Battery Powered Power Supply
Battery PSU
2021
This was just a quick project I ended up doing because I needed a portable for projects where I couldn't usually bring my large lab bench power supply. This is a single CR18650 battery powered power supply, with a common boost converter module.
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As shown in the schematic, I originally was planning to use a LM2621 boost converter IC, but I ended up using a module because I already had it on hand and I needed this done relatively quickly. This is also why I designed and 3D printed my own custom case for this PSU and used all parts I had on hand.
The Arduino Nano controls the display, measures the voltage and allows for this to be programmable. There is a series pass transistor on the output of this, which allows the user to cut the PSU voltage or set their own frequency should that be needed (which is the second knob). I added a USB connector as well, because those always come in handy.
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The Arduino Nano is able to measure the voltage surprisingly accurately, given its' 8 bit ADC without an external voltage reference. The output noise was relatively low too, even so with how improper I was measuring it.