# Army Surplus power supply..

Discussion in 'Power Electronics' started by medictrode, Jun 9, 2013.

1. ### medictrode

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Feb 21, 2013
Hello all... I recently acquired an insanely large and heavy army surplus power supply that currently is not operational. http://yabe.chudov.com/PP-1104C_G-DC-Power-Supply/PP-1104C_G-Power-Supply-1.pdf
When it's powered up the breaker on the front panel will trip. I just got into the case so I don't have enough info to ask for advice yet, but had another question....

It uses a magnetic amplifier to regulate it's voltage. Obviously this is a crazy old school way of doing things, but I find it's method of operation fascinating however I can't wrap my head around it. Any simplistic explanation of how it operates would be helpful to myself and anyone else here who has never seen a dinosaur like this. Thanks for the help...

2. ### poor mystic

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Apr 8, 2011
Hi
My tutor discussed mag amps, I have only ever seen one example which had been used to regulate current to a lamp. I don't feel that a simplistic explanation will help you but a simple one might.
Wikipedia has a pretty readable article. Why not try Wikipedia, and come back with specific questions.

3. ### poor mystic

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Apr 8, 2011
Hmmm
You really need a pretty good familiarity with the graphical representation of functions if you are to follow any explanation I can give.
A steep function of the form y=m*x+c gives a wide range of output for a small range of input, whereas if m is smaller so will be the output range of values.
A mag-amp changes the value of m by biasing the saturation curve of a reactor core. Sorry! That's the best I can do. If that isn't helpful try not to worry; few people have even a vague notion of how mag-amps work.
I think it unlikely you'll need to work on the mag-amp itself. There's more likely rubbish in there somewhere.
Mag-amps just do not go wrong, they have no breakable parts. The fault is most likely somewhere else.

4. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,496
2,837
Jan 21, 2010

With all intended respect... We don't care a great deal whether you found the wikipedia article useful or not. What is important to us is that the original poster found it useful.

5. ### medictrode

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Feb 21, 2013
Thank you guys for the help, much appreciated. I will check out the wiki, however I do understand the basics of that explanation you gave. I remember some of my teachings back in my school days about magnetic theory. I do have to say though the guys who came up with this stuff back in the early days were absolute geniuses. The mathematical equations to come up with this must have been insane. I have a great respect for that..

Anyway, thanks again, I will get into the insane heavy case this week and see what I find..

6. ### medictrode

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Feb 21, 2013
An update if anyone was interested..

The one poster was right when he said there isn't much that could go wrong in this thing. The problem was a faulty panel mount circuit breaker. I managed to find a similar physically sized one of the same amp rating in the shop and made some brackets to make it fit ok. After that it was fun to put a load on this supply and watch the thing regulate the voltage, great old school tech. Anyway, thanks all for the help...

1,071
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Apr 8, 2011