Where to find sufficient power supply?

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David Petroski
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Where to find sufficient power supply?

Post by David Petroski »

I am nearly finished with my first fusor, however I have had some trouble locating a transformer that meets my needs.

I am looking for a 10kV to 12kV transformer without ground fault protection and preferably manually variable. Is there anywhere that I can find one of these for a reasonable price online?
ian_krase
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Re: Where to find sufficient power supply?

Post by ian_krase »

Get a Variac (for the manual control) and an Oil Burner Ignition Transformer. Also I think that somebody here is selling an excellent Neon Sign Transformer (for a considerable price, as they are not common any more).
David Petroski
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Re: Where to find sufficient power supply?

Post by David Petroski »

ian_krase wrote:Get a Variac (for the manual control) and an Oil Burner Ignition Transformer. Also I think that somebody here is selling an excellent Neon Sign Transformer (for a considerable price, as they are not common any more).
Thank you, these look perfect!
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Dennis P Brown
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Re: Where to find sufficient power supply?

Post by Dennis P Brown »

I have two large NST (over twenty lbs each) and they both use ground fault systems and I use them very successfully to power voltage multiplier systems and start a plasma or energize high voltage circuits or test HV meters/diodes - depending on your application, not always necessary to have a non-fault controlled x-former. Don't pay a lot unless you really need one without that feature.
ian_krase
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Re: Where to find sufficient power supply?

Post by ian_krase »

Yeah.

GFCI transformers appeared first, and the protection protects against the electricity going back to ground by any route other than the transformer's intended return path. In many systems, this is exactly what is going to be happening.


A bit more recently, the lightweight, electronic neon sign supplies started appearing. These are actually useless for most purposes.

For whatever reason, oil burner transformers have largely ignored either of these breakthroughs, though the typical oil burner transformer has a lower current than an NST (by a moderate amount).
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Dennis P Brown
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Re: Where to find sufficient power supply?

Post by Dennis P Brown »

So, if you are doing a demo fusor, any high voltage but inexpensive system will achieve that. So, out of curiosity, why do you need a 12 kV x-former without a ground fault? Such a system is useless for a real fusor. Are you building something special - maybe high current? Most NST's, even without a ground fault system, will yield only a few ma continuous no matter what their name plate claims (they will surge to their rated value but in very little time, fall to a few millamps.) What you want, for high current, is a NST with the center tap removed; as the FAQ's show, not a job suited for most people. Even then, you still only end up with a 12 kV (far too low for fusion) but maybe now an acceptable current x-former that can now yield a few 10's of milli-amps current.
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