Re: X-ray OOps! location of picture (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 27 Sep 2004 19:33:36 -0700 (PDT)
From: Peter Lawrence <Peter.Lawrence@xxxxxxx>
To: hvlist@xxxxxxxxxx
Subject: Re: X-ray OOps! location of picture (fwd)


wow, nice piece of iron!

hmmm, number one concern is how to hook up the primaries so that they have
enough inductance to keep the input current down when the secondary is open
circuit.  Try connecting all primaries in parallel and measuring the primary
current, then if that is low you might(?) try 2 x 2 series-parallel,
definately don't try all four primaries in parallel unless you know for
sure either 1) it has enough inductance, or 2) you have a very reliable
circuit breaker that you're sure will blow before you burn out your coils, 
or 3) you put a current limiting ballast in your primary circuit.

Basically, if you know how to connect a stack of MOTs, you should be able
to figure this out...

-Pete Lawrence, just my $0.02 worth...




>
>I suppose the location of the picture would help:
>
>http://www.dawntreader.net/xray/xray1.jpg
> 
>Carl Litton
>Hilton Hotels Corporation
>901-374-5747
>
>-----Original Message-----
>From: High Voltage list [mailto:hvlist@xxxxxxxxxx] 
>Sent: Sunday, September 26, 2004 3:53 PM
>To: hvlist
>Subject: RE: X-ray Power Supplies (fwd)
>
>Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Sun, 26 Sep 2004 11:49:54 -0500
>From: Carl Litton <Carl_Litton@xxxxxxxxxx>
>To: High Voltage list <hvlist@xxxxxxxxxx>
>Subject: RE: X-ray Power Supplies (fwd)
>
>Thank you.  Sounds very serious  - and I suppose justifiably as
>polychlorinated biphenyls are nasty cumulative metabolic poisons and
>cancer producers.
>
>The good news is that I used Doc. R's test and it looks like I'm clear
>on this one.  Now if I can just figure this device out and get it back
>in the oil before it absorbs any moisture!
>
>The half wave rectified DC pulse present at the output of the
>secondary(ies) is almost twice the AC reading at the same point yet I
>can find no capacitors for a doubler action to be taking place.  I have
>never seen a capacitor without a container but I have considered that
>the 2 wound masses that I first thought to be a second small xfmr could
>be acting as capacitors since their appearance is of alternating layers
>of flat metal (or plastic) and cloth.
>
>I doubt the DC would be of much use to power the primary of the TC we
>are building as sine wave is necessary for xfmr action.  The main
>transformer also appears to be split into 4 distinct coils with primary
>windings deep and secondary windings superficial.  (4) wires going in
>from the prim inputs  and (4)  20kV rated wires coming out of the
>secondaries going to the rectifier arrays.  
>
>In the absence of a capacitor, we propose to sever the connections
>before the rectifier and run suitable HV rated wire directly to the
>output terminals.  We also propose to operate this beast on a specially
>designed 100 Amp 120V (versus the rated 220) circuit to cut output
>roughly in half to around </= 60kV and 20,000VA.
>
>
>Carl Litton
>Hilton Hotels Corporation
>901-374-5747
>
>-----Original Message-----
>From: High Voltage list [mailto:hvlist@xxxxxxxxxx] 
>Sent: Saturday, September 25, 2004 10:54 PM
>To: hvlist
>Subject: RE: X-ray Power Supplies (fwd)
>
>Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Sat, 25 Sep 2004 07:06:04 -0700
>From: BrianB <brianb@xxxxxxxxxxxxx>
>To: 'High Voltage list' <hvlist@xxxxxxxxxx>
>Subject: RE: X-ray Power Supplies (fwd)
>
>Let me add one thing to Dr. R's post.
>
>The EPA coming after you is not an urban legend. I personally know a
>list member who had the EPA come after him (he wants to remain anonymous
>for obvious reasons).
>
>What happened was the EPA decided that this list members recent E-Bay
>purchase (which was in his possession) most likely contained PCB's and
>they gave him 30-days to prove it or be fined $10,000.00 They also said
