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RE: E-Tesla 6.11 strange prediction

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-worldnet.att-dot-net>

Terry, Matt, All -

I did a check on Matt's coil using E-Tesla6 and found the toroid capacitance
reduction to be 57.3% compared to the approximate 20% reduction that
E-Tesla6 showed for other coils. Is this correct?

The basic resonance equation is
     Fr = 1/(6.283 sqrt(LsCs))
For Matt's coil Fr = 287730 hz    Ls = 13.76 mh

This gives Cs = 22.24 ph   Cs = Ctor + Ccoil

The Medhurst equation gives Ccoil = 8.14 ph
for a 2.1 rad and 21.16 Lgt secondary coil.
The coil self capacity (Ccoil) can also be found with the JHCTES program
without using calcs.

The effective capacitance of the toroids on the secondary coil is
     Ceff = Cs - Ccoil  = 22.24 - 8.14 = 14.1 pf (Ceff)

The isotropic (free space) capacitance of the toroids can be found by the
equations shown on my web site (Secondary Terminal) or by the Sphere/Toroid
graph I show in my books.
     Toroid #1  3.25 x 11.25 (OA) = 13.00 pf
     Toroid #2  4.25 x 18.00 (OA) = 20.00 pf
     Total isotropic capacitance  = 33.00 pf (Ctot)

The percent of capacitance reduction for the toroids when placed on the the
secondary coil is
     % Reduction = (Ctot - Ceff)100/Ctot
                 = (33.00 - 14.1)100/33.00 = 57.3%

This 57.3% reduction is much greater than the approx 20% found by E-Tesla6
for other coils.

It will be interesting to see what the actual resonant frequency tests show.
There should be two types of res freq tests.

    Test #1  Low test current in sec coil by feeding the coil at the bottom
with a function generator. The res freq is found with a freq counter.

     Test #2  High current in sec coil by operating TC at high voltage but
with only corona output. The res freq is determined using a storage scope
and Terry antenna probe. This res freq should be lower then in Test #1.

Comments welcomed.

John Couture


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, May 19, 2001 4:37 PM
To: tesla-at-pupman-dot-com
Subject: Re: E-Tesla 6.11 strange prediction

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Matt,

E-Tesla6 does a lot of rounding and scale fitting to improve accuracy with
lower grid sizes.  In other words, it "jiggles" the data a bit to give the
best results.  However, that causes some little discontinuities in tests
like you are doing here.  If the program did not do this, there would be
far greater error.  I ran a diagnostic plot just to check for basic
dimensions and such and all seemed fine:


The only way around this is to uses a higher grid size (longer time...) or
take the data you have and draw a smoother curve through it.  The rough
error here is about 4% which is a bit higher than I would expect.  It
really is also possible that there is some "real" discontinuity too, but I
sort of doubt it here since the data seems so well behaved otherwise.  I
ran your data that you gave with a 200 grid size and got the following:

C=22.23451 F=287737.94

With a 400 grid size (it is raining here too :-)):

C=22.30953  F=287253.72

It would be especially interesting to compare this data to your actual



At 04:26 PM 5/19/2001 -0400, you wrote:
>Hi Terry, All!
>While waiting for the rain to stop (4 days now) I tried doing some
>with the E-Tesla 6.11 program in which I raised and lowered the primary
>keeping all else the same. There is a discontinuity at 19.75" that I cannot
>explain. Is this a critical point in reality, or is it a computational
>anomaly caused by the finite math of the CPU?
>        It will take a few days after the rain stops for the Lab (garage)
>floor to dry out before I can take measurements.
>Primary Cap.Calc Fres Calc
>in.         pF                     kHz
>16.50 22.23451 287.737
>17.50 22.32667 287.143
>18.50 22.43735 286.434
>19.50 22.55733 285.669
>19.70 22.55771 285.669
>19.75 22.55710 285.669
>19.80 24.25782 275.477
>19.90 24.25782 275.477
>20.00 24.25782 275.477
>20.50 24.29766 275.251
>21.50 24.66628 273.186
>22.50 24.79134 272.496
>23.50 24.96715 271.535
>24.50 25.26754 269.916
>25.50 25.60428 268.136
>26.50 25.96334 266.275
>Here is the other data from one run:
>E-TESLA  V6.11C  November 21, 2000
>Grid Size = 200.000000
>Scale Multiplier = 1.000000
>Terminated Coil
>Ceiling Distance = 96.000000
>Wall Distance = 48.000000
>Primary Height (Inner Turn) = 16.500000
>Primary Inner Diameter = 6.375000
>Primary Outer Diameter = 24.375000
>Primary Height (Outer Turn) = 16.500000
>Strike Rail Height = 25.000000
>Strike Rail Diameter = 30.000000
>Secondary Base Height = 25.000000
>Secondary Diameter = 4.280000
>Secondary Length = 21.160000
>Secondary Inductance (mH) = 13.760000
>Terminal-1 Height (center) = 51.799999
>Terminal-1 Cord Diameter = 3.250000
>Terminal-1 C-C Diameter (toroid only)= 8.000000
>Terminal-2 Height (center) = 55.400002
>Terminal-2 Cord Diameter = 4.250000
>Terminal-2 C-C Diameter (toroid only)= 13.750000
>Top Voltage = 360.000000
>Matt D.