The portuguese forum is too inactive
I did reply to this very question there...
Hi, i want to make arduino control a 12v motor, but i want it to rotate left and right, i wanna make it with 2 5v relays. Here is the diagram, i draw it, and "relé" is relay in portuguese. Those arrows are diodes.direct link: http://s4.postimage.org/945iwwpox/001.pngSo, my question is, will it work and be safe?The relays are 5v so the High signal from arduino should turn it on right? But there's that reverse current on the relay, will those diodes protect the arduino from this? If don't, how should i make the circuit?Thanks, sorry if my english is bad :sThe portuguese forum is too inactive
The Arduino is only capable of sourcing 40ma per pin so that is why you need the transistor.