Hi!
I want to control 12V solenoid lock using Arduino. I have 18V power supply(2x 9V batteries) and 5V relay.
Could you give me some tips how to do it? What resistor should I use? How to connect it all together?
I would be very thankful for any instructions or useful links.
Have a look at this:- https://maker.pro/arduino/projects/driving-a-relay-with-an-arduino