30 Aug '13, 3pm

Disabling under/over voltage protection on ATX power supplies

I’ve actually stepped up to the challenge. My ham radio club had a surplus 6m transceiver that wanted some ungodly amount of amps at 13.8V. 13.8V/20A supplies are out there, if you want to pay the 3-digit price. So, however, are 350W AT supploes, and they’re pretty much free. 15V/20A works out to 300W, so I thought I’d give it a try. I ended up stripping out most of the components on the secondary, then reusing the high-current ones. The transformer secondaries were, IIRC, wound with pretty heavy gauge wire, so I ended up paralleling the +/- 12 windings and using the +5 filtering components. Some tweaks to the voltage sense resistor divider and the overvoltage and overcurrent protection circuits, and, after load testing for a day, we were good to go. It’s still running — with overvoltage and overcurrent protection! I actually had three supplies, all slightly different, and...

Full article: http://hackaday.com/2013/08/30/disabling-underover-voltag...

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