X-ray transformer issues

For posts specifically relating to fusor design, construction, and operation.
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Dennis P Brown
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Re: X-ray transformer issues

Post by Dennis P Brown » Sun Mar 03, 2019 11:56 pm

A number of possible issues.

The outside terminal of the HV input wire using a crimp fitting will have excessive coronal discharge. I'd at least round out edges on the crimp and place the entire end under silicon.

Those nichrome wires will get white hot and the glass tubing will likely crack and break up. Ceramic is used for a reason - heat tolerance.

I assume the cart is grounded? Otherwise, placing the HV wire on it could create an electrocution hazard.

That metal stand off supporting your fusor is rather close to the HV terminal. There could be an arcing issue.

At normal fusor pressure, the exposed end of the HV ceramic end and its HV metal wire is still inside your chamber 'well' access port. A lot of power will be lost there via the plasma conductive path. I'd suggest a ceramic outer tube that extends well past the fusor wall for the port 'well'.

Joshua Turbyfill
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Re: X-ray transformer issues

Post by Joshua Turbyfill » Sun Mar 10, 2019 7:26 pm

Okay thanks for pointing those out.

I just made a new grid and I'll machine some new supports from porcelain tile.
1-min.jpg

Also the XRT works great. I've been playing around with it at 30kv and getting some nice arcs.
2 C.jpg

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Richard Hull
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Re: X-ray transformer issues

Post by Richard Hull » Sun Mar 10, 2019 9:25 pm

I hope you don't blow your HV diodes out arcing like that. If the diodes short, you might know it, but if single wave rectified, you will just have AC high voltage going to the fusor. One should never play, "look at the pretty arc", with a good DC high voltage supply. It is a good way to turn it into a bad or defective HV supply. If you like big nasty arcs, build a Tesla coil. Do not arc a high voltage DC supply, they are not made for that.

Try letting natural mistakes and mis-adventure destroy your supply. Try not to help the process along by arcing it.

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
Retired now...Doing only what I want and not what I should...every day is a saturday.

Joshua Turbyfill
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Re: X-ray transformer issues

Post by Joshua Turbyfill » Sun Mar 17, 2019 2:14 am

Alright, thanks for telling me.

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