Re: [TCML] Calculating the C of multiple Spheres for a top load ?

[jhowson4@xxxxxxxxxxx]

Antonio, 

What did you end up doing for your 4 sphere approximation , 

I was attempting to use image charges, (3 per sphere,each on a line to the center of another sphere located at some radius less than the sphere radius.) to figure it out but with my senior project being due last week I did not have the time to look into it much aside from the casual thought. 



Thanks, 
John "Jay" Howson IV 

"Why thank you, I will be happy to take those electrons off your hands." 

----- Original Message -----
From: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx> 
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> 
Sent: Monday, February 27, 2012 9:11:12 PM 
Subject: Re: [TCML] Calculating the C of multiple Spheres for a top load ? 

On 26/2/2012 12:56, jeff mill wrote: 
> Hell again 
> I’m puzzled . If I plug in an 8” dia sphere in TM it comes up with 11.4pf, If I have four of them 4 X 11.4 =5.6pf I would think. Now the surface area of four of them when calculating, is equal to a 16” sphere but when I plug a 16” sphere into TM is only doubles and comes up with 22.7pf, not 45.6pf like I would think. Can anyone sheds some light on this ? Which is correct ? 
> 
> Thanks JM 
The distributed capacitance of an isolated object is proportional to its 
size, not to its area. The capacitance of four spheres (in a square 
configuration) is difficult to calculate exactly, but is surely smaller 
than the capacitance of a toroid enclosing them. A toroid having small 
diameter of 8" and a large diameter of, say, 24" (0.61 x 0.20 m) has 
27.5 pF of capacitance. Four spheres far apart would have 4 x 11.30 = 
45.2 pF. 
(Now I have to find a way to calculate the exact capacitance of four 
spheres...) 
A first approximation for the case above results in 11.30 x 2.04383 = 
20.0953 pF. 
With the spheres touching, 11.30 x 1.69955 = 19.2050 pF. 

Antonio Carlos M. de Queiroz 



_______________________________________________ 
Tesla mailing list 
Tesla@xxxxxxxxxx 
http://www.pupman.com/mailman/listinfo/tesla 
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla