Im designing a lighting unit for my reef tank with 150W of LED. There are two channels, one which runs on 12v2A and the other runs on 12v3A, there is also a separate power supply for the arduino controller and 4 cooling fans. I will be dimming the two channels using two IRF540 Mosfets controlled by the arduino. Now, the mosfet and the arduino need to have a common ground. Ive tested with one mosfet and found this to work properly. But I dont know if its okay to ground two mosfets, running on different power supplies, together. Im not from an electronics background, and this may seem trivial, but is it okay to just connect the two grounds of the two power supply into one ground line and just hook everything with that? via /r/DIY http://ift.tt/2v0FlA2
