Main Content

Supplino - DIY PSU

A simple PSU made with breakout boards and having a cool graphical display

Supplino is a Quick & Dirty PSU (Power Supply Unit) made with some widely available breakout boards, an Arduino Nano (or an Arduino Nano Every) and a graphical LCD.

Power output is given by a DC/DC buck converter based on the XL4016E1 IC with possibility to regulate the output voltage. Regarding the power input, we prefer feeding it through an external 20÷30V brick PSU such as the ones used for laptops or old printers: this solution is safe and cheap, but you can choose to use a larger enclosure and then include internally your own transformer+diode bridge+capacitors but with a lot of precautions. We used this project to recycle some old printers PSU that have an output voltage of 24V.

Arduino does not manage the buck converter module but only measures output voltage and current through a current sensor and then shows those values on a display. Power value is showed too. An additional analog gauge can be configured for showing voltage, current or power value giving some retro style to the graphics.

Power output on the banana socket is feed through a relay, so Arduino detaches the output power sensing an external pushbutton or on alarm events (short circuit/under voltage, over-load, over-voltage).

There is a secondary DC/DC buck converter module set to 5V for powering the logics, taking input from the same input of the adjustable module. Eventually you can port also this 5V on the panel (making adjustments to the provided enclosure).

We choosed this configuration since is cheap, simple and fully adaptable to other kinds of voltage converter designs, so the final user can choose whatever he want, also based on old-style linear voltage regulators such as the LM317 or LM338K. Anyway you must use the exact parts listed in the BOM if you want to use the provided enclosures you can 3D-print yourself.

We named it Supplino since we like a lot an italian snack typical of the roman cuisine, called Supplì and because is the contraption of “Supply” and “Arduino”.

The XH-M401 buck converter module
The XH-M401 module is based around the XL4016E1 buck converter IC. It can accept as input 4÷40V and gives an output 1.25÷36V. Manufacturer of those boards states a maximum output current of 5A that can be increased up to 8A by adding a fan, anyway we never used it for currents above 2A so we not tested it above 2A.

This module has a switch-potentiometer for turning on/off the module and adjust the output voltage. The output current on this specific module is fixed to the maximum allowable by the buck converter IC.

For using this module with enclosure we’ve designed and provided here you must remove the switch-potentiometer because we will use an external multi-turn potentiomer.”

Link to article