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Re: x-ray transformer questions
Original poster: "Jack Vandam" <snotoir7674g-at-mindspring-dot-com>
Hi Bert,
Thanks for the interesting link! I may try to contact that person if his
email is still valid. Now all I have to do is find out what phase this unit
is.
The pcb tests look interesting and it may be worth opening the case to
extract a small sample of the oil to perform the tests.
Thanks,
Jack
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, September 25, 2004 7:59 PM
Subject: Re: x-ray transformer questions
> Original poster: "Bert Hickman" <bert.hickman-at-aquila-dot-net>
>
> Hi Jack,
>
> It's too bad it's not a GE X-ray transformer, since NONE of GE's X-ray or
> medical transformers ever contained PCB's. Also, your X-ray repair tech
> appears to be correct - see the following thread for some more interesting
> information:
> http://www.industrycommunity-dot-com/myforum/mike_gray/messages/41.html
>
> Check the Pupman Tesla List archives for "PCB's" - you'll find a number of
> posts that mention some simple tests for PCB's (does the oil burn or does
> it float on water? If so it's not PCB's). The odds are fairly good that
> your transformer contains mineral oil.
>
> Best regards,
>
> -- Bert --
> --
> ---------------------------------------------------------------------
> We specialize in UNIQUE items! Coins shrunk by huge magnetic fields,
> Lichtenberg Figures ("Captured Lightning" in acrylic), & Out-of-Print
> technical Books. Stoneridge Engineering - http://www.teslamania-dot-com
> ---------------------------------------------------------------------
>
> Tesla list wrote:
>
> >Original poster: "Jack Vandam" <snotoir7674g-at-mindspring-dot-com>
> >Thanks for the info. Unfortunately, I wouldn't be able to obtain the
> >measurements you speak of without opening up the transformer. Not
knowing
> >for sure whether or not PCBs are present, it's going to stay closed until
I
> >find out for sure. However, I will save this info for future reference
in
> >the event I do open up the transformer.
> >Jack
> >----- Original Message -----
> >From: "Tesla list" <tesla-at-pupman-dot-com>
> >To: <tesla-at-pupman-dot-com>
> >Sent: Saturday, September 25, 2004 1:47 PM
> >Subject: Re: x-ray transformer questions
> >
> > > Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
> > >
> > >
> > > Most of the larger units, such as yours, have a 7.5 - 10 kVA core.
> >Measure
> > > your core dimensions and I can give you a better estimate. Core
cross
> > > section is one of the most important factors with regard to the
magnetic
> > > flux.
> > >
> > > The 7.5 - 10 kVA rating is approx 75% duty cycle but can be exceeded
for
> > > short periods of time such as charging up large Marx bank caps, etc.
> > >
> > > If you plan to run it constant, they you would be wise to operate at
5-6
> >kVA
> > > as a maximum.
> > >
> > > The reason the power levels are not specified is because different
types
> >of
> > > buck/boost reactors (external) were used with these xmfrs, so ratings
> >depend
> > > on heat rise vs. time. You could determine the proper rating by
operating
> > > the xmfr in sec short circuit condition and carefully monitoring the
core
> > > temp with a thermister. Many modern multimeters have these probes.
> > >
> > > Core temp vs. time will give you a reasonable estimate of how much
power
> >you
> > > can operate at. Core temp should not exceed 180 degrees F. (max) for
most
> > > applications. You can carefully dry off a section of core and wipe
clean
> > > with a solvent. Then, using conductive epoxy, attach your
thermister. Be
> > > sure to keep this conductive epoxy away from the HV coils.
> > >
> > > Keep the core temp below 175 degrees F. with long run times and you
should
> > > be ok.
> > >
> > > This was our approach on a large X-ray xmfr we used to charge a 100
kV
> >Marx
> > > bank. It worked out to approx 12.5 kVA for short duty cycles less
than
> >25%.
> > >
> > > Be extremely care --- these things are killers. We attached a large
red
> > > rotating beacon to one side of the 220 to ground (120 VAC) so the
beacon
> >was
> > > on any time HV was on. Use a relay so it will energize as soon as
your
> > > control circuit applies any voltage to the primary of the xmfr.
> > >
> > > Dr. Resonance
> > >
> > > >
> > > > Tonight's questions concern a Westinghouse x-ray transformer.
There
> >are
> > > two
> > > > things I'm wondering about with this unit: its specs and input/
output
> > > > information.
> > > >
> > > > Here's what's on the label:
> > > > cycles 50/60
> > > > wiring 3D 8939
> > > > style 981928
> > > > Volts AC, KVA, and Amps are all blank.
> > > > Under the word "Westinghouse", there are the following tiny
numbers:
> > > 36233-D
> > > >
> > > > Can anyone figure out the complete specs with this info?
> > > >
> > > > Now for the input connections:
> > > > XFL, XFC, XFS, G, MA, A, AA
> > > >
> > > > Input hookup info?
> > > >
> > > > And, finally, there are two high voltage recessed terminals. One
has a
> > > > single center conductor; the other side has three (their
purpose?).
> >The
> > > > diameter of the sockets is 1.25". I did manage to obtain some
high
> > > voltage
> > > > cable at one point, but the end diameters are too large. I'm
> >considering
> > > > making new ends out of epoxy or if I could obtain the correct size
> >cable
> > > > economically, I would go with that.
> > > >
> > > > Dimensions are about 13.5x17x15 inches and it must weigh at least
250
> >lbs
> > > I
> > > > would guess. Not sure what I'm going to use it for, but my
purpose
> >right
> > > > now is to just find out about it and get it going, using an
appropriate
> > > > variac for current limiting of course.
> > > >
> > > > If anyone has any info on this or a similar unit, I would
appreciate
> >your
> > > > sharing of it.
> > > >
> > > > Thanks,
> > > > Jack
> > > >
> > > >
> > > >
> > >
> > >
> >
> >.
>
>
>
>
>
>