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: Sun, 06 Sep 1998 20:00:27 -0600
Approved: terryf-at-verinet-dot-com

  Reinhard -

  The spark characteristics such as brilliant white core are dependent on
the current but only the voltage determines the path of the spark length.
Of course, the properties of the air or gas will also affect the spark
length and appearence.

  I believe what Brent Turner was referring to was the fact that the
calculated capacitance of the toroid or sphere is not the capacitance that
the toroid or sphere has when placed on the Tesla coil. The presence of the
coil and other objects lowers the capacitance about 15% to 30%. This is one
of the reasons why the TC has to be tweaked after it is properly designed
and built.

  There is no way to determine the effective toroid capacity on the TC at
the design stage. However, in the information with my books I show a method
of finding the exact effective capacitance of the toroid or sphere on the
TC after it is built and tested and using the JHCTES computer program. 

  John Couture

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

At 07:16 AM 9/5/98 -0600, you wrote:
>Original Poster: RWB355-at-aol-dot-com 
>
> Original Poster: "John H. Couture" <couturejh-at-worldnet.att-dot-net> 
>SNIP
>   These equations indicate the output voltage (Vs) or spark length would
> decrease, not increase, if the Cs (toroid capacitance) was increased.
>    Any comments regarding this apparent contradiction with theory? How would
> you or do you determine the optimum toroid size for a particular TC design?
> It is obvious that changing the toroid size affects the spark length as
> proven by tests.
> 
>Hi John,
>
> Here are my 2 (s)cents worth.
> I would suppose increased spark length is not only dependent on the output
>voltage but also largerly depends on the output current, which DOES increase
>when you increase the total capacitance.
>There has also been a lot of controversion about  (Ctotal = Csec+Ctopload).
>You can´t really just add Ctopload to Csec to get the total capacitance. I
>have seen equations where only 75 % of Csec+Ctopload are used as the total
>capacitance.
>
>Brent Turner drew a nice diagram which clearly shows that the equation 
>Ctotal=Csec+Ctopload does not really hold true. For a look at the average
>frequency 
>it comes close enough however.
>
>I posted it on my webpage:
>www.geocities-dot-com/CapeCanaveral/Launchpad/4902/sec.gif
>
>Sorry, this is the only file on my webpage at the time because I simply don´t
>get around to shaping it up
>
>coiler greets from germany,
>Reinhard
>
>
>