>if he failed to respond they would come to the location where the item
>was received (his house) and inspect and catalog everything at his cost.
>
>
>Final outcome - This turned into a paperwork and legal nightmare not to
>mention a financial drain. Ultimately the item (which was never proven
>to have PCB's) was sent to a disposal site and he spent a lot of money
>in addition to the hefty disposal fees.
>
>Brian B.
>
>
>
>-----Original Message-----
>From: High Voltage list [mailto:hvlist@xxxxxxxxxx] 
>Sent: Friday, September 24, 2004 10:37 PM
>To: hvlist
>Subject: Re: X-ray Power Supplies (fwd)
>
>Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Fri, 24 Sep 2004 14:15:48 -0500
>From: Dr. Resonance <resonance@xxxxxxxxxx>
>To: High Voltage list <hvlist@xxxxxxxxxx>
>Subject: Re: X-ray Power Supplies (fwd)
>
>
>
>Caution:
>
>Many of these old X-ray sets contain xmfr oil with PCBs.  That's why
>they
>are "given away".  The oil disposal would cost approx $1,500 plus
>shipping
>to a disposal plant which uses a very high temp incinerator.
>
>If the EPA finds out you have it, and it does contain PCB, they will
>order
>you to dispose of the oil or else pay a $10K fine if they have to come
>and
>get it.  Either way, if it's PCB, you lose.
>
>Dr. Resonance
>
>>
>>
>>
>>
>> ---------- Forwarded message ----------
>> Date: Thu, 23 Sep 2004 19:42:01 EDT
>> From: Mddeming@xxxxxxx
>> To: hvlist@xxxxxxxxxx
>> Subject: Re: X-ray Power Supplies (fwd)
>>
>> In a message dated 9/23/04 6:16:14 PM Eastern Daylight Time,
>> hvlist@xxxxxxxxxx writes:
>> ---------- Forwarded message ----------
>> Date: Thu, 23 Sep 2004 16:48:20 -0500
>> From: Carl Litton <Carl_Litton@xxxxxxxxxx>
>> To: High Voltage list <hvlist@xxxxxxxxxx>
>> Subject: X-ray Power Supplies
>>
>>
>>
>> We just acquired a donation today of what I am told by the owner of
>the
>> x-ray repair shop is the power supply to an old 'Frankenstein' era
>x-ray
>> machine containing a large transformer and a capacitor that reportedly
>> hold a very large charge for a couple of days -- all covered in oil.
>>
>> It is an olive drab steel box 2' cubic weighing a little less than
>> 200lbs. with 2 large holes in the top looking down into some clear oil
>> and submerged metal.  Large cables come out of the top.  220 VAC input
>> to primary and spec. plate reads that secondary output is 120 KVP
>> (assuming that to be Kilovolts Peak) at a current of 330 m.a.
>>
>> Now, I need to know about such devices as this is seriously beyond my
>> little (relatively) 39 lb. 15 kV NST's  and appears that it could
>> actually be dangerous ;).
>>
>> Anyone with experience on hi-powered x-ray transformers  - would you
>> please direct us to any articles or information on care and feeding of
>> such a device and caveats about any salient differences one encounters
>> with this type of power supply compared to the usual MOTs, NSTs,
>> ignition coils, etc.
>>
>> [I'm sure more folks will add their thoughts, but XRay transformers
>are DC
>> devices and will kill you very quickly.  100kVDC is nothing to be
>> careless with - your first mistake could very well be your last.  As
>> Richard hull would suggest, make sure you always have a friend there
>with
>> a long 2x4 to push your body off the terminals and put the fires out
>(with
>> a non-H2O based fire extinguisher!)  SRR]
>>
>> Carl Litton
>> Hilton Hotels Corporation
>> 901
>> Hi Carl,
>>     If your interest is in really understanding how these monsters
>worked
>and
>> were used, I would recommend "The Fundamentals of X-Ray and Radium
>Physics,
>> 6th ed." by J. Selman, M.D. publ. by Charles C.Thomas, Springfield,
>IL,
>1980. .
>> Has a good practical section on HV power supplies. Used copies sell
>for
>about
>> $5-$7 on Alibris. Older copies (4th ed.1967)discuss 120kV vacuum tube
>> rectifiers, mechanical rectification etc.
>>
>> Hope this helps,
>> Matt D.
>>
>>
>>
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