January 20th, 2022—
Working with electronics requires access to stable power in a variety of voltages. Some components require 3.3V and others require 5V. Still others need 9V or 12V — there are many possibilities. You could keep a variety of wall warts on hand, but a variable benchtop power supply is a more convenient option. Supplino is one choice and this guide from Giovanni Bernardo and Paolo Loberto will walk you through how to build one.
Supplino can accept anything from 4 to 40 volts and can output anything from 1.25 to 36 volts, with a maximum of 5A. An XH-M401 module with an XL4016E1 DC-DC buck converter handles the voltage regulation. Technically, you could use that alone to power your components. But the addition of an Arduino Nano board (or Nano Every) makes the experience far friendlier. It monitors the power supply output and drives a 1.8″ 128×160 TFT LCD screen, which displays the present voltage, amperage, and wattage.
The Arduino receives power from a second 5V buck converter. It uses a relay to control power going to the primary buck converter. A relocated potentiometer controls the voltage. Two banana plug socket make it easy to attach alligator clips or whatever other leads your project requires. You can wrap up all of these components in a tidy and attractive 3D-printed enclosure, which is compact and fits on any desktop. You have many options for the input power, but a laptop power supply is a good choice.
More details on the Supplino can be found in its post here.