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RE: [TCML] Single ear piglet

I'm not doing mine exactly like David, but here's what I've been doing for years:

http://www.classictesla.com/hot-streamer/adam/bigass_coil/schematic.pdf

As to being bad, most folks don't recommend doing this with a NST, though I have. It does change how most folks do their safety though. You can't have a three point safety and your case has to float.

I don't get your question about faults. A fault on the HV side is current limited on the LV side by my ballasts. A fault on the LV side is covered by fuses (in my 100 amp disconnect) and a breaker (not shown).


Adam

--- On Thu, 4/23/09, Jim Mora <wavetuner@xxxxxxxxx> wrote:

> From: Jim Mora <wavetuner@xxxxxxxxx>
> Subject: RE: [TCML] Single ear piglet
> To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
> Date: Thursday, April 23, 2009, 1:50 AM
> Hi David,
> 
> Let me see if I am following you. This then RF grounds the
> inner turn of the
> primary, Yes? I know others do this and tie it to the
> secondary base. So
> there is no arc over from the inner turn to the coil lower
> turn. I seem to
> remember something bad about this but can't peg it. I
> believe this is the
> hallmark of an Oudin coil construction.
> 
> Is this what you are doing? The return has the advantage of
> being RF but
> what is there is a fault in the transformer... the LV goes
> to the operator
> controls... do we trust the RF ground resistance to mains
> to blow a breaker
> or am I missing something?
> 
> Jim Mora
>  
> 
> 
> 
> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx
> [mailto:tesla-bounces@xxxxxxxxxx]
> On Behalf
> Of David Rieben
> Sent: Wednesday, April 22, 2009 4:31 AM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] Single ear piglet
> 
> Hi Jim, Gates,
> 
> What "I" do with my single eared piggy is hook the
> tank's case "return" to the opposite side of the SG/
> capacitor form the "ear".. In other words, the tank
> case is tied to RF ground. Since my pig is resting on
> a plywood base and fastend via its polemunt brackets
> to 2x4 cross beams inside of my control panel, I am
> able to effectively isolate the RF from the mains ground.
> As a matter of fact, there is no direct connection to
> mains ground at all with the my piggy, since proper
> input hookup leaves the middle LV bushing un-
> grounded.
> 
> I see you also mentioned  that your transformer's
> rated
> output is 30 kV with 120 volts input. I am assuming
> that this is some type of potential transformer as
> 30 kV seems rather high for typical primary distri-
> bution voltage. Also, as Herr Zapp has mentioned,
> this is also a very high primary voltage for a typical
> Tesla coil circuit and few of even the largest coils run
> on primary circuit voltages of this magnitude. List
> member Scot "bunnykiller" D. is about the only one
> that I can think of off the top of my head that has
> succesfully ran ~ 30 kV in a standard, air-insulated Tesla
> primary circuit and he can tell you firsthand of the
> inherent
> problems with running voltages this high that H. Zapp has
> already mentioned in his posting to this thread. If it's
> at
> all feasble for you, you may wish to consider obtaining
> a pole pig with a more typical input voltage (output
> voltage, for our use), like 13.2 or 14.4 kV. If it's not
> feasable, then I suggest that you talk with "bunnykiller"
> to get some insight from his experience. Of course,
> one advantage to using a higher primary voltage is that
> you can get by with a notably smaller primary capacitor,
> capacitance wise, per E = .5 CV (sqrd), where E is the
> energy, in Joules, C is the capacitance, in Farads, and V
> is the potential, in volts. However, the increased
> dielectric
> requirements for the additional voltage standoff pretty
> well
> render this advantage moot.
> 
> David Rieben
> 
> 
> ----- Original Message ----- 
> From: "Jim Mora" <wavetuner@xxxxxxxxx>
> To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
> Sent: Tuesday, April 21, 2009 7:54 PM
> Subject: [TCML] Single ear piglet
> 
> 
> > Hi Gates,
> >
> >
> >
> > Dr, Resonance does this on all his coils this way. I
> just set one up to 
> > his
> > specs and many list member ground one horn in a dual
> horn. I'll let Dr.
> > Resonance advise on this. Generally the inner turn of
> the primary is
> > grounded to the coils RF ground. You need a return
> path so the pig may be 
> > at
> > mains ground too, something I don't like much. Filter
> the nasties!.
> >
> >
> >
> > Jim Mora
> >
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla 
> 
> _______________________________________________
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> 
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> 



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