X-Ray Transformer

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Samuel Berman
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X-Ray Transformer

Post by Samuel Berman »

It's been a while since I've posted here and I wanted to share some updates. I just finished my first semester of college, and now that I'm back for winter break I'm continuing my fusion efforts. I managed to find an old x-ray machine listed online, and picked it up for only $100!
machine in trailer.jpg
It's an old 60hz unit from 1978. I was a bit worried that it might contain PCB's, but after contacting the manufacturer and doing a few crude tests of my own, I'm satisfied that it doesn't.
transformer.jpg
Transformer Label.jpg
It seems to be a slightly older model of the unit that Ameen Aydan used for his fusor in this thread:viewtopic.php?f=11&t=13446. Unlike him, I was able to find a schematic of the transformer, and it looks very similar to the one he drew. I'm glad to see that this transformer has already been used to achieve fusion.
Transformer Schematic.png
Since I got the whole machine and not just the transformer, I had fun taking apart the rest of it and am hoping to make some of the money back by selling the xray tube.
xray tube.jpg
I have a variac on the way, and once it arrives I'll update this thread with some tests. I plan to make some arcs with it, using one or two MOT's for ballasting. Then I'll figure out how to modify it for fusion purposes.
Samuel Berman
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Richard Hull
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Re: X-Ray Transformer

Post by Richard Hull »

Excellent buy! The best of the best. Indestructible ancient technology. Wear a truss when moving it about.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Samuel Berman
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Re: X-Ray Transformer

Post by Samuel Berman »

My variac arrived, and I used it to fire up the transformer using 2 MOT's in series with the primary for ballasting. I got some small arcs with as low as 16 volts input. The unit runs on 240.
IMG_1050.jpg
As the voltage is turned up, the current increases and the arcs change their appearance.
IMG_1038.jpg
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Richard Hull
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Re: X-Ray Transformer

Post by Richard Hull »

If the internal diodes are silicon, you can ruin them by arcing the supply. Remember, air arcs present a load close to a dead short!!! In short, never, ever arc a high voltage DC power supply.

Sure, it might survive arcing, but if it doesn't, are you prepared for the mess of having to go inside, lift the top off, let the oil drain off the guts and then replace all those internal diodes in the string??
Such wonderful fun that is. Never deliberately arc a DC high voltage supply even at low input voltage. Hopefully, the MOTs buffered the current to allow the diodes to survive

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
John Futter
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Re: X-Ray Transformer

Post by John Futter »

Of course the arc may now be an AC one due to shorted diodes.
If you want an arc build a Tesla coil, if you want to succeed in fusion make sure you never see an arc also make sure that you have put a series resistor (Ballast resistor ) to limit the diode current to within the diodes max rating..

Faulty x-ray transformer / diodes here we come!!!
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Samuel Berman
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Re: X-Ray Transformer

Post by Samuel Berman »

Thanks for the tip. I'm aware that arcing creates a dead short and can create high currents on the secondary. However, I thought that with a ballast this wouldn't be a problem. The transformer is rated for 300ma (at least for short periods) at the output, and the current for my tests should have been lower than 20ma. Is my reasoning correct, or am I missing something? Perhaps current spikes on the secondary are the concern?
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Richard Hull
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Re: X-Ray Transformer

Post by Richard Hull »

The diodes might be OK. The way to tell is to place a high voltage DC meter on the output and variac the voltage up a bit if it deflects backwards that is a good sign that your polarity is wrong. Switch the leads and it should go positive. All all events verify that it is DC by switching the leads and observing opposite deflections. Don't go too high on the variac, you just want to see opposite deflections.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Samuel Berman
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Re: X-Ray Transformer

Post by Samuel Berman »

I tested the diodes, and they are fine. I'll refrain from arcing the transformer just to be safe. I also fired up the x-ray tube using a second variac to control the filament transformer, and confirmed that the tube definitely still works.
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Rich Feldman
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Re: X-Ray Transformer

Post by Rich Feldman »

Next step is to put a milliammeter between the M1 and M2 terminals.
There's no easier way to monitor the current in secondary circuit.

If the power supply didn't already include an overvoltage protection device between M1 and M2,
and you didn't have an external jumper,
I bet you would have had an air arc at one or both of those terminals.
All models are wrong; some models are useful. -- George Box
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Samuel Berman
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Re: X-Ray Transformer

Post by Samuel Berman »

I'll definitely look into doing that next.
Samuel Berman
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