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 ...

When everything’s plugged in, this is how your Arduino, motion sensor, and power relay should look. Jeremy S. Cook Plug the male-to-female jumper wires into the motion sensor pins.

For one, the sound doesn’t directly control the solid state relay used in the fan controller. When the microphone equipped Arduino detects enough noise, it will start a timer that keeps the fan ...