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 ...
Designed for the electric power industry, the Series 24 and 31 latching switch relays (LSRs) are used to open or close and maintain up to 20 contacts and can be operated either manually or remotely.