Tesla Coil Optimun Parameters

From:  John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
Sent:  Sunday, May 31, 1998 8:12 PM
To:  Tesla List
Subject:  Re: Tesla Coil Optimun Parameters 

  Terry -

  Empirical does mean as you indicated. I should have said that Tesla coil
design is based on both theory and empirical data obtained from experiments.

  The list that you show of what can be found by calculation or computer
simulation is what the JHCTES program can do. I started with a menu like
other programs available today. However, I realized that with the menu type
of program  making a change in one of the menu parameters required changes
in other menu parameters that could lead to design errors. To avoid these
errors I combined and coordinated everything into one comprehensive program
and called it the JHCTES Tesla Coil computer program. 

  The JHCTES program starts with a watts input, does the calculations for 46
TC parameters, and produces an output of spark length. No other program
available today can do this much TC designing at one time. It has been well
received by coilers. 

  As for eventually finding all of the TC parameters theoretically, that
depends on how you define theoretical equations. For example, Ohm's law  V =
R x I  is a theoretical equation (why?) but the resistance equation   R =
pL/A  is not a theoretical equation. The resistance factor "p" of a material
can only be found by tests. There are many other TC parameters of this nature,

  Thank you for the favorable comments regarding my books. They are still
selling after several years so other coilers share your feelings about them.
I have always believed and so did Tesla that the Tesla coil was a
transformer and did not operate according to 1/4 wave theory. Tesla coils
use magnetic circuits. Quarter wave theory does not.

  John Couture


At 11:27 PM 5/28/98 -0500, you wrote:
>From:  terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
>Sent:  Thursday, May 28, 1998 11:53 AM
>To:  tesla-at-pupman-dot-com
>Subject:  Re: Tesla Coil Optimun Parameters (was Wire length,resonance,  Q)
>        As one who lives in both the theoretical and practical world of
>Tesla coils, I must disagree.  
>First your statement "Tesla coil design is empirical meaning both theory and
>test results are required."  My dictionary defines empirical as "relying or
>based solely on experiment and observation rather than on scientific
>Empirical observations are collected and charted as a predictor when one has
>no idea as to the underlying principles involved.  I submit that there a few
>things we cannot predict about Tesla coils by calculation based on
>principles.  The few remaining "mysteries" are being solved very quickly and
>will soon be understood.  The following is a list of what can be found by
>calculation or computer simulation to very good accuracy.
>Primary coil inductance. - Wheeler's formula is based on empirical data but
>modern computer simulations can find the same numbers using known principles
>Secondary coil inductance. - Wheeler's formula is based on empirical data
>but modern computer simulations can find the same numbers using known
>Secondary coil self capacitance. - Oops! That one is still based on
>empirical data :-)  I bet it won't be for long.
>Coupling coefficient. - This solution has not yet been publicly released.
>Primary resonant frequency.
>Secondary resonant frequency.
>All neon transformer and control circuit parameters.
>All primary currents and voltages as a function of time.
>All secondary currents and voltages as a function of time.
>Basic spark gap operation.
>Electrostatic fields and breakdown. - Can be modeled by computer although
>few coilers do.
>Here are the remaining things to be discovered:
>The exact nature of the self capacitance.  This will be solved soon.
>Spark gap quenching principles. - This is probably months away from being
>The exact nature of how the output sparks affect the system.
>The impedance that Tesla coils need to drive to get good sparks.
>The dynamic impedance of the output sparks.
>        We are very close to being able to design Tesla coils "on paper" to
>produce the sparks we want efficiently.  I believe, within a year or so, the
>last remaining problems will be pretty much solved.  When they are, a
>computer could build and test more coils overnight virtually than we all
>could build in our lifetimes.  BTW my latest models use 14th order
>differential equations.  Of course, the computer does all the work but those
>equations could be printed out with a few days work and a ream of paper. :-)
>        I certainly do not mean to disregard the excellent work you and
>others have done in collecting Tesla coil data.  For a long time it was all
>we had.  However, the "era of mystery" surrounding Tesla coils is quickly
>coming to an end.  We have, after all, been working on it for almost 100
>years now!
>BTW  Now that the theory of standing waves (1/4 waves) in Tesla coils is
>falling apart.  I couldn't help noticing that your series of books are the
>only ones I have that don't have 1/4 wave theory all through them.  I'll
>keep yours! :-)
>        I hate to think how many countless days have gone into trying to
>figure out why Tesla coils don't match those theories well.  I, like most
>others on this list, struggled for years on standing wave theory and never
>could figure out why it never was quite right for Tesla coils.  At least
>Tesla, who started it, had the same fun we all did with it. :-)  
>        Terry Fritz
>        or
>>From:  John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
>>  Jim, All -
>>  Determining the optimum parameters for a Tesla coil is certainly a
>>challenge. But why do it the hard (or impossible) way? The Corum's in their
>>writings have shown the fourth order differential equations for Tesla coils.
>>But this is a long way from ending up with a spark length output.

---------------------------------------   big snip