Finished testing the power supply card and mounting the power supplies on a piece of plywood. As mentioned before, it is four PC power supplies connected in series. The last three power supplies have their grounds floating so that it the end power will be 48V. The power supplies must be electrically separated since the chassis of the first supply is gnd, 2nd supply is 12V, 3rd supply is 24V, and the last supply chassis is 36V. I plan on adding a plastic cage over the power supplies to make them a little safer. The other option would be to take apart the power supplies and try to separate the chassis from the grounds.
If you look at the pictures there are a lot of extra power supply connectors that can be removed. The main 24 pin connector and the extra motherboard 12V connector are used.
What’s the cost of this monster…
4 PC power supplies (just checked Amazon, and they are $10 each). Board that ties the power supplies together ($27 and that got me 10 of the boards. Who knows what I’ll do with the extras.) Connectors to populate the boards (bought 75 connectors for $24 off ebay). My total cost was about $100, with plenty of leftovers to make another 5 or 10 of these.
Here are the pictures: First one shows the four power supplies with 48V on the DMM. Second picture shows the card dwarfed by all the extra connectors. Last picture shows the isolating power connector.