"Jackal24" wrote in message
...
I have a car adapter that powers my pda and gps receiver. The adapter is
generic and has no information on it that says what the allowable input
voltages are. Is there an easy way to determine if it allows a 24/28v
input?

/wry/ Sure, plug it in to the 28 volt connector. If it starts smoking and
fries the pda and gps, it wasn't meant for 28 volts /*wry*/

The only way I know for sure is to call the manufacturer of the adapter and
ask. That what I personally would do.



Also, is there an easy circuit to convert 24/28v to 12/14v for these kinds
of adapters?

Yes. A 7512 voltage regulator will handle the job quite nicely up to an
amp. THere are ways beyond that if you need more current, but not a subject
for a newsgroup. I believe Rat Shack still carries the 7512, and if not,
the LM317 is the adjustable version of a 1 amp regulator.

Jim