unpowered usb host idea (hack)

Derek Pressnall dpressnall at gmail.com
Mon Jan 22 19:11:16 CET 2007

I realize that the reason the usb host port is unpowered is because
the phone runs at something like 3.6 volt, and powered usb requires 5
volt, which would add the need for dc-dc converters.  So, I've got an
What about adding a power tap next to the usb port, running at the
phones native voltage?  This should only be a matter of adding an
additional connector (and possibly protection circuitry).  Then, an
adapter cable can be manufacured seperately that has a usb mini-A and
power tap connector on one end, and a full-sized usb-A on the other,
with the dc-dc circuit inbetween?  This way, it leaves the potential
for powered external devices without complicating the phones
circuitry.  Of course I realize that can't be included in the first
production run, but possibly an idea for the followon product.

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