XRF X-ray transformer

[Richard Hull]

I was lucky enough to have just picked up a large XRF, X-ray transformer. Well, not picked up the sense of lifting it, but obtaining it. It was offered to me as part of a takedown of a large X-ray Flourescence spectrometer by a local college. The deal was you take it all or nothing. The system, all up, weighed over a ton and formed two full table top type steel lab units. I will speak only of the massive x-ray transformer here.

I have placed images below from the manual. (Yes, I took home 30lbs of operational manuals that came with the machine).

I figured some might like to see the guts of a typical X-ray transformer and here of its specs. This unit is vastly larger and much more "beefy" than a typical, older dental x-ray transformer which might weight 100-200lbs. The four lifting eyes on each corner give a clue of the size and mass. The gross tanked weight with its 40 gallons of Diala-X oil is 725lbs!! (Where did I put my truss?)

The rated power out of the secondary is 7800 watts intermittent and 5600 watts continuous! What this system needed that energy for, I will never know. The manual states that at 75kv, the model 780 unit, (which I have), is capable of supplying 100 ma intermittent and 80ma continuosly. The manual admits that most x-ray tubes will not be operated at these levels. Thus, this monster is over built.

The full wave bridge is composed of 4- 120kv large, solid state, stick rectifiers. (see image) The unit contains a 150kv, 0.1 ufd internal capacitor with an internal voltage divider to supply a voltage and current monitoring output. The internal image doesn't show this,(model 760), but a third image of the partially dismantled transformer platform does.(model 780)

There are 4 motors under oil that just continuously stir and circulate the oil. This beast is over built!

I am preparing for complete teardown of fusor IV for the first re-vamp of my system since 2005

Richard Hull

[Rich Feldman]

Wow, that's great.
I will go buy a truck, in order to be prepared when a similar opportunity knocks at my door.

[Richard Hull]

Fortunately, I had a fellow HEAS member that owned a small trailer. We hauled away about 1500 lbs of stuff, total. Only something with a ramp would do here, which the trailer had. You would have quite a time getting the 700 + pound item in a high truck bed....But, where there is a will, there is a way.

The original post was to be part of a "teachable moment" for those who have never plumbed the mysteries of the X-ray system transformer.

Richard Hull

[John Taylor]

Thanks for sharing that with us, Richard. I love how solidly built that case and the mounts are. Its nice that it includes the oil circulating pumps, although most of us probably wouldn't use enough power to significantly heat up that volume of oil.

Are you planning on modifying it for a HV PS? Of course, it would probably be just fine as is with a large enough Variac.

Thanks for sharing!

[Richard Hull]

The large, new X-ray Xfrmr is good to go as is. No mods necessary, though I am considering pulling that 0.1 ufd, 100kv cap out. I don't like the stored energy. It is already a negative hot, full wave supply, as are most old x-ray systems, so no hassles there at all.

I will definitely be hooking it up to my already extant 28 amp 240 volt variac. That has been part of fusor IV's setup since 2005.

Richard Hull

[DaveC]

The can for the HV assembly is kind of standard for this vintage of X Ray HVPS.

They were all heavily built, filled with gallons of Transformer Oil and many pounds of conservatively rated mains (usually) frequency transformer steel.

There are actually lots of these systems around to be had at the various Industrial Xray servicing firms. The newer HF switch mode PS designs are about 10X lighter and usually similarly robust, due to sophisticated protection, rather than innate conservatism of design.

These older pups are almost indestructible unless you are particularly persistent in your overstressing.

Nice find Richard, and thanks for sharing the interior views. Brings back a few memories.

Dave Cooper

[Richard Hull]

Went to the scrap place last weekend and netted ~$250.00 trading in the many aluminum and large bronze castings shorn from the XRF system. I retain only the 750lb X-ray transformer, a 550lb voltage stabilizer, a 200lb isolation transformer, the 28 amp 240 volt variac, the fabulous 1397 Welch pump and a huge 20-inch diameter, 3/4-inch thick bronze, 360 toothed worm and spur gear.

The lab is getting far too packed up with stuff to be used or sold at some future date.

While I am about to receive my first full retirement SS check, I plan on continuing full time work at least through the end of 2012 and maybe longer, I lust to be in the lab full time. Asked when I will really fully retire, I reply, when I wake up one morning and just don't want to go to work anymore. 43 years of going to work at the same place can get old, but it still challenges me just enough to interest me.

Richard Hull

[johnp]

This looks very much like an X-ray transformer I got rid of a couple years ago. The output specs were similar to yours, though I think it had a 3-phase 440 volt input. Hugely heavy even after I siphoned the oil out.

[Jerry Biehler]

"a huge 20-inch diameter, 3/4-inch thick bronze, 360 toothed worm and spur gear."

Oooo.... That would be nice for a large telescope.

[Richard Hester]

Outside under a tarp, I have what I think are the guts of an old Philips X-ray diffraction machine that I picked up for ~$200. It boasts a 60kV, 60 ma output. The transformer tub has water cooling connections, so I expect it could pump out close to full power 24/7 with the right pump/radiator/fan setup. The rub is getting it down into my basement, as it weighs around 400 pounds. The transformer tub is probably about half the weight of the whole setup, and is in a pot about half again as big as a 5-gallon bucket.

[Richard Hull]

Jerry is spot on as regards a telescope. I have several refractors and a new 12 Meade Schmitt Cassegrain. As an old amateur astronomer, I hope to sell the worm and wheel to an amateur with big ideas and asperations.

It will only need a 1/4 rpm motor to rotate the polar axle once per day. A true sidereal rate could be achieved with a variable frequency drive shifting the synchronous motor only a fraction of a cycle or so.

The worm assembly is a fabulous item in itself as it has a small chain drive 600 rpm synchronus motor through a shiftable transmission set up for fast and slow slewing of the worm.

A true telescope makers dream!!

The bronze wheel is worth over $190.00 as melt scrap alone!!

Richard Hull

[Jerry Biehler]

I have a 10" LX200 myself. Hope to do some astrophotography this summer. Got a real nice CCD camera, 6.3MP, vacuum enclosure, sensor cooled down to at least -30c in air, lower with water cooling. Super sensitive. I built an off axis guider for it last year and have a filter wheel with R,G,B,L, and Ha filters ready.

Of course, i would put a servo motor on the worm and make a go-to.