Recommended · for some experience
DIY Buck Converter || How to step down DC voltage efficiently
Why people recommend it
GreatScott builds a DIY buck converter with an Arduino driving a MOSFET, cited as a clear way to understand how step-down switching converters work.
Watch for: The slow Arduino feedback loop may regulate poorly at light loads.
In their words
For step-up/step-down DC-DC converter theory look here, here and here.
Maximilian Gerhardt on arduino.stackexchange.com, Mar 2018. CC BY-SA.
I was following the circuitry by great Scott for the DIY buck converter here:.
Trex on electronics.stackexchange.com, Feb 2019. CC BY-SA.