Xref: utzoo rec.ham-radio:22117 rec.ham-radio.packet:4131 sci.electronics:12960 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!sdd.hp.com!elroy.jpl.nasa.gov!peregrine!ccicpg!cci632!cb From: cb@cci632.UUCP (Just another hired gun (n2hkd)) Newsgroups: rec.ham-radio,rec.ham-radio.packet,sci.electronics Subject: Re: Running a PC on 12V Message-ID: <38706@cci632.UUCP> Date: 17 Jul 90 17:46:17 GMT References: <31677@cup.portal.com> Reply-To: cb@cci632.UUCP (Just another hired gun (n2hkd)) Distribution: na Organization: Ring Ring... The number is Lines: 35 In article <31677@cup.portal.com> dbell@cup.portal.com (David J Bell) writes: >Doug, you should have very little trouble, as far as I can see... > >The drive motors operate off 12V (the car is a little hot for that, but >it really *shouldn't* be a problem), and the electronics requires both >+5 and -5 volts. The plus 5 you can get with one or two regulators; you >should probably allow for as much as 5 Amps - maybe run the drives off >one LM117 and the mother board off another... The only sticky one is >the negative 5V. There are standard circuits in the applications notes >for low power inverters. The -5 only needs 100 milliamps or so. I suppose >you would also need -12 for RS-232, too; maybe you don't need that >in the car? > >Dave dbell@cup.portal.com I wanted to add a few things.... 1) the rs232 drivers can be replaced with MAX232 chips which only require 5 volts (instead of the 1488/1489 combo). 2) Many of the 12" monchrome monitors run off of 12/15 VOlts 3) You should still regulate the drive voltage 12V or you might have soem problems. 4) the -5 at 100 mills can be synthesized using cheap DC to DC converters (off the shelf). 5) I would suggest an auto shut down if the working voltage execedes the IC specs (ie4.75V ) because of data integrety problems. Maybe other than the monitor supply a drop in car to PC power supply could be built using the existing PS casing, Good news for Packet Radio, portable One... . -- email: cb@cci632 or !rochester!kodak!n2hkd!curtis Curtis Braun, N2HKD, Computronics, PO Box 1002 Fairport NY, 14450