I am currently working out the electronics side of an automated drinks dispenser. It utilises 3x 12V air pumps which I intended to power using relays. However I am very new to this and am not sure the best way to go about supplying power to 3 separate relays. Is there a convenient way to supply the power to all 3 relays (and the arduino itself if at all possible) without having 4 power sources?
To clarify, all of the 12V outputs need to be individually controllable so couldn't run from a single relay (unless there's a way I'm missing).
I say: use the 5 volt module. Else 12 volt is needed to make the relay switch. I've got both versions and I've just been testing them.... The 12 volt relay doesn't switch powered by 5 volt. Powering with 12 volt forces the controller to sink 12 volts or supply 12 volts.