hello
New to arduino and from a not technical background.
Assembled a buck converter as per the wiring diagram but due to some reason not able to get output above 1-2 volts.
IRFZ44N mosfet
12V lead acid battery as power supply for buck converter
5V supply for arduino, ground of lead-acid connected to the arduino.
would be extremely thankful if someone can guide me in the right direction.
/for testing purpose with manual PWM cycle
#define pwmpin 9
#define vdpin A1
#define potpin A0
int Vdread = 0; //voltage divider raw reading
int Potread = 0; //potentiometer raw reading
float Volt = 0.00;
void setup() {
// put your setup code here, to run once:
TCCR1B = TCCR1B & 0b11111000 | 0x01; //increase PWM freq to 31KHz , timer 1 pin D9
pinMode(vdpin, INPUT); // voltage divider read
pinMode(pwmpin, OUTPUT); // PWM mosfet gate
pinMode(potpin, INPUT); //pot read
Serial.begin(115200);
}
void loop() {
// put your main code here, to run repeatedly:
Vdread = analogRead(vdpin); //raw reading of voltage divider
Potread = analogRead(potpin) / 4;
// Volt = (5.00 / 1024.00) * Vdread * 10.9;
// averaging 10 readings of voltage divider
int i = 0;
float sum = 0;
while (i < 11) {
sum += (5.00 / 1024.00) * Vdread * 10.9;
i++;
delay(10);
}
Volt = sum / 10;
// maping PWM duty cycle with potentiometer value
int pwmcycle;
// Potread = 128;
pwmcycle = map(Potread, 0, 255, 0, 100);
analogWrite (pwmpin , Potread);
Serial.println("output Volts " + String(Volt));
Serial.println("PWMreading =" + String(pwmcycle) + "%");
Serial.println("pot reading " + String(Potread));
//resetting variables
i = 0;
sum = 0;
delay(500); // Delay a little bit to improve simulation performance (0.5 sec)
}
You're driving an N-Channel MOSFET on the "High Side", that is switching 12V, using 5V on the Gate. You're getting lucky with Gate Threshold on that one. To do this properly, you need to drive the Gate at a full 12V, and for that, you need another transistor. Perhaps someone else will chime in with that -- or, tomorrow I'll do an update.
