I have a dumb question, maybe.
I am trying to drive an high current motor (14V,12A) with an mosfet H-bridge and an arduino (Yes i'm such a newbie using arduinoes tsk tsk). I have just roasted two arduinos in a row (CPU getting very hot, and unable to pull digitalpins low (1,8V ish)
The N-channel mosfet is connected directly between the digital pins of the arduino to the gate of the mosfet, and the P-channel is driven through an NPN transistor (pulling to ground when turned on) and a pull up resistor. The mosfet bridge is working fine, when i try to control it "manually" with 5v supply, but the arduino keeps getting roasted.
I am suspecting some kind of surge (over 5 volts? or under 0?) when turning the mosfets off, due to the capacitance of the gate, but i don't know, and a google search gives me 10 different answer. Some suggest 10k resistors to "isolate" the arduino digitalpins from the gate, but this will result in the arduino being unable to drive the mosfet with PWM right?
I am thinking attaching zener diodes to clamp the voltage to 5.1 volts, would that work?
I have just purchased my first oscilloscope, but it has yet to arrive, but maybe you guys would have a clue about this without a recording on a scope?
If neccessary, i can find a circuit diagram, right now it is just on my other computer which i can't get to right now.