Creating Power Supply for Computer in Car Environment

[jschen]

I know they sell these type of units for the car environment. I have decided to try DIY project on this and need some advise. What I want to do is build a power supply for a computer. I understand that when the car is off the voltage comes from the battery (12V) and when the car is on the volts jump up to 13-14 volts. I can't remember what all the rail voltages a Motherboard needs (I need to look it up) but how would one keep the voltages stable or working voltage for a computer? Especially for an audio system that will cause voltage drops and such?

 

[martin88]

I did a quick search on google and found this link its not for a pc its for audio but it has lots of background info in it hope it helps

http://sound.westhost.com/project89.htm

And keep us posted on any progress you make

 

[DigitalJunkie]

I got bored once,and decided to make a 12V input PC supply,I slapped it together in a day,and it's nothing fancy...but,it does work..

http://www.users.qwest.net/~ptaylor/Electronics/DC-PCsupply/12Vdc_PC_power_supply.html

Just a couple simple linear (inefficient) regulators.. with a small dc-dc converter for the -V rails. This is for an AT motherboard.For ATX,you just need to add a +3.3V regulator,and a constant source of +5V(standby).

 

[jschen]

Thanks for the help so far. This project probably won't be started for quite some time but getting the background info so when I get started it won't be so hard.

 

[dangus]

The forums at http://www.mp3car.com are about the best place for in-car computer information.

What kind of motherboard are you planning to use? There are very compact industrial PC boards that only require 5 volts; Pentium-class boards can be had for less than $100 on Ebay, and are fast enough for MP3 playback.

I'm going to use a switching regulator to get +5V and use a laptop drive which doesn't need 12V. Maybe add a DC-DC converter for +/-12V to run the audio circuits on the motherboard for better sound quality.