Re: E-Teala6 Program

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

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
>
>------------------------------
>