I have a Current Sensing Relay System set up so that when the the amount of output current is below the desired amount. The relay turns off, waits 10 seconds, opens again and if the desired current is there it will stay on.
This is all working fine, I've used the exact same code for another Arduino with an electromechanical relay and it works as intended. It also works perfectly when the solid state version is plugged into my laptop however, the relay just stays off when its plugged into 12v or 5v from mains. If I plug a 12v in & power it from usb too it starts to works again.
Has anyone any ideas what that could be?
I've seen some simmilar posts saying that the grounding may be the issue but how would I think that if so, all grounds seem to be making good connection?
The circuit goes: solar panel> buck converter> Arduino current sense relay > inverter > monitor.
So maybe there's difficulty with common ground since there's a lack of mains in the rest of the circuit?