electronics made easy
PWM control of an electromagnet with Arduino.
Arduino's pin is protected with 4N35 optocoupler.
MOSFET is IRF520 (RDS(on) = 0.27Ohms ==> gets hot).
Inductance of electromagnet is unknown (home made)
R0 will be removed in a future design since it gets hot as well (5ohms and 2amps).