Re: Tom Heiber <theiber-at-lonet.ca>

To: tesla-at-poodle.pupman-dot-com
Subject: Re: Tom Heiber <theiber-at-lonet.ca>
From: Tesla List <tesla-at-stic-dot-net>
Date: Fri, 30 May 1997 22:27:32 -0500
Approved: tesla-at-stic-dot-net
Subject: Re: Tom Heiber <theiber-at-lonet.ca>
  Date:  Fri, 30 May 1997 18:41:36 +0000
  From:  "John H. Couture" <couturejh-at-worldnet.att-dot-net>
    To:  Tesla List <tesla-at-pupman-dot-com>


At 07:08 AM 5/30/97 +0000, you wrote:
>    From:  Tom Heiber <theiber-at-lonet.ca>
>> Organization: Power Surge
>>          To:  tesla-at-pupman-dot-com
>> 
>> 
>> This is an equation I got from Bert Pool's file.
>> 
>>    
>> =======================================================================
>>     EQUATION 10: CAPACITANCE OF A TOROID
>>                                                     ___________________
>>                                                    /    2
>>          C =(1+ (0.2781 - d2/d1)) x  2.8  x      /  2 pi  (d1-d2)(d2/2)
>>                                                /   -------------------
>>                                             \/      4 pi
>> 
>> 
>>      C = capacitance in picofarads (+- 5% )
>>     d1 = outside diameter of toroid in inches
>>     d2 = diameter of cross section (cord) of toroid in inches
>> 
>>     Equation courtesy of Bert Pool
>>    
>> =======================================================================
>> 
>> 
>> CAN ANYONE help me solve for D1 as in D1=........
>> I have been trying to do this without any results (I suck at math)
>
>Turns out to be a bit of a horror.
>    Firstly, the original can be considerably simplified (assuming 
>the form above is correct):  
>
>   C = ( 0.695 - 2.5(d2/d1) ) x SQRT( d2(d1-d2) )
>
>As far as I've got with attempting to extract d1 (hopefully no 
>errors):
>
>(C^2)/d2 = 0.476d1 - 3.9d2 + 3.425(d2^2) + (d2^2)/d1 - (d2^3)/(d1^2)
>
>    I have reservations about all this anyway because it doesn't 
>factor in the proximity of the toroid to the resonator.
>
>FWIW,
>Malcolm
>
>---------------------------------------------

  All -

  An easy to use graph of theoretical sphere and toroid capacities is
shown
in the TCBA News Vol 16 #1 Jan '97. If you know the capacitance the
graph
will show you many combinations of toroids you can use and vice versa.
Tests
have indicated the actual capacitance on (proximity) the coil is about
75 to
80 percent of the theoretical capacitances on the graph. The graph is
also
shown in my Tesla Coil Notebook.

  With the JHCTES computer program you can find the exact sphere or
toroid
capacitance on the coil after it is built and tested and the actual
operating frequency determined. Of course, you can do the calcs yourself
if
you want to do it the hard way.

  If you want a copy of the graph I will sent you one if you send me a
SASE.

  John Couture
  10823 New Salem Point
  San Diego, CA 92126