[600MRG] 48V switching power supply

[Ben Gelb]

Came up in discussion on on4kst chat, so thought I'd share with the group
in case there is other interest.

I've been using this 2000W 48V supply ($30 on eBay) to power my 630m amp:
https://www.ebay.com/itm/Sun-Microsystems-371-2219-900-2000W-Power-Supply-ORACLE-M8000-M9000-Server/152760352371

Works great. I've only used it on 110V mains so its limited to ~900W in my
case, but thats been fine. And supplies 12.6V as well as 48V so you can use
it to power both the drivers and the finals in your amp.

Needed some minor modification to get it to power on, and of course needed
to solder some DC connectors on that were actually usable.

This datasheet appears to be for a version that operates from 200-400VDC
(not AC input) but is otherwise the ~same supply. It includes specs for all
of the control signals and a (seemingly) accurate pinout:
https://americas.fujielectric.com/files/HVDC%2048V_2000W.pdf

I added pullup/pulldown on the following control pins:
- PS_ON (turns on the thing)
- FANC (makes fan not spin full speed all the time - ramps up and down
based on temp)
- PS_KILL (dont force shutoff)

I then kluged in an IEC C14 connector in place of the AC hot-plug
connector, and soldered some 10ga zipcord onto the 12V and 48V +/- solder
pads inside, and finally a nice thick piece of electrical tape over the DC
output connector.

Has been running my 500W amp for over a month now w/o any hiccups! Haven't
noticed any significant noise on 630m (but caveat is that I live in a very
noisy environment, and I might not hear it under the neighbor's dimmer
switches).

73,
Ben N1VF