RE: Calculating Capacitance of solid disk

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "John H. Couture by way of Terry Fritz <teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Bart -

The 140.08 pf can't possibly be the correct capacitance for a 4 inch disk.
My estimate is about
   3.98456 pf capacitance.

John Couture

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


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, March 09, 2003 1:32 PM
To: tesla-at-pupman-dot-com
Subject: Re: Calculating Capacitance of solid disk


Original poster: "Barton B. Anderson by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <classictesla-at-netzero-dot-com>

Hi Dan,

This is a nice function of Fantc. It can perform analysis of object
capacitance for toroids, spheres, spheroids, discs, and cylinders (up to 10
each of wanted). In this case, I simply computed the 4" disk capacitance.
Here's the output at a detail 3 setting.

Computing ..... please wait
System or Object Capacitance: 140.08 pF
Run CompleteTime elapsed: 2.1 secs

To run an objects capacitance, input the dimensions. For your inquiry, my
inputs were:
disc inside diam. = 0
disc outside diam. = 4
disc height = 0

Then, check the "Disc" checkbox as the system component (only one needed),
and press the "Run Capacitance Analysis" button.
http://www.classictesla-dot-com/fantc/fantc.html

Take care,
Bart

Tesla list wrote:

 >Original poster: "Mccauley, Daniel H by way of Terry Fritz
 ><teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>
 >
 >
 >Instead of a toroid, I'm going to use an aluminum disk top plate which I'll
 >lathe to have nice radius outside edge.
 >
 >Anyone know how to calculate the capacitance of a disk like this?  I would
 >think it would be approximately close to
 >the standard toroid capacitance formula.
 >
 >I know I could measure it directly using another coil, but I'll be
designing
 >and winding my secondary before I machine this
 >disk so I want to get a good approximation of the disk.  The dimensions
will
 >roughly be about 4" diameter and 0.5" in height.
 >
 >Thanks
 >
 >The Captain
 >
 >
 >
 >