# Re: Sphere/Toroid Comparison Chart

```Original poster: "Kurt Schraner by way of Terry Fritz <twftesla-at-uswest-dot-net>" <k.schraner-at-datacomm.ch>

John C., Matt D., Terry-

John, your posting has made me to take another look at the table, Matt
D. has posted Thursday, May 03, 2001. I need to point to two facts, in
case, somebody likes to make use of this table. In any case, however,
beeing it a toroid or a sphere in TC use, I would rather prefer, to make
the E-Tesla6 calculation. The 2 facts are:

1.) Error here, in definition of diameter: NOT center-center, but
outer (maximal) diameter of toroid!!! (plausibility: Bert P.'s Eqn.)
¦
V
> C-C        Chord Nom.
> Toroid     Toroid     Cap       Equiv.Diam. Equiv.Diam.
> d1(inches) d2(inches) pf       sphere (in.)  sphere (m)
>
> 8          4.00     7.723          5.47      0.1390
> 8          6.00     4.540          3.22      0.0817 not feasible
> 10         4.00     10.675         7.56      0.1921
> 10         6.00     8.243          5.84      0.1484 not feasible
> 12         4.00     13.262         9.40      0.2387
> 12         6.00     11.585         8.21      0.2085
> 14         4.00     15.574         11.04     0.2803
> 14         6.00     14.605         10.35     0.2629
> 16         4.00     17.675         12.53     0.3181
> 16         6.00     17.359         12.30     0.3125
> 18         4.00     19.607         13.89     0.3529
> 18         6.00     19.893         14.10     0.3581
> 20         4.00     21.402         15.17     0.3852
> 20         6.00     22.245         15.76     0.4004
> 22         4.00     23.083         16.36     0.4155
> 22         6.00     24.444         17.32     0.4400
> 24         4.00     24.668         17.48     0.4440
> 24         6.00     26.512         18.79     0.4772
> 26         4.00     26.170         18.55     0.4711
> 26         6.00     28.469         20.18     0.5124
> 28         4.00     27.601         19.56     0.4968
> 28         6.00     30.329         21.49     0.5459
> 30         4.00     28.969         20.53     0.5214
> 30         6.00     32.103         22.75     0.5779

2.) John, I was not able to find a satisfactory way, using the equations
I find on your website, to represent the above table (trying quite a
number of some possible input data errors about C-C vs. outer d1).

Cheers
Kurt Schraner

Tesla list wrote:
>
> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
>
> The overlap is not a problem with the Toroid Capacitance Graph I show in the
> Tesla Coil Notebook because I did not use Bert Pool's equation. The
> equations I used are shown on my web site. Look for  Secondary Terminal at
>
> http://home.att-dot-net/~couturejh/
>
> John Couture
>
> -----------------------------
>
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Sunday, May 06, 2001 9:04 AM
> To: tesla-at-pupman-dot-com
> Subject: Re: Sphere/Toroid Comparison Chart
>
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <Mddeming-at-aol-dot-com>
>
> In a message dated 5/5/01 2:52:15 PM Eastern Daylight Time, tesla-at-pupman-dot-com
> writes:
>
> >
> > Original poster: "Barton B. Anderson by way of Terry Fritz <
> > twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>
> >
> > Hi Matt,
> >
> > The toroid C value is obviously calc'd in these (standard toroid
> > equations) as well
> > as the spheres. But there is a problem with some. Toroid cord and
> > diameters overlap
> > on some which is impossible and the equation is then wrong for those
> > toroids (and
> > also wrong for the equiv. spheres). For example, the 8" x 6" toroid. The
> > cord is 6",
> > and therefore the outer diameter must be larger than 12". This is why the
> > capacitance
> > is way off on these particular impossible toroids.
> >
> > Take care,
> > Bart A.
>
> Hi Bart!
> Thanks for pointing out the impossibilities. The table was generated for a
> range of sizes, and since I was not trying to build an impossible size, I
> guess I overlooked the silliness at the lower (upper) end of the chart.
> Since some people are talking about metallic "garden spheres" in lieu of
> toroids, I thought a quick comparison might help.
> With egg on face,
> Matt D.

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