Re: Tesla Coil Operation

To: tesla-at-pupman-dot-com
Subject: Re: Tesla Coil Operation
From: "John H. Couture" <COUTUREJH-at-worldnet.att-dot-net> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Tue, 09 Feb 1999 21:38:08 -0700
Approved: twf-at-verinet-dot-com

  Antonio -

  Are you saying that with your program the mutual inductance has to be
estimated by the program user and entered into your program? How do you
estimate the mutual inductance? The JHCTES program calculates the mutual
inductance using information shown in Terman's book. The mutual inductance
is then used to find other TC parameters.

  I know there are many books that have been written and solutions given for
the TC model. What I am looking for is a coiler who has actually performed
the 4th order calcs for his coil at the design stage and built and tested
the coil for comparison. Did Skeldon et al do this and did they use
empirical data? With this information why hasn't someone writen a TC
computer program using the 4th order differential equations or the classical
approximate solution? Would this require empirical data to make it complete?

  My server was not able to find your URL. Has anyone on the List been able
to download Antonio's Teslasim program? If so, have you used it to design,
build, and test a coil to see how it compares with the program?

  John Couture


<<<< Antonio's site at:

http://www.coe.ufrj.br/~acmq/links.html

Came up fine for me.  TeslaSim is at:

ftp://ftp.coe.ufrj.br/pub/Acmq/teslasim.zip

 - Terry >>>>




------------------------------------

At 07:13 PM 2/6/99 -0700, you wrote:
>Original Poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 
>
>Tesla List wrote:
>
>>   I agree that there are direct analogies between capacitors, inductors,
>> masses , and springs. I have been able to set up the 2nd order differential
>> equations for these parameters on a spreadsheet and print out the graphs
for
>> the single RCL circuit representing the TC primary or secondary circuits. I
>> overlooked the operating spark gap. However, I have never seen a solution
>> for the actual coupled TC primary and secondary circuits using the 4th
order
>> differential equations. I doubt that anyone has ever done this. I hope that
>> coilers will not refer me to books that are hard to find and do not show
the
>> proper information.
>
>The exact analytic solution for a 4th order system involves finding the
>roots of a 4th-order polynomial, to find the natural frequencies. This 
>is perfectly possible, but the expressions are rather complicated in the
>general case. 
>The classical approximate solution for the Tesla Coil model, assuming
>low-loss, can be found in the paper (a very readable paper):
>K. D. Skeldon, A.I. Grant, and S. A. Scott, "A high potential Tesla coil
>impulse generator for lecture demonstrations and science exhibitions,
>"American Journal of Physics, Vol. 65 (8), pp. 744-754, August 1997.
>The solution appears also in the book "Static and Dynamic Electricity",
>by W. R. Smythe (1939), with extensive discussion (a rather heavy
>reading), and in several other places.
>What is much simpler to do is to find a numerical solution. An
>exact numerical solution is relatively easy to obtain.
>And I can say again that it is implemented in my Teslasim program.
>(that also doesn't compute the mutual inductance...)
>Note that that analysis is applicable only while the primary gap is
>conducting, and models it as s simple linear resistor, what little
>difference makes if the losses are small.
>
>Antonio Carlos M. de Queiroz
>(For Teslasim, look at http://www.coe.ufrj.br/~acmq/links.html)