DIY Wall-Wart USB Power Supply

Reverend Jones from the Hacked Gadgets Forum has posted a creative way of making an old wall-wart (plug in power supply) into a useful USB power supply.

“Here is a quick and easy way to make an USB charger/power supply powered by the wall outlet. This can be used to charge/power a PSP, iPod or any other USB device.
First you need to acquire a regulated 5 vdc wallwart rated at 500ma or higher. The one I used is from an IoMega Zip drive. It has a switching regulator with an output of 5vdc @ 1amp.

Other parts needed:

1) 330 ohm 1/4 watt resister
1) 10k ohm 1/4 watt resister
1) 3mm LED (red, green or yellow)
1) USB-A jack, female ”

14 Comments


  1. Useful!
    I might have to make one.


  2. Now to make all your 5v techy goodnesses use USB


  3. Nice clean mod!







  4. this is my first time to do some inrush current research in USB power supply.So give me some basic
    information of USB power supply,please.


  5. in tha above photoes,there is no thermistor resistance component.
    i guess it is not a good USB power supply.


  6. Just out of curiosity, what are the two resistors and the LED for? I looked through the article and they’re never mentioned.


  7. The 330R resistor is the current-limiting resistor for the LED. The LED and resistor are wired across the supply as a power-on indicator. Not sure on the 10K resistor…


  8. Alan Parekh. I need more detail on how to wire the USB Power adapter. I know the negative wire goes to the chassis of the usb connector, but the power wire is attached to the resistors. which one goes the the usb and the LED. Thanks

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