Re: toroid question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Allanh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>

It has occured to me that using a toroid with no conducting material in the
center in effect places a
shorted turn in the magnetic field and would cause
very high current to flow. Upon testing my theory on
my coil, I found very little difference in the two types.
I would like to know why the shorted turn toroid doesn't
consume great quantities of power.

any ideas?

allan

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 23, 2002 5:56 PM
Subject: Re: toroid question


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Mddeming-at-aol-dot-com>
>
> In a message dated 1/23/02 10:15:48 AM Eastern Standard Time,
tesla-at-pupman-dot-com
> writes:
>
>
> >
> > Hi Godfrey,
> >
> > in my opinion there is no need to deal with toroids, whose hole in the
> > center is <=zero, or very small, relative to the outer diameter. The
> > outer diameter is probably choosen in a relation to the size of the
> > secondary or to sparklength, in order to get a nice "shielding effect"
> > for corona (i remember John Freau proposing D.toroid=~"desired
> > sparklength"/2.5), or considering the whole TC in a Pspice-simulation
> > for output power and voltage. The diameter of the "cord" should be in a
> > relation to the secondary outbreak-voltage (remembering again John:
> > d.toroid = "desired sparklength"/10, as a start). But the ROC of the
> > torus will never be really perfect, even if having a spun toroid. And as
> > soon we get breakout, the toroid will no more be smooth anyway, 'cause
> > the streamers and sparks are like "needles", and the jon-cloud may be
> > adding capacitance. Personally i try to choose a ratio of diameters, -
> > not at all scientifically - , which gives me a good feeling about
> > proportions. And this is not one with zero inner hole radius, which
> > might typically be not much less than the cord radius.
> >
> > Anyway i'm keen to see your approximation to the "true capacitance" of
> > an isolated toroid, probably with an estimation of accuracy. This seems
> > to me of great value, even, if after all, either we may find Bert Pool's
> > formula just good for our purpose or utilizing a more elaborate formula
> > in our calculations (i.e. spreadsheets).
> >
> > Cheers,
> >
>
>
> Hi Godfrey, Kurt, All,
> Capacitance is also affected to some degree by what's in the toroid's
hole. A
> toroid with a "pieplate" center will have somewhat different capacitance
than
> one with a "spoked wheel", which will be different from one with 3 plastic
> "struts", etc.
> Matt D.
> G3-1085
>
>