Subject: Running PCs on 12v

From: "Cini, Richard" <[email-masked]>
Date: Fri May 16 11:40:43 2003

Hello, all:

	This is a bit OT (because of the PC being used) but I believe that
the application of the solution is timeless :-)

	Anyway, I want to run a "book" PC on 12v while I'm outside using the
telescope (the PC will run the CCD camera setup). I gave some thought to
simply using an AC inverter, but converting 12v to 120v AC and then back to
PC power supply voltages seemed horribly inefficient.

	The power supply is rated 12v/5.5a and 5v/1a. It's an NLX-type
motherboard, so the 12v is converted to 5v for various peripherals at the
point of need. The 5v from the power supply is to support system standby
mode only.

	I went hunting for DC-input PC-form-factor supplies but they're
upwards of $200. I thought about directly connecting the battery to the PC
and using a small DC-DC converter for the 5v, but the battery voltage isn't
really 12v (it's more like 13.8v) so a regulator would be necessary.

	Any thoughts as to a simple, low-cost yet efficient solution?

Rich

---

From: David Woyciesjes <[email-masked]>
Date: Fri May 16 12:37:00 2003

>         Any thoughts as to a simple, low-cost yet efficient solution?

	Have you looked around http://www.mp3car.com? A site for putting PCs in
your car, as a music source. Here's some DC-DC converters you could
buy...
http://www.mp3car.com/hardwarecats.asp?Type=H&Cat=P
	I vaguely remember seeing somewhere on that site a couple different
plans for building your own supply...

--
---   Dave Woyciesjes
---   ICQ# 905818

---

From: Joe <[email-masked]>
Date: Fri May 16 12:56:06 2003

Rich,

   Any chance of using 48VDC? There's plenty of surplus industrial PCs (and
PSUs) that run off of that.  I've often wondered if you couldn't run a PC
directly off of 12VDC (with a regulator to drop one line to 5VDC). 

     Joe