USB Voltage and Current Tester!! (version 1)





Introduction: 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!

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.

Step 2: Assemble+TEST

Drill 3 holes into the Bay Cover.

Two on one side about 1/2 inch apart

One on the far side of the Bay Cover, across from the other two, preferably between them.

We are only using the RED (5v) and the BLACK (GND) wires for this.

Cut the BLACK wire and strip a length of it on both sides of your cut (just enough to solder).

Cut the RED wire and do the same.

Now, place the finishing nails (or whatever you are using) through the holes from the bottom of the Bay Cover.

Solder both ends of the BLACK wire to the solitary nail.

Solder each of the RED wires to ONE of the nails.


Step 3: Glue That Puppy!

Just in the case the wires get pulled or the nails come out, let's fill the "body" of the Bay Cover with with glue of your choice.

That bugger isn't going anywhere now!

Step 4: Almost Done!

Now that it's mostly together, it looks kinda boring...

Let's work on that!

Step 5: Looks

I added a piece of RED electrical tape to the side that has the pins for VOLTAGE. (just in case I am not the one using the unit)

And a label, I also hot glued a piece of BLUE foam to the bottom.

Step 6: Usage-Voltage

Ok, now that it's put together, here is the info on how to use it!

To check VOLTAGE, use the binder clip ACROSS the TWO pins that you attached the RED wires to (see why I put RED tape on them?)

Then place one of your MULTIMETER clips/hooks/whatever on one of the RED pins and on the BLACK pin.

In case you didn't know, make sure your testing leads are in the correct ports.

Step 7: Usage-Current

Set your MULTIMETER ports, and attach your leads to the TWO pins, doesn't matter what color goes to which one.

BTW, it doesn't matter if the USB devices are plugged in at any of these stages or not.

Have fun testing your PORTS and DEVICES!!!!



    • Science of Cooking

      Science of Cooking
    • Pocket-Sized Contest

      Pocket-Sized Contest
    • Spotless Contest

      Spotless Contest

    We have a be nice policy.
    Please be positive and constructive.




    I have Acer i5 laptop and all of my usb port are dead because of brownout I think the problem is in the board but when I plug a optical mouse the red light alive but no response in system my brother said the mother board of my laptop have damage like the resistors somthing like that, how can i fix the low voltage output in my laptop please help me I can't work because of this problem.

    Just make sure not to fill it with conductive glue!

    USB voltage and current test is truely not easy.Here is a perfect solution:
    The product will be laucned in June.
    You can buy it very easily on EBAY.
    Good luck!!!

    do you know how much current a ipod touch or iphone draws

    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.

    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.


    thats a pretty good idea, looking forwerd to the mini version

    If I get the time, it should be up sometime on FRIDAY! You WILL love it..... Just gotta figure out a few things.

    OK, got it all figured out, just assembling and painting today. I "should" be able to post it today.

    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.