Albert Einstein He developed the general theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics).

The first integrated circuit invented by the engeneer Jack S. Kilby1 (1923-2005) contained only a few transistors. Texas Instruments.

Buck converter - FEEDBACK

Connect everything as in the schematic below, download and upload the next code to your Arduino and start moving the potentiometer. try different LOAD values and observe the otput on the oscilloscope.

Download the FEEDBACK code here:

Or copy the next code

/* This is an example code for a BUCK converter circuit made with arduino
 * I've used arduino NANO. We have to set the timer of the PWM on pin D3
 * The feedback is connected to A1 and we set the desired voltage with a
 * potnetiometer connected to A0.
 * Subscribe: http://www.youtube.com/c/electronoobs
 * webpage: http://www.electronoobs.com/eng_circuitos_tut10.php

int potentiometer = A0;
int feedback = A1;
int PWM = 3;
int pwm = 0;

void setup() {
  pinMode(potentiometer, INPUT);
  pinMode(feedback, INPUT);
  pinMode(PWM, OUTPUT);  
  TCCR2B = TCCR2B & B11111000 | B00000001;    // pin 3 and 11 PWM frequency of 31372.55 Hz

void loop() {  
  float voltage = analogRead(potentiometer);
  float output  = analogRead(feedback);

  if (voltage > output)
    pwm = pwm-1;
    pwm = constrain(pwm, 1, 254);

  if (voltage < output)
    pwm = pwm+1;
    pwm = constrain(pwm, 1, 254);