USB PD multi-voltage trigger

I needed USB PD to barrel jack with multiple voltages.

This project was started when Deviant Ollam posted a video about using a USB PD trigger to barrel adapter with a barrel adapter kit instead of sorting through a bin of power bricks. The issue was that USB PD trigger only output 19V, which not all devices will tolerate.

Final

So I found this USB PD trigger module with solder jumpers for voltage and made a shitty enclosure for it. closeup of trigger module" style="max-width:400px;width:100% You short the three pads to make different voltages.

Voltage│Short pad
        A│B│C
     20│0│0│0
     15│1│0│0
     12│0│1│0
      9│1│1│0
      5│0│1│1

Prototype

Just threw it together, it worked fine: prototype

Enclosure

I got a friend to model something close to good enough in fusion 360, and then I edited in blender to adjust for tolerances. parts dimensions

My final STL

Assembly

The hardest part was soldering the tiny wires to the pads without shorting anything.

  1. put 30AWG wires on the trigger module
  2. glue the wires down (by the end I had found that superglue worked the best because hot glue left too much of a bump)
  3. put the dip switch and voltmeter and trigger module in the enclosure
  4. trim wires to length to reach the DIP switch
  5. strip wires
  6. solder wires wiring trigger to DIP switches
  7. put in wires for voltmeter wire in voltmeter
  8. Tune voltmeter so it's a bit above instead of a bit below (showing 8.9V for 9V is more annoying than showing 9.1V)
  9. Pot dip switch in epoxy or superglue or hot glue
  10. put in output wires (14AWG speaker wire was just what I had lying around) all wired in
  11. glue in display and dip swith with something fast curing (my first one had epoxy leak out the front and look bad)
  12. pot the back with epoxy potted back

Next Steps

I did monday evening when I was leaving tuesday afternoon for defcon, so it could be a lot better

If anyone wants to help improve this I'm happy to update this post with better stuff and credit you.

Parts