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 ...

Aside from the Arduino UNO microcontroller, LDR, and the bulb itself, the hardware for this setup is pretty minimal: a relay for the bulb, a resistor for the LDR, and some wires to connect ...

[SaltyPuglord] needed a solid state relay for a project. We’d have just bought one, but he decided to design his own in LTSpice.Along the way he made the video below, which is pretty informative ...