Simple Desktop Power Supply Hack

If you do small electronics projects and you're just beginning you probably do what I did for years to power your projects while working them which is to cut the business end off the the cord on a wall wart power adapter with the appropriate voltage. This works but keeping around a pile of plug-less adapters for project possibilities is kind of a pain. There's the ever common 9 volt and 12 volt adapters, but who has a 3 volt adapter to test battery driven projects or god forbid; a drawer full of spare batteries to blow through while working out your latest design? If you've reached the breaking point and started looking at desktop power supplies you have probably noticed the stupid high price on most desktop supplies designed for the job or maybe you've stumbled across the PC power supply DIY option. I've seen both and I neither wanted to spend a Benjamin on a supply nor wanted a monstrous PC power supply sitting on my desk all the time. I came up with a quick hack that makes for a nice, small, inexpensive desktop power supply.



Searching eBay like I usually do, I came across an adjustable power supply for tattoo machines of all things. I know exactly squat about tattoos but DC voltage is DC voltage and I would take a shot at using it since this thing costs maybe one third or less of what I was looking at elsewhere. At only twenty bucks if it blew chunks I could always post an "I hacked and failed" article right?

The first thing to note was the odd Y lead that comes off this thing, the business end that somehow attaches to a tattoo gun. Well, I said I was tired of cutting the business end off of DC power supplies, but one more won't hurt. Just cut it off, split the wire and solder on an alligator clip to each lead. Viola, ready for use.

The second hurtle was the odd little foot pedal you have to step on to run the tattoo gun. No need for pedal power so I disassembled the phono plug at the end of the pedal, cut the wires loose and soldered the two contacts together forever depressing a pedal that would be no more. Now the pedal has been reduced to an always-on plug, plug it back in and your power supply is now always-on.

This unit is very small, offers a nice range of DC voltage (1.5v to 16v) and can actually carry a pretty heavy load.  It even has a nice digital display of the voltage provided.  I hooked it up to my volt meter and the results were pretty darn accurate. I'm a happy camper. The leftover "pedal" is actually a pretty rugged and thin pressure plate that might well get used elsewhere.