Switching power for PC in cars

[Paul Beam]

>Another company makes a 4" x 4" x 0.5" power supply that takes in
>9 to 35 V DC and feeds out 5V (and optionally +12V, -12V, -5V still
>in the same volume), these are rather expensive though and I pay

Check out Marlin P Jones, http://www.mpja.com.  A 5V DC-DC converter with
9-40 VDC input is 5.95 (7819-PS) and a +-12VDC module is 6.95 (4493-PS).
The 5V unit is rated at 3A and the +-12 is rated at 1A.  You might want to
put some diode protection on the input to protect against bad spikes.  

Put a couple of these modules together and then make a cable to run to your
PC components.  Most MB's require an external "power good" signal.

I haven't been paying much attention to the original thread, but just
thought I would mention there are some inexpensive alternatives for DC-DC
conversion.

R Paul Beam
Computer Systems Engineer
Johnson Bible College
7900 Johnson Drive
Knoxville, TN 37998
(423) 573-4517
(423) 579-2337 fax