Monday, April 09, 2012

Travel Gadget: USB Charging helper

Category: [Travel Gadget]

Long time since I have seen this blog! Recently I have been coming across some electronics which are charged by USB or it's smaller form factors. I only wish my point and shoot digital camera could also charge by USB to reclaim the space occupied by its charger in my luggage. But I have digressed...

I bought and then re-purposed this device:

The USB spec discusses four pins, one for grounding, one for 5 volts of power, and two data pins. The spec also mandates that charging devices should short the data pins for compliance. Many charging devices do not follow that spec and leave the data pins unshorted. This limits me from charging some devices unless they're plugged into a computer, which can complete the USB host/client discussion.

In order to future-proof myself from misc power sources and also to avoid occupying much space in my luggage, I found a USB extension cord. More accurately it is called a USB flexible adapter. The original purpose for it is to enable someone who couldn't position their USB device horizontally to bend the adapter and have it positioned vertically.

As you have read along, this was not my use case, so I did a little surgery to make it suit my needs. It was successful and now has an unexpected positive new use for me, which will be discussed in a later post.

  1. Soldering Iron (optional)
  2. Wire Cutter (optional)
  3. Hobby Knife
  4. Hot Glue (optional)
  5. Super Glue
  6. Small pliers (optional)
  7. Multimeter (optional for continuity testing)
  8. Electrical tape
  1. Using the hobby knife carefully cut the crevice on the edge of the plastic near the part that reads BELKIN
  2. Cut the other side (One side will be MUCH easier than the other)
  3. Remove the plastic outer casing
  4. Cut the wires which map out to the D+ and D- pins while leaving enough space for splicing or soldering.
  • You can use the multimeter for continuity testing if you're unsure. Alternatively, look at the device and see the four wires that go into the USB connector fixture. It's the middle two wires from that set of four. The fifth wire is connected to the outside of the USB connector fixture.
Continued below the picture.

  1. Strip enough wire to solder or splice
  2. Solder or splice these two wires on the side of the USB fixture together
  3. Cover with electrical tape and/or hot glue
  4. Cover the unconnected leads of the other side with electical tape individually
  5. Affix them to something somewhat stationary
  6. Test out the contraption is working as intended. Use something you don't care about in case you messed up and somehow connected a hot wire to an unintentional place.
  7. When satisfied, snap the fixture back together and add super glue to secure it
Now with this between my non compliant USB charging device and the USB cable attached to my electronic device I am able to guarantee a charge. This guarantee also does not use much space in my luggage. When I am no longer tired you will find out another great use case I was able to get out of it.

Final Result:


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