McGyver Way: Power over USB

Travel is a hassle these days: airline on strike in Europe, long security lines at the airport, bumpy flight and long transfer to the hotel which is so tiny that the taxi driver missed it twice! Anyway, at least this time the reservation of the room *did* work. Arrived completely tired and with notebook batteries drained and empty. Unpacked the power adapter, ready to charge it up. Only to realize that the notebook power supply cable does not match the travel adapter plug! :-(:

Travel Power Adapter Mismatch

Travel Power Adapter Mismatch

So I have packed the 3-pin notebook power supply instead my usual travel 2-pin one 😦

It is late, there is no matching power adapter or cable at the reception. But I need to charge the batteries. In the old days I always travelled with a Swiss Army knife, but this is not easy any more because of air travel safety 😦 Things are sooooooo easy for a McGyver because he *always* a Swiss Army knife with him!

Hmm: A dirty trick would be to cut the ground pin on the power cable, but that’s hardly impossible with the right tools, sitting in a room at night-time. But what else can I do?

Checking all the material I have with me, the most useful stuff I have is:

  1. A pen
  2. Two small band aids
  3. A package of chewing gum
  4. A micro USB cable
  5. A USB cable extension cable
  6. Two small plastic bags
  7. Several Business cards
  8. A small cable binder
  9. A wish to get my batteries charged

❗ ❗ WARNING: DO NOT TRY THIS!!!!!! :! ❗

The idea is to build a power cord adapter using the USB cables. The hardest part was to cut the USB cables without a knife. The pen helped me to perforate the outer cable. With this I was able to remove the isolation and to combine all the wires of the cable:

Cut the USB Cables

Cut the USB Cables

USB cables are usually specified for 500 mA, and my notebook power supply rated for 1.2A. I’m using all wires of the USB cable, including the shielding, so things should be OK.

WARNING: Mains voltage (230V in this case) means danger and can create a deadly electric shock, or fire, or both! Don’t do this. Do NOT try this! Seriously! You have been warned!

I don’t share too many details, as I don’t want that someone stupid tries to replicate this. Be assured that I did all the precautions and safety handling possible, carefully isolating and wrapping things for good contacts and protection!

It's charging

It’s charging

Finally it is powering the notebook power supply :-). I carefully monitored the charging, always ready turn things off and to pull the plug. With the batteries were fully charged, I disassembled everything again. I had to sacrifice my two USB cables, but I have full batteries again.

But it would be so good if the world would have standardized on a single power connector….

Happy Powering πŸ™‚


7 thoughts on “McGyver Way: Power over USB

  1. Did you …. use each cable for a power line, then use the pen to poke each wire mass into each hole, then wrap each sheild around each plug prong, then hold them in place with the band aids, then put a folded business card between each prong for insulation, then use a cable tie to keep things in place, then put the plastic bag around the whole mess so that if there was a bunch of smoke it wouldn’t set off the fire alarm, and then hold your breath and turn your face away as you very carefully plugged it in?

    If so, that was a great idea (and I won’t tell anyone).

    If not, I am curious about how you accomplished it.


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