hi........can anyone help me!!!. im trying to fix my PC in my car, i need a 12VDC-DC ATX powersupply which can produce +12v,-12v,+5v,-5V,+3.3v,gnd......i just need a circuit diagram and PCB design.........:|
Much, much easier and cost effective, will be to get an off-the-shelf 350W 12V-240V inverter and use a standard PC SMPS with all these voltages available at required current levels ..
Regards,
IanP
thanx for ur suggestion ian but does the inverter work well in automotive environment, i mean , wont the car's battery get drained soon if i use an inverter...............
I don't hink you really need the -5 and -12V voltages.
For the rest, they can be easily implemented using easy to find parts, such as National's LM2576, for instance, or other parts of the SimpleSwitcher family.
Can you post the required currents? I can put together something for you.
VVV
badboyscad, I share the same idea of IanP.
It is very easy to build an inverter. And once you build it, it will be available for other applications when needed (when you need to use a soldering iron in your car, or a drilling machine, etc... and there is no mains plug around...).
Also, you will not need to dismount your pc. If you put a plug in the output of your inverter, just like a wall plug, you will be able to plug your pc just like if you where at home.
thanx for considering my request, VVV and all . the currents(DC)(for ATX form factor) required are -12V,+12V,-5V,+5V,+3.3V,Gnd. the 3.3V is particularly difficult to get. i've attached a ATX pinout diagram and a reqiured amperes info.
Why make AC from DC and then back again? Why not just build a new front end for the PCs original PSU? What happens in the PSU is that the AC is rectified and chopped up again to drive the pulse transformer. Rewinding the transformer for 12V will save the unnecessary step and work much more efficient.
I don't think rewinding the transformer so it works on 12V DC instead of 300-400V DC is practical. You would have to redesign all the circuitry around it.
Making a 12V DC to 300V DC switcher to supply a normal PC power supply is a possibility.