Hi,
I have been trying to control a 12 volt DC car wiper motor, with the load it it draws 2 amps.
I have written a program on a 12f683 using HPWM which works fine. The N channel mosfet (STP36NF06) is causing me a few problems. With this mosfet connected to the pic with a 330 ohm resistor in series with the pic and a 470K ohm resistor connected between the HPWM pic pin and ground the mosfet does as it should. I have also put a diode across the Drain and source (reverse biased) to limit the back emf of the motor. When the terminals connected to the motor are shorted out the thermal fuse (trip current 2.5A) cuts the power but the mosfet shorts out either across gate drain and source or just the gate and source. For test purposes I am running the motor from a 7 Amp hour battery when I short the thermal fuse with my meter reading the current it trips in about 2 seconds to mA's. Yet this still damages the mosfet when the short is tested on the circuit. The mosfet is rated at 30A and 60 volts, has any one had this sort of problem or knows of a way to over come this problem? any help would be much appreciated.
Nick
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