RE: Help with calculating secondary self resonant freq?

["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>


The JHCTES Ver 3.3 program agrees with Ed's numbers.

Enter for secondary  1.1875, 1662.375, 143, 0.0, 0.0

Outputs 426.32, 4.54, 30.70

This program uses Wheeler and Medhurst equations. The outputs have been
found to agree with tests since the late 1980's. The program is on-line and
at

     www.mgte-dot-com

Click   Tesla, JHCTES, etc.

John Couture

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


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, April 02, 2003 10:43 PM
To: tesla-at-pupman-dot-com
Subject: Re: Help with calculating secondary self resonant freq?


Original poster: "Ed Phillips by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>

Tesla list wrote:
  >
  > Original poster: "Mercurus2000 by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <mercurus2000-at-cox-dot-net>
  >
  > Hello, I was curious, I wound a medium size coil for experimenting and I
  > was wondering if someone could help me calculate the frequency for the
  > coil, the coil winding is 11.625 inches high 1662.375 turns of 34 gauge
  > enamel wire and the diameter of the coil 2 3/8 wide on standard PVC, if
  > anyone could give me just a estimate withouth having a topload I would
  > greatly appreciate it and can verify my calculations.
  > Mercurus

	I just ran a calculation using a simple Basic program I wrote a number
of years ago.  (I think I entered your values correctly.)  Here's what I
get:

fr = 426.4 kHz
cd = 4.54 uufd
L = 30686 uh

This is a simple program using one of Wheeler's approximations for
inductance and a curve fit to Medhurst's data.  I have found that, at
least for the coils I've tested, it gives results within a couple of
percent, better than I expected when I wrote it.

	Be interesting to see what others get.

Ed