Originally posted by r0cket-:
<STRONG>I have a little power supply that's looking good to use with my SBC, but it only outputs +5VDC and +12VDC. Now, I'm not entirely sure that this motherboard can't be run off just the +5 and +12 (or even just the +5, for that matter), but assuming it can't, is there any easy way to get -12VDC out of either +5 or +12?
Check out Aaron Cakes website and look up the voltage inverter circuit. www.aaroncake.net The one based on the 555 works just fine, He numberd the pins wrong in the drawing (7 and 8 are swapped), but it is the same as astable operation as discribed in the data sheet.
you can get enough voltage out of it to power mobos that need the -12 for the serial port to work.
Almost nothing these days runs off of the - 5 though.