On Sep 14, 12:28*pm, Martin Gregorie
wrote:
On Mon, 14 Sep 2009 11:38:59 -0700, jb92563 wrote:
Thats great, but WHICH one?

Do you have a link for that charger?

I bought an cigar lighter charger off eBay for my iPAQ 3630 when I bought
it, back in 2004. This charger delivers 1.4A at 5v and contains a tiny
switch-mode power supply, which I installed in the instrument
interconnect box I built and fitted behind the panel. The iPAQ never did
get installed in a glider, but now I run my Binatone PNA off the iPAQ
power supply. Works perfectly.

Bottom line: if one of these power supplies can power/charge a device
through its USB port then it can power/charge ANY OTHER device that can
be charged via a USB port: the USB 2.0 port specification says that the
socket must be able to supply up to 800 mA at 5v, so it figures that any
USB connected device must be able to be charged from such a port and/or
to be powered from it.

The only problem is that there are three USB connection types (the PC
size used on memory sticks and the two slightly different mini-USB sizes)
but that's easy to solve by using device specific cables with a common
connector at the USB end. That could even be a PC style USB socket -
Maplin (in the UK) sell USB sockets so you should be able to get them
from Radio Shack/Dick Smith/etc in other countries.

The switch-mode power supplies are readily available and cheap on eBay -
and many have a PC-style USB socket, so you can connect your device with
cable that came with it.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

That is *not* the only problem. This is a case where the devil is in
the details. Various (usually pull-up resistors) signaling schemes or
funky wiring are used by different manufactures to indicate charger
functionality or request higher current etc. As has been discussed
here the iPAQ 310 has some compatibility issues, there can be similar
issues with the iPhone, and so on.

Darryl