Re: Tesla Coil toroid Size

To: tesla-at-pupman-dot-com
Subject: Re: Tesla Coil toroid Size
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Thu, 10 Sep 1998 17:07:39 -0600
Approved: terryf-at-verinet-dot-com
At 10:18 PM 9/9/98 -0600, you wrote:
>Original Poster: "Barton B. Anderson" <mopar-at-uswest-dot-net> 
>
>Tesla List wrote:
>> 
>> Original Poster: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>> 
>> At 07:59 PM 9/8/98 -0600, you wrote:
>> >Original Poster: "Barton B. Anderson" <mopar-at-uswest-dot-net>
>> >
>> ><SNIP>
>> >
>> >> Original Poster: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>
>> I believe the long or short sparks depend on the potential available.
>> Obviously the potential is varying with typical TC operation. This is why I
>> recommend controlled sparks. This pins down the potential and the spark
>> length and greatly simplifies analysis.
>
>I'm not so sure the long and short sparks depend on the
>available potential (at least the way I think of
>potential). Could you expand on your hypothesis here? I
>believe the long and short sparks depend on the energy
>available/released when the potential reaches breakout,
>or the pressure of the breakout.
---------------
 I think we are referring to two different types of processes here. I am
referring to the "potential" for initiating the spark. You are referring to
the "energy" required for a series of sparks.
---------------- 
>> I believe that initiating a spark and the driving factor for the spark are
>> two different aspects of spark formation.
>
>Agreed! Initiating a spark we are familiar with. Driving
>a spark is the spark-length affect of which we observe,
>but cannot yet explain mathematically. This drive must
>be understood to know how a toroids capacitance/size
>plays this significant role in spark-length.
---------------
 Note that the potential required to "initiate" the spark is not the same
as the potential required to maintain (drive) the spark. As I have
mentioned in past posts the initiating potential is for a very short time
and then reduces
to a potential characteristic of an arc.
--------------
>> The spark represents energy. When the spark lengthens, it could mean a gain
>> in energy.
>
>This is an interesting hypothesis. If Ctop corresponds
>to energy gain (either in watts or efficiency), I wonder
>if spark formation time changes with energy potential? I
>might be way off on that one, but it seems as I turn up
>the juice, the spark channels are not only longer,
>brighter, and loader, but faster (for the same bps). I
>may be way out on a limb, but it does make me wonder.
>
>Bart
-------------
 I am referring to a "spark" which represents energy. You are referring to
a "Ctop" that represents a form of capacitance which can store energy. I do
not understand what you mean by "Ctop corresponds to energy gain".

 I agree that when you "turn up the juice the spark channel can be not only
longer, etc, etc". This is as you should expect because you are adding more
electrical energy to the TC system and should get more output. However, as
you continue to turn up the juice you will reach a point where the
increment of energy input is equal to the increment of energy loss (from my
book) so there will be no further increase in the spark channel. This
"point of no return" has been experienced by several coilers who appeared
confused by the results.

 The "point of no return" is a mandatory consideration for coilers who are
developing TC computer programs that coordinate all of the parameters into
one program like the JHCTES program. If the coiler fails to take this into
consideration he will build a coil that will spark over and be damaged.

 The JHCTES program controls this possible type of faulty design by
recommending default values when changes are made. The default values are
based on empirical data from my tests and the tests of other coilers.  

  John Couture