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Re: Primary size
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> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Primary size
> Date: Thursday, April 08, 1999 5:29 PM
>
> Original Poster: "Reinhard Walter Buchner" <rw.buchner-at-verbund-dot-net>
>
> Hi Jim,
>
> >Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
> >
> >I have heard (not having done extensive experiments myself) that having
> >diameter of the primary be comparable to the height of the secondary is
> >good from a field distribution standpoint. HOWEVER, this probably
> >applies to smaller table top coils, where the primary is serving as a
> >counterpoise for the top load. Electrum had the primary inside the
> >secondary, for instance. It is probably more an issue of coupling and
> >insulation (preventing arcing from primary to secondary).
>
> I fully agree.
>
> >The coupling issue is, in turn, an issue of charging currents
> > for the primary circuit (more current means you can use
> > higher coupling)
>
>
> Why? I would think it is the other way around (for the same
> coil). Meaning for a given coil setup, the more primary current
> I have flowing, the less I can couple. Otherwise I get turn to
> turn flashovers, esp. if my topload is small (i.e the secondary
> runs "too unloaded") Or am I missing something here?
>
> Coiler greets from germany,
> Reinhard
>
I think that as the coupling increases, your secondary sucks more power out
of the primary per cycle. This causes the voltage to drop more quickly,
which makes the streamer die out, because there isn't a reservoir of charge
to keep it growing. Therefore, if you have better coupling, you'll get
better spark performance, but only if the primary charging can keep up. Of
course, you can over couple, too