Wayne Paul wrote:
Marc,

I also believe the power line in the USB is 5V and your Garmin requires 12
V. So you need some kind of a voltage regulator to drop the voltage from 12
to 5 (12 will fry your PDA.)

If you're feeling handy with a soldering iron and want to save a little
cash, go out and buy the cable used to power an iPAQ from a car cigar
lighter socket. They are cheap and the plug on the cigar lighter end
contains a very small switch-mode 5v power supply. You can also find
iPAQ cable with 12v ans serial date lines in it, so you only need one
cable and plug on the iPAQ.

It may be a good idea to put the PSU in a metal box and add ferrite
suppressors to the cables connected to it because some switch mode PSUs
radiate RF like crazy.

I use exactly this setup, but the box is bigger: it also holds the
interconnect wiring to feed GPS data to my iPAQ, SDI C4 and EW logger as
well as distributing 12v to the GPS, logger and C4. All connections to
the box are D-9 connectors apart from 12v in, which is an XLR chassis
plug to match the glider's power cable. This way I can also plug a gel
cell directly into the interconnect box for bench testing at home.

The result is a neater setup behind the panel because there's just one
cable between the box and each instrument apart from the C4, which
requires a separate power cable.


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