Thread: DC/DC ATX PSUs?

ATX DC-DC power supplies are the holy grail. Like you said, some have tried to make their own, others have tried the "astec laptop power supply" from www.mpja.com
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Plans & Pics of my system at http://wizardpc.terrashare.com

from what i understand, they are ATX

try this: www.keypower.com/DC_power/DX-250H.htm . You could dissasemble the unit and reduce the size that it takes up. You will need to pay attention to cooling though. Hmmm, maybe because it is doing DC-DC and more efficient than standard PC Power supplies, it runs cool enough to not need external cooling (FAN).

When they get more in stock, I will recieve one. I ordered one in November from the US/California office, and they weren't expecting any until Jan or Feb. I can wait...maybe.

how much are those PSU's? I couldnt find prices.

Nope, it will most likely need a fan, regardless of how efficient it may be... Also, most desktop ATX PSU's have a PCB inside that is almost the same size as the box; there's not a whole lot you can do size reduction-wise.

Remember, a standard 120/220VAC ATX PSU is really a DC-DC PSU, but with a much higher input voltage than a 12VDC unit. The incoming AC is rectified and filtered to DC at a potential of several hundred volts.

Part of the reason why you cannot readily purchase an ATX PSU in miniature form is the fact that the Intel guidelines for ATX require certain cooling, space, and current requirements. A custom-designed PSU can get away from this, but in order to be true "ATX" certified, it needs to meet certain criteria. Not a lot of computer companies see the need to manufacture subminiature versions of their supplies, and even then they usually are very specific (for example some book PC's have only high current +12V and +5V outputs and the rest of the PSU is actually built in to the motherboard.)

Also, the laptop PSU's people are buying from such sources as MECI and MPJA are *NOT* ATX compatible in that they lack the +3.3V output and PS_ON lead that the ATX specification requires. Also, the current output on the +5V and +12V on these units is fairly weak -- it may have trouble electrically and thermally powering higher speed processors, especially those made by AMD which are notorious for high current requirements.