Gah, my typing is shocking tongiht.. 'Power Supply'.....

hey guys, has anyone done invertors or dc power supply units to power things like laptops, or conventional pc's in thier cars, or seen it done?

i know jaycar here in briz sell laptop power supply units that run from cig-lighter, and 12v-240 invertors and the like, but what i was wondering if anyone has seen/gone the way of cars existing 12v supply to convert that into a usable powerline for computer equipment, as this is mostly 12 or 5v anyway?

example, existing car 12v line, converted into something a regular atx motherbvoard would need?

i had a mate do something simlar a while back, but he had issues with delivering enuff power from his homebrew unit to power all the pc devices he wanted.

personlly, its seems the easy route to just get a proper inverter yer?

For conventional PCs, since from memory the ATX power supply also supplies negative voltages and voltage other than 5v and 12v, the best solution to my mind would be to use an inverter to convert 12v car power to 240v ATX power and run an ATX power supply.
I'd think you'd need a separate power line from your battery (like with a decent sound system) as a 400watt power supply is going to need a 33amp 12v supply to feed it - assuming zero conversion losses which is not going to happen. So you could be looking at a 45-50amp power requirement from your battery.

Stick to the laptop idea and convert DC to DC with filtering if you need a voltage other than 12v or just make sure you have plenty of filtering if your laptop uses the straight 12v.

The problem with car power supplies it that the voltage isn't constant, particularly if you've got a stereo pumping. You can buy DC power supplies dedicated for use in car, but they're fairly expensive.

Check out somewhere like this (http://www.mp3car.com/store/index.php?cPath=21) for DC-DC power supplies.

cool, thx guys.

ive been tinkering with the idea of a pc motherboard, booting from a 1gb usb stick, with a bootable os onit, rigged to play mp3/etc files from a other 1gb usb stick.

mostly as a theory to see if a mobo power only (no hdd or cdrom/etc) experiment would work moderately well for a sizable semi-permanant hardware mp3 player.

sure ive got a 2g portable mp3player unit that i can jack into my head deck for the same result, and also my headeck that allready supprorts mp3 discs, but ive got jack with scratched cds now, and going to come up with a nice hardware (solid state) music player.

Cheers fro the info!

Dave.

You can buy purpose built ATX power supplies that run from 12v DC.

here are a couple

http://www.powerstream.com/mini-itx.htm

http://cgi.ebay.com/M2-ATX-Car-PC-160W-DC-DC-Power-Supply-for-Mini-ITX_W0QQitemZ140011763175QQihZ004QQcategoryZ3670QQ ssPageNameZWDVWQQrdZ1QQcmdZViewItem

If you search on ebay in the US for "car atx power supply" you will find heaps

cheers dude!

Xwhiskey,

If you need any help with CarPC sort of stuff, I am currently doing what you have described.

I am setting up a M2-ATX power supply to run a VIA EPIA SP13000 1.3G MB. I will be booting XP off a 1Gb USB Flash drive.

There are a few software tricks to setting up a stable OS on flash drives... Flash drives die after about 100000 writes. Do a search on mp3car for EWF (Enhanced Write Filter) by sflorito.... He has done a lot of work on this. Also check out http://www.911cd.net/forums//index.php?showtopic=14181

for some good points on USB windows booting.

PM me if you want to chat about anything CarPC related.

Well i had my Toshiba Tecra laptop setup in the car, it depends if you want to be able to remove it or not lol. As i had my car power connect straight through and bi-passing the battery (with a fuse and diode of course), the laptop was hidden under the passengers seat (making use of the rails that the tidy under seat tray is on).

Before that i was using a 100watt modified sine wave inverter (if you can afford it for pure sine wave, much cleaner and more reliable power source) make sure the inverter has a higher continuous wattage rating than the power device, i have seen too many ppl burning out their inverters by doing this, any other help give me a yell

Just a quick aside here - for computers, you really can use any old inverter, sine wave or not, for the simple reason that they use switchmode powersupplies. They rectify the mains voltage into DC, and switch it at high frequency.

The only place you need sinewave is for motors and magnetic transformers (ie. iron core 50Hz) as they get hotter with the flat DC peaks of modified squarewave.

Trust me, I build power supplies as a hobby (amongst other things)

Cheers
Heath Young

top stuff!

thats some top info guys, cheers!

barty, well, atm i have a old 300mhz atx board here, ex ibm midi case, amd k6-ii, 256mb ram and am testing a bootable player os, once im happy with the cfg, i was gonna make it readonly, and have anything temporary running of a 2nd usb drive, that is pnp, as a data drive, playfiles, etc, so if it dies, doesnt really matter, plus the whole thing would just be iso'd as needed to re-image. atm, 1gb usb sticks are down to $30's around here, so its almost larfable lol.

even a sd card reader with swap n run dual card slots to boot from, and run content from.

atm, im building the protoype os on a virtual pc, and so far, its cominfg along, the hard part will be to get, afaik, power to the mobo that stable/filtered/spike safe/etc.

as my boot space is used by my wonderful twins pram, im looking at if the mobo will mount either under the driverseat, or, in the spare wheel well, or up against the rear boot wall.

even if the usb system disk becomes an issue, i have more than enuff spares here to run a ide/scsi disk as a system drive, but, that would be interesting from driving vibrations soon distroying the disks.

be pretty rad to slide a sd card full of tunes into the reader in the center arm console :-) having said that, ive seen a panasonic headdeck with sdcard slots.. maybe ill save myself the trouble and get one lol.. but thats not fun is it :)

xwhiskey,

I understand the need to carry baby gear in the boot... Hence the reason I recently bought a TL Magna.

As far as mounting the computer, I am fabricating a fixed 7" touchscreen into the double DIN spot in the dash, and my mobo and other computer gear will be mounted behind the screen in the radio location.