Positive HV Fusor

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Eldarion
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Positive HV Fusor

Post by Eldarion » Wed Nov 26, 2008 4:58 pm

I have come across many references saying that fusors may be run using a positive HV power supply although few people choose to do so. Does anyone know how to do this? I have not been able to find references for that.

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Chris Bradley
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Re: Positive HV Fusor

Post by Chris Bradley » Wed Nov 26, 2008 6:44 pm

I've said it once. last time:

I went to 'search' [on the top line] and entered 'lethal' and instantly got;

viewtopic.php?f=6&t=2214&hilit=lethal#p13187

There are plenty of link to your question.

Please use the search.

Dan Tibbets
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Re: Positive HV Fusor

Post by Dan Tibbets » Wed Dec 03, 2008 9:57 pm

As far as I know there is no absolute barrier against a pos grid 'pushing' ions towards the center vs a neg grid 'pulling' them. Though I have not been able to find a good reference, I've heard it mentioned in several places. I beleive that the Elmor, Tuck and Watson approach utilized this method. It is a part of the Pollywell approach.
The only concern would be if you used the vacuum vessel/ shell as the grid. This would be dangerous as the voltage would be exposed on the surface. A positive grid inside the vessel with the shell being grounded would not be any different from a neg potential driven fusor from a safty standpoint.

Both a central negative grid and a positive outer grid could be used ( and I'm sure has been) in tandom. It would be more complex with essentially two power supplies, feedthroughs, standoffs, etc.
I've speculated that this approach could be used with modest increased complexity with a center taped transformer like a oil igniter or neon sign transformer. One lead could go to the neg grid while the other lead could go to a pos grid ( with appropiatly orentated diodes). This could allow full exploitation of the voltage rating of the transformer. I'm not sure what the effect would be on the aviable current. And the shell would possibly need to be larger to accomidate the increased spacing needed for the extra electrode. One feethrough with two wires could be used if adiquite insulation, etc was used.

Dan Tibbets

MarkS
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Re: Positive HV Fusor

Post by MarkS » Wed Dec 03, 2008 10:03 pm

I've often wondered why not two grids, the outer one at HV+ and the inner either at ground or at -100V or so. The shell, of course, would still be grounded and neutral. If that configuration would work one could use the cheaper and more readily available HV+ supplies, and a cheap lab supply. The drawbacks being the cost of two feed thrus (one hv, and one regular electrical feed).
-Mark Siegel

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Frank Sanns
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Re: Positive HV Fusor

Post by Frank Sanns » Wed Dec 03, 2008 11:29 pm


Eldarion
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Re: Positive HV Fusor

Post by Eldarion » Wed Dec 10, 2008 6:20 pm

It has been used before.

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