mean00 / lnPowerSupply

Overengineered DC/DC power supply

lnPowerSupply

Introduction

This is a very overengineered desktop power supply. Small feature list :

• Powered by Lidl or Aldi battery back
• Current limiting (not very good)
• Large display (320x240)
• Large fonts

C++ vs Rust

The software comes in two flavors :

• C++
• Rust

You can switch to either one (un)commenting the SET(ENABLE_RUST True) in the top CmakeLists.txt

NB: The rust version contains bit of c++ (the lnArduino low level driver + the ina219 driver)

Electrical Detail

You can use pretty much any DC/DC converter as a core, you need to adjust R2 depending on the feedback voltage (see lnPowerSupply.pdf) Be careful to stay below ~ 24v else the INA219 will blow.

Formula is ~ R2>420*FB

• FB=1.25=> R2>500
• FB=0.8=> R2>360...

The overal design is made of 3 parts :

• The DC/DC converter board itself
• The DC/DC control board, controlled over i2C
• The main board with a STM32 or GD32 driving the screen

Why go to such a design ?

You need to have the control part close to the DC/DC You need to have the SPI screen AWAY from the control board

Small Youtube demo