How low can you go ?

[Modelworks]

PSU use a lot of voltages that were chosen for legacy reasons and have remained part of the pc system to retain compatibility. In the future that will be changing but for now we have to deal with a lot of different voltages from the PSU and this is annoying to me as an engineer who likes to supply circuits with what they need for the best efficiency.


I have begun a project to take a basic pc , motherboard , video card, hard drive, dvd drive , mouse and keyboard and looking at the various components determine what the actual voltage requirement really is for the device. Everything used inside a pc now uses a converter of some sort to change what the PSU delivers to what the actual device needs. I'm compiling a list for each pc component and then will use that to determine what voltage would really be best overall removing device specific power conversion from the process.

My reasons for doing this are many. I have wanted a pc that can be powered from battery without the need for using an AC supply with inverters and I am not paying the ridiculous cost for a DC powered supply that essentially mimics its AC counterpart.

Another reason is just to see how efficient a pc can become if a lot of the conversion losses are removed. Just how low can the 5V rail be lowered and still work inside the pc ? How many conversions are going on in the various components ? How much work would it be to power everything from 12VDC ? How much input voltage overhead is designed into the various components ?

I'm starting with the motherboard and I have a schematic for the motherboard I will be using so that will make things easier. I will post info on each component when I get them done.

 

[PreferLinux]

Very interesting! I have had similar ideas, including to do with making DC powered supplies, but only ideas. Nothing quite the same, though.

Actually, I think you'd want to put voltages up, not down, as that would mean less line losses.

I will be very interested to read what you find.