Use a switch mode or buck regulator. Input range at least from 10-14 volts, go
with fixed output 5V.

I build one last year using a chip and a few passives thrown on a circuit
board. Pretty easy. I'd have to dig in the ship, though, to get the Part
Number. Just Google away...many good options from Maxim, etc. Explore Digikey
and others to get all the parts together. Radio Shack won't suffice. Contact
me directly for more help.

Alternatively, you might find an evaluation kit or an off-the-shell solution
like from http://www.soarmn.com/cumulus/

I chose to build my own because I learned a new gizmo! Plus, many years ago I
learned which end of a soldering iron to hold...took a few tries ;-)

Jim Vincent
N483SZ
illspam