computer current

i want to power a computer from a 12V battery. so:

how much current does an average mother board need for both 12V and 5V? it's something like a pentium 1 or 2
Can i somehow use the one battery for both +12V and -12V (and +/-5V)

it is an older one so it just has the old AT power supply, what are all the connections needed? - there's +/-5V, +/- 12V, ground, and something else i don't know what it is.

i was going to just build some high power regulators to run it. is this the best idea?
I have already powered the CD rom drive and hard drive using 12V and 5V regulators.

Thanks for any help, i'm making a portable jukebox.

Josh.

The current requirements can be quite high, you really need a switchmode PSU - there are plenty of designs on the web for in-car MP3 players using computer boards. If you search on this board it's been discussed previously, and there's even a circuit posted.

A quick search found this - https://www.electro-tech-online.com/threads/how-a-transistor-works.4806/

To power something like a computer from a car battery will last no more than 5 hours. Since your running a pentium 2 i would think you need about 200 watts.

I would use something like an inverter to boost voltages upto 240/120v. Your monitor needs 240 volts remember!!

Ithink ti wod need 30 A and he cod use a LCD(it can run on 5 v)

pike said:

To power something like a computer from a car battery will last no more than 5 hours. Since your running a pentium 2 i would think you need about 200 watts.

I would use something like an inverter to boost voltages upto 240/120v. Your monitor needs 240 volts remember!!

Click to expand...

there a step up transformer in a CRT monitor for us 110 guys?

well i was going to use an LCD monitor which runs on 12V! but i'd like to use a switchmode step down power supply so that it's economical, coz it's running off a battery. so is there a schematic of a 12 to 5 volt switchmode at about 10-12 amps?

Thanks for help

Josh.