I am building the most efficient electric vehicle in the world. Please check the website in the link below. Hope the car is cheap so everyone can afford it. So I am designing and manufacturing my own cheap motor controller. My design is to use about 10 mosfet PWM controlled by Arduino to effectively control the speed of the car\'s 10 to 20 horsepower motor. The first part I tested has two MOSFETs on the same radiator. I was able to test up to 20 am p and the mosfet was only heated to 47C. If I raise the voltage to 48 V at 20 a, I can control 1. 3HP. This controller is perfect for large electric bikes or small electric motorcycles with parts priced at just around $10. Part list controller ( I used Arduino Mega but you can use timer switch or other micro devicecontroller)2 Mosfets (I used N- Road 60 V 30 amp qfp30n06l)Diodes (I used 4 1N5404)Head sink ( I use a large fin aluminum radiator)Computer fan (I used a 12V . 16A PC fan)Wire ( I used 18g, but 16 or 14 would be better for high amps, 22g for signals) BusbarFirst I soldered the wire to the Mosfet lead. I carefully separated them so that I had room for welding. On the gate pin I welded a 22g wire. I welded 18g of wires on the drain and the electric source. I put the Heat Shrink tube on any exposed part all the way to the Mosfet. I then connected the gate, source and drain of the two MOSFETs. I connected them on the bus. I connected a 22g wire to the drain on the bus. The door and drain pipe are attached to the breadboard. The 1 k resistor is used as a drop down resistor to discharge the gate when I have no power on. The gate is then connected to the digital pin 13 on the Arduino. The drain is connected to the Arduino GND pin. I then connect the potentiometer to the Arduino to control the speed and the LCD screen (optional). After applying some thermal paste to the back of the radiator, I fixed the mosfet bolts to the radiator. I use Arduino digital pin 13 because it does PWM at a voltage of about 1,000 hz. The sound of most Motors is annoying, but the frequency can change if you want. This program is very simple. Just enter a variable from the analog pin of the measuring pan. This value is then used to change the PWM duty cycle. Here is a small example of the program. The pot is covered by Arduinos army. The wiper on the Arduino drops the voltage between 0 and 5 when rotating. The analog reading function accepts voltage drop. We used this in the AnalogWrite function that created the PWM pulse. Int PWM = 13 AnalogRead (Pot); AnalogWrite(PWM, Pot/4); I installed a thermometer on one of the mosfet, tested many different currents and monitored the temperature. I can run the 17A long enough and the temperature is stable at 47C. Maximum current is over 20. I don\'t have a large motor, so I use 4 12 v motors and 4 bulbs as the load. When I get a bigger motor and make a bigger battery pack, I start testing a bigger controller of 10 to 20 hp. I tested my controller with a homemade lithium ion battery. I use 8 units in parallel and use up to 5 groups of 20 v in a row using 40 units. When I tested it in about 20 minutes, I noticed that my battery became very hot and the voltage dropped a lot.
