Picture of USB Voltage and Current Tester!! (version 1)

Since it's sometimes necessary to check your USB ports for voltage or if you are curious on what kind of Current draw your devices might be pulling, it would be great to have something to check these.

Now you can.

Instead of just hacking apart USB cables and checking these readings with a Multimeter or one of the Pen Drive style voltage checkers, this instructable will give you a tool that is painless to use.

Moving onward.....


Step 1: Parts!

Picture of Parts!
The pics for this step did NOT turn out.
What you need:

Soldering Iron & solder (duh)
Epoxy, aquarium sealant or hit glue (optional)
1 PC Bay Cover any size will do
3 finishing nails or similar items to make into "posts"
1 USB Extender cable, or pieces from other projects ;)
1 Binder or Bankers Clip shown below. (unpainted)

It might not be a bad idea to coat the handles of the clip with a rubber coating, something along the lines of PLASTIDIP.
AJMansfield2 years ago
Just make sure not to fill it with conductive glue!
inhaos4 years ago
USB voltage and current test is truely not easy.Here is a perfect solution:http://www.inhaos.com/product_info.php?products_id=28
The product will be laucned in June.
You can buy it very easily on EBAY.
Good luck!!!
mattccc5 years ago
do you know how much current a ipod touch or iphone draws
Koil_16 years ago
Actually you would need something plugged into it to test the amperage draw. And just a thought, it might be pretty easy to get a small switch to replace the bankers clip. You could also cut the lip of a bay cover and glue that to the back just for a better aesthetic appeal. Over all I would have to say this is a pretty great idea and I'm definitely going to build something simular. Thanks for the Instuctable.
gmgfarrand (author)  Koil_16 years ago
Already got a switch integrated.... It's small now. About the size of a small to medium FLASH DRIVE. I'll try to get it all up on the site this weekend, or at the latest MONDAY morning.
kraM6 years ago
thats a pretty good idea, looking forwerd to the mini version
gmgfarrand (author)  kraM6 years ago
If I get the time, it should be up sometime on FRIDAY! You WILL love it..... Just gotta figure out a few things.
gmgfarrand (author)  gmgfarrand6 years ago
OK, got it all figured out, just assembling and painting today. I "should" be able to post it today.
nubie6 years ago
This is pretty cool. My take is that you can get Digital Multi-Meters from Harbor Freight for $3 apiece, so you could have a meter with built in USB lead from Dollar Tree. Project Cost: $4. :) (or you could splurge on dual DMMs and pay $7 to get voltage and current measurements) Awesome.
gmgfarrand (author)  nubie6 years ago
nubie, Thnx.. I have been thinking your suggestion over, and I have a few more ideas that make the product smaller and still keep it simple. I'll make them and post when I get some more USB connectors in..
Chiana_Rei6 years ago
I like this, now if I could add in a lcd and mode selector, to view voltage and other such info, that would be even cooler, of course so would a million dollars.
gmgfarrand (author)  Chiana_Rei6 years ago
Agreed, but then it wouldn't be as simple...
jakdedert6 years ago
I think this is a good idea, but some potential for shorting your USB port exists. Perhaps you could recess the test points and use a SPDT switch to break the line for the current measurement. I don't think it would be all that much more difficult to build, and would be more compact. For example, a scrap of pcb could be glued inside the housing, with holes drilled for access...or for a more robust device, a simple pcb could be etched with three pads for test purposes and solder pads for the switch.
gmgfarrand (author)  jakdedert6 years ago
Thought about that, but with parts on hand, I came up with this current build. Plus, I wanted something I could clip on to, not have to hold probes against solder points, I tried that with an older revision, didn't like it. I thought about making something the size of a standard flash drive. I'm looking for parts as we speak.
mrmath6 years ago
Suggestion: Step 2a-Test to make sure all connections are good. Now's the time to fix a bad connection, not AFTER it's been epoxied to death.
gmgfarrand (author)  mrmath6 years ago
Good point, I'll make a common sense note to it! My 1st revision, had a bad connection that I didn't find until I used a whole tube of epoxy on it.
PKM gmgfarrand6 years ago
Second suggestion- instead of epoxy, melt a wax candle into the space. You can remelt it to remove it (might not be pretty, but it can be done) and I'm pretty sure it's cheaper than a whole tube of epoxy. Smells better, too. It's not quite as strong, but if it's only meant to stop short circuits or connections working loose it will do fine.
gmgfarrand (author)  PKM6 years ago
That's why I also mentioned using Aquarium Sealant or Hot-Glue, just in case future modification was wanted/needed. But, since if I wanted to change, I'd just make a new version anyway, I went with the permanent option. :)
lasertech6 years ago
Another fine project!!! I WANT!!!!
gmgfarrand (author)  lasertech6 years ago