to decide when to flip the switch. [Ed Note from the ...