Re: [TCML] Can i use an NST as ballast ?

["David Rieben" <drieben@xxxxxxxxxxx>]

Hi Stefan,

Wrong. Any coil of wire will have some inductance
and as Jim Lux has already pointed out, the actual DC
resistance for 500 ft. of #12 AWG copper wire would
likely be around 1 ohm, or less. That would only "limit"
the current to 120 amps! Also, if DC resistance were the
sole ballasting agent, and the current was "only" 25 amps,
then 25 amps x 120 volts would still produce 3 kW of heat!
The wire would quicky become a good space heater and
finally melt from that much heat and little energy would be
left to make it to your transformer and ultimately, your
sparks. So inductive reactance IS the primary ballasting
agent with the spool of wire.

David Rieben


----- Original Message ----- 
From: "Teslalabor" <teslalabor@xxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Tuesday, October 26, 2010 10:18 AM
Subject: Re: [TCML] Can i use an NST as ballast ?


> Hi Dan,
> in which way the 500ft spool does the current-limiting? I think its mostly 
> resistive ballasting with only a small amount of inductive ballasting. But 
> if you have nothing else availlable, this is a good method indead.
>
> Stefan
>
> ----- Original Message ----- 
> From: "McCauley, Daniel H" <daniel.h.mccauley@xxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Tuesday, October 26, 2010 2:14 PM
> Subject: Re: [TCML] Can i use an NST as ballast ?
>
>
> > If you are looking for an easy solution to ballast one of the common 
> > 14.4kV GE potential transformers, look below.
> >
> > Terry Blake came up with the great idea of using a 500ft spool of 12AWG 
> > stranded wire from Home Depot as the ballast.  When wired in series with 
> > the 115VAC input to the potential transformer, it limited current to 
> > about 240mA output at 14.4kV.  What a great solution!
> >
> > You could probably also scale this for use with other transformers 
> > accordingly.
> >
> > Of course, for a pole transformer, the best ballasting solution is a 
> > Lincoln Arc-Welder which can be had for very inexpensively on craigs 
> > list.
> >
> > Dan
> > http://www.easternvoltageresearch.com
> > LED Sequencer Kit Available - VTTC Stacatto Controller COMING SOON!
> >
> >
> >
> > -----Original Message-----
> > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On 
> > Behalf Of Andreas
> > Sent: Monday, October 25, 2010 5:19 PM
> > To: Tesla Coil Mailing List
> > Subject: EXTERNAL: Re: [TCML] Can i use an NST as ballast ?
> >
> > Ok, the power output from my potential transformer will never be more 
> > than
> > the ballasting NST. So if my NST is rated 500VA i will get 500VA or less
> > from my potential transformer. But if i add two 500VA NST:s in parallel i
> > get 1000VA or less.
> >
> > Guess its time to find some MOT:s.
> >
> > Thansk for the help guys.
> > _______________________________________________
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> > Tesla@xxxxxxxxxx
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>
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