I had some DC-to-DC converters and voltage displays laying around, so I thought I'd try making a simple power unit. It's really useful for me, since I can simply plug in a micro USB cable, adjust the voltage, and connect anything, without the individual parts flying around.

Specs

• Input: 2V-24V
• Output: 5V-28V @ max 2A

Parts

You need three types of parts, a DC-to-DC converter, a voltage display, and 2x 2-pin terminal blocks (or 1x 4-pin). Here are links to the items:

• DC-to-DC converter
• Voltage display
• Terminal blocks

Keep in mind that these parts can be obtained elsewhere and from different manufacturers, but the dimensions must be the same. The parts fit very tightly and the printed parts might need a bit of sanding.

Connections

Super simple: connect the converter inputs/outputs to the terminal blocks, and the voltage display to the outputs.

Note about the converter

When I initially tested the converters, they didn't work properly. After looking through tons of stuff I stumbled across a review on Amazon that had a solution. Two of the pins on the underside of the board have to be connected, this must have been overlooked by the manufacturer. I included a picture of the connected pins for reference. Note that your board might work fine, do this only if it doesn't work.

The converter can be powered through the micro USB port or with soldered connections. This design incorporates both options, although the USB port cannot handle as much input power as the soldered connections can. Input goes through two terminal block connections or USB, output goes through the other two terminal connections. It's up to you to decide how to wire it, but it's a good idea to label the inputs/outputs and polarity.