hello guys! i think i need your help again. So: the dc motor i am using is rated at 200watt. i did the wriing, exactly as Zabb suggested, and i used An IRL1404.
http://www.irf.com/product-info/datasheets/data/irl1404.pdf
i also used abig enough heat sink. but after 1 mintue of work, the outpout of the motor starts droping , and the heat sink is hot as the sun....
i talked about it with one friend that knows a bit more and he told me that , 20A is nowhere near anything that this mosfet can handle, and that it shouldent overheat that much. ghe suggested that :
1)the controller i am using (Arduino atmega128) does not produce High enough pulses, to compeltly saturate the Mosfet, resulting in ,it, working with some on-resistance
2)cause of the high capacitance of the gate, the Mosfet might be taking some more time to de-saturate
3) if that is the case , he suggested that the frequency of the pwm might be to high ? (i think arduino defults at 1khz) , and that maybe i should lower the 1kΩ Resistor, or build a drivind circuit...
what do you guys think??? how could i adress this problems?? thanks!