Making a USB charger cable
for a Palm Tungsten TX

Copyright 2008 by Stephen Vermeulen
Last updated: 2008 Oct 12
Digital Video

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The charger AC adapter for the North American Tungsten TX is not a universal 120-240V design, so on a recent trip one of ours got fried. On closer inspection it is marked as providing 5.2V DC at 500mA, which is what a USB connector can supply, so since I have a pile of unused USB cables (left overs from devices that have died or been replaced by better versions) I decided to make a short USB charging cable for the TX. This will allow it to be charged from a computer, or if one is not available, from an AC socket via one of those AC to USB power wall plugs that are commonly available these days.


  • one dead Palm Tungsten TX wall power block, marked output: 5.2VDC 500mA
  • one USB Type A to Type B plug cable
  • heat shrink tubing
  • solder


  1. cut the Palm-connector (along with some cable, say a foot) off the wall adapter, strip the outer insulation back an inch to reveal a red and black wire
  2. check that the red wire goes to the positive side of the Palm-connector(it did in my adapter)
  3. cut the USB cable to and keep the Type-A connector with some cable (again about a foot or so), strip the outer insulation back an inch
  4. the USB cable will have a braided wire shield which you can remove and under that may be a foil shield which also can be removed. This should reveal 4 cables, the two heavier gauge cables will be red and black (these are the power cables) and there are two data cables that are white and green. See this page for more details.
  5. Now trim off about 5mm (1/4 inch) of insulation from the red and black wires on both cables
  6. You can check the USB cable to make sure the red is the +5V wire by connecting it to a computer, just make sure you don't short the red and black wires.
  7. Before soldering things together, slip a bit (1/2 - 3/4 inch) of heat shrink cable over one of the red and black cables, once you have soldered the joints you can slide these pieces across the joints and shrink to cover them.
  8. As well, take about a 2 to 3 inch piece of larger heat shrink cable and slide it over the USB cable (which is probably thicker than the power adapter's cable); again, once the joint is complete you will slide this over the joint to cover the two red and black cables which are individually covered with heat shrink tubing. This outer covering will protect the whole joint and secure the unused USB data cable ends.
  9. now join the two red wires, and solder together. Then join the two black wires and solder together.
  10. slide the heat shrink tubes on the red and black wires over the solder joints and shrink them.
  11. slide the outer heat shrink tube over the whole joint and shrink it.
  12. test the cable for continuity.

A Rant

First I'd like to curse Palm for shipping a great organizer with a 120V-only wall adapter, it is one of the few such devices we own. Well, I guess that problem has been addressed!

Second I'd like to curse Palm for their repeated stupidity in both using custom USB cables for data sync and then not using them to charge with the USB power. The Tungsten T3 does allow for charging over USB, but only if you use the big bulky dock or a third party USB cable. The low-end Palm Zire models use standard USB cables for data sync but also do not charge over them.

Back to my product hacking page or Palm Pilot page.

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