A year ago I posted a high density PSU design for my laptop (180W, 19.5V), but the project ended up being scrapped due to I sold that laptop and I no longer need it.
I decide to revive the project with a twist -- to shoot for much higher power, in a similar size, with active cooling.
This time, I'm building the PSU for my ITX build which is based on HDPlex 400W DC ATX. I need a 450W AC-DC module to extract the full potential of the DC ATX, but the highest power rated power brick is Dell 330W brick for Alienware laptops.
Also, I would like to get rid of that huge power brick, and to build a smaller one that fits inside the case of my ITX build (NFC S4M).
I talked with Larry from HDPlex, and he is actually designing a 700W DC ATX, and that opens a whole new possibility -- dual core GPUs in a tiny ATX.
To make that work, a 760W+ AC-DC PSU is needed to power the entire thing, and that's what I'm designing.
The target is simple -- to build a 750W+ PSU that fits in NFC S4M, I prefer the space between top of GPU and chassis wall. This allows me to install longer GPUs (compared if I put it on the rear end of the card), besides it allows for better cooling of the GPU.
From my measurement of my own S4M case as well as its SketchUp model, I determined the maximum size of my design: 150mm long*55mm wide*28mm thick. That's 3.3W/cm3 or 54W/in3 power density for a power supply with PFC, bulk capacitors and casing.
It's an ongoing project, so it may see major modifications.
So far, I have the schematics, some primitive calculations on power path and simulations on key circuits done.
I will need to assign MCU pins as well as to do the PCB artwork, but I would like to halt to listen from your suggestions.
FYI, the BOM is $112 at 500 units quantity. I don't plan to sell it for now, but since it's CC-BY-SA, I hope someone else can make it a product for my fellow mini ITX lovers.