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RE: E-Teala6 and JHCTES Programs
Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
Terry -
Thank you for the information you have sent below. I found that the E-Tesla6
program agrees very well with the JHCTES program when you change the
Secondary Term in the JHCTES program from 36 to 29 pf or a reduction of 20
percent. The JHCTES then shows 87.66 Khz like the E-Tesla6. This also made
the JHCTES secondary circuit agree more closly with the primary circuit.
I have mentioned in the past on the List and on my Web Site that I recommend
reducing the space capacitance of the toroid and sphere 20%. This is why I
made the Sec Term input of the JHCTES a capacitance (more flexible) rather
than using physical dimensions.
Several years ago when I researched this problem I found that this reduction
made the JHCTES program agree with tests of real world coils. In the
equation
F = 1/(6.283 sqrt(LC))
I found that the LC product had to be reduced in order to agree with tests
of real world coils. I was not able to determine exactly how the LC should
be changed but did find that reducing the Sec Term 20% of the JHCTES program
gave very good results. It is interesting that Paul has found that the
inductance L rather than the capacitance C should be reduced. It could also
be that both parameters are involved. More testing is required to find the
truth.
I agree with you that a new Tesla coil program should be made as soon as the
necessary test data is available. For the present coilers can use the JHCTES
or similar programs and reduce the Secondary Term 20% and use the E-Tesla6
program to confirm the resonant operating frequency.
John Couture
-----------------------------
-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, March 18, 2001 7:53 PM
To: tesla-at-pupman-dot-com
Subject: Re: E-Teala6 Program
Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
Hi John,
E-Tesla6 is verified against a wide array of known tested coils. That data
is
included in the zip file as "data.txt". Comparing the program to the known
data is the only way I could keep such a complex program on the true track.
I know exactly where we differ. You find the frequency with Lsec and Csec.
That seems right, however, the actual effective secondary inductance at AC
resonant is LESS than the DC inductance. Paul Nicholson's research finally
figured that one out. E-Tesla6 consistently showed something was wrong and
the
early versions fudged it. However Paul's work finally found the correct
numbers and why. The secondary does not have uniform current through it and
thus it losses inductance at resonance (10-20%).
http://www.abelian.demon.co.uk/tssp/
http://www.abelian.demon.co.uk/tssp/pn2511.pdf.zip
http://www.abelian.demon.co.uk/tssp/pn1710/
I can't begin to explain all Paul's work in a single E-mail here, but the
relevant cut and past from
http://www.abelian.demon.co.uk/tssp/formulae.html
follows...
==========================
The inductance of a solenoid effective at its lowest self-resonant frequency
differs from the low frequency (Nagaoka) inductance due to the non-uniform
current distribution at resonance. The following two formulae may be used to
calculate the effective series inductance,
Bare coil:
Les = Ldc * pow( 8.0724 + 4.5129 * h/d, -0.8016) *
pow( 0.0079 + 1.384 * b/h, 0.2623) *
pow( 338.89 + 18.9111 * awg, 0.1493) *
pow( 0.346 + 4.23 * h, 0.0232) *
pow( 115.768 + 7.1 * sr, 0.0241) + 0.658311
average error = 1.3%, peak error = 2.8%
Toroided:
Les = Ldc * pow( 4.6675 + 5.5509 * h/d, -0.5983) *
pow( -0.0147 + 0.9557 * b/h, 0.131) *
pow( 5.2204 + 0.145 * awg, 0.0703) *
pow( 3.94 + 0.9199 * h, 0.0487) *
pow( 5.41 + 80.798 * sr, 0.0114) *
pow( -4.1441 + 14.3397 * td/h, 0.1537) *
pow( 0.312 + 0.58 * tb/h, 0.088) + 0.686997
average error = 1.6%, peak error = 4.5%
where
h = length of secondary winding, metres;
d = diameter of secondary - metres;
b = height of winding start above ground - metres;
awg = wire gauge, AWG;
wd = 7.348e-3/pow(1.122932, awg-1) (wire diameter - metres)
sr = spacing ratio = turns * wd/h
td = toroid outer diameter, metres.
tb = height of toroid plane above the top of the winding, metres.
===============================
Perhaps you could incorporate the above data into your program. I still am
using an older method and will change E-Tesla to the above latest and
greatest
formula when I get a chance... Paul also has a data base of 13500 coil
configurations at:
http://www.abelian.demon.co.uk/tssp/vsd/
In fact, one could write a whole new Tesla coil program using this new data
that whould probably be the most accurate program yet!! Hmmmmm..... There
is
a ton of data on Paul's site that will take years to fully digest...
Cheers,
Terry
At 06:44 PM 3/18/2001 -0800, you wrote:
>
>Terry -
>
>I checked your E-Tesla6 program outputs with the JHCTES program and
obtained
>the following results.
>
>Entered in the JHCTES Ver 3.2 for the Secondary circuit.
>
> Sec Rad 5.13
> Turns 1000
> Turns per inch 33.3
> Sec Term pf 36.0
>
>Outputs - JHCTES E-Tesla6
>
> Oper Freq Khz 81.05 87.66
> Coil Lgt 30.05 30.0
> Sec coil Ind mh 75.96 75.4
> Tot Sec Cap - pf 50.77 50.75
>
>How does E-Tesla calc the 87.66 from the above data?
>Have you ever tested the operating frequency of this coil?
>It appears your program and the Toroid/Sphere graph in my Tesla Coil
>Notebook are in close agreement. The graph shows 33 pf for the Sec Term.
>
>John Couture
>
>------------------------------
>