Hello all, I am creating an Arduino project using 120 electromagnets with three Arduino Megas. It was working fine when I tested each Arduino individually. Once I connect all of the electromagnets to the external power supply, it had smoke coming out. Ever since that, they are having problems. I am wondering if anyone knows what step did I do wrong and how to fix it.
So here is my set up:
I am connecting 40 electromagnets to each Arduino Mega and turn on pins one by one to see if they work.
Right now, the first Arduino works ok. Only two magnets are stayed on at all times not following the code. I think that two IRF540 are broken. However, when I tried to connect the Arduino to my computer, the port cannot be found.
When I plugged in the second Arduino Mega, it still has a burning smell. And the voltage would drop to 3.7V and 10A. Most of the magnets are still working but with weaker suction power. I tried to switch to a new Arduino but the voltage still drops.
And the third one works well but has a burning smell in 20 seconds after being turned on.
I don’t understand why are they acting so differently and weird. Please help me locate the problems and possibly solve them.