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Subject: Re: x-ray transformers: questions (and where to get them)
Date: Oct 20, 3:40 pm
Poster: Richard Hull

On Oct 20, 3:40 pm, Richard Hull wrote:

>Hi Folks-
>For those of you with x-ray transformers, I need some simple info: First, my unit was made in 1985. How likely is it to have PCB's? Secondly, it has primary ratings of 230 V at up to 120 A.

120 amps!!! ??? RH


Secondary voltage is 67.5 kV per side for a total of 135 kV. Is it OK to have a periodic arc now and then (I mean in case of accident?) Can I pull an arc to see if the thing works, without worrying about a blown tranny?


I would not test the thing this way. You might just kill it. Take the two HV leads from the trans and place them about 4" apart. (bare the ends). Connect a variac and slowly bring the voltage up in a dark room. If corona is seen on the leads then you are probably OK. RH


It also has a bridge rectifier in it that doesn't look too beefy, but then again the current is very low. Can the bridge handle a arced output?


Most certainly not! The thing is made for at most a few cycles of current at 10 times the rated current. It would snuff in a fraction of a second. RH

>Secondly, if you live near northeast NC, you may be able to find a transformer from Jim Wells, whose company is Merry X-ray and is located in Wake Forest, NC. He mentioned he had a few extras around, though most were three-phase. He gave me a super deal (super= $100) and in addition he was very knowledgeable about the equipment and helpful getting it loaded up.


That was a fine deal and a fair price. For local scrounging, you get an A+. Good luck with you find and be safe.

Richard Hull