RE: Mutual inductance and K factor

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-telocity-dot-com>


Weazle -

The equation you used apparently is not in the programs Terry has listed
below. Where did you find this equation? Your calcs are correct. It is the
equation that is incorrect.

 I ran Mark's example thru the JHCTES Ver 3.3 with the following results

                       Ver 3.3      Mark
  Mutual Inductance    569.310     742.900
  K Factor               0.159       0.203

It appers that Mark's K Factor may be too tight or the Ver 3.3 is too loose.
When I checked Paul's examples a year ago his program and the Ver 3.3
appeared to agree closely for some coils. These two programs are very
difficult to use and I have checked only the examples so the comparisons are
preliminary. Have any coilers used these programs and compared them with
tests of their coils for the mutual inductance and the K Factor?

It looks like we are going to have to wait until you get a chance to do the
test I showed. The result will also have to be verified by the operating
frequency and K Factor tests I mentioned. I said that testing Tesla coils to
check TC programs is not easy. In fact I do not believe any coiler has ever
done a complete job. It is just too time consuming.

John Couture

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

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, October 24, 2001 4:26 PM
To: tesla-at-pupman-dot-com
Subject: RE: Mutual inductance and K factor


Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi John,

I trust you are familiar with the actual measurment since I think it
basically comes from you book :-))

The computer calculation is actually from Dr. Rzeszotarski.  The file and
an explanation are at:

http://hot-streamer-dot-com/TeslaCoils/Programs/MANDKV31.PDF
http://hot-streamer-dot-com/TeslaCoils/Programs/MANDKV31.ZIP

Paul Nicholson also computes coupling to a high accuracy for his TSSP
project.  Paul's source code is available (UNIX) for those that wish to
dive into it.

http://www.abelian.demon.co.uk/tssp/

Cheers,

	Terry

At 04:40 PM 10/24/2001 -0700, you wrote:
>
>Weazle -
>
>Thank you for sending me the test data from your coil. I am aware of
Terry's
>method for finding the mutual inductance but I am not very familiar with
the
>typical calculations. My notes on his method are buried somewhere in moving
>boxes and I do not have his address for the test.
>
>Your caculations appear to be incorrect in that the mutual inductance
should
>reduce instead of increase when the secondary is raised. Also, are your
>coils pri to sec distance (1.0) and the pri inside radius (3.05) and
outside
>radius (7.55) of the used turns agreeing with the program outputs? I hope
>that you can soon test your coil with my method which requires no
>calculations by the user. With the proper amps (2.65 or 3.18) in the
ammeter
>you only have to read the mutual inductance uh from the DVM meter.
>
>The program shows a mutual inductance of 83.57 uh (you show 32.36) for zero
>inches distance of the sec above the pri and 66.15 uh (you show 42.97) for
>1.0 " distance. The 32.36 to 42.97 should be a decrease not an increase in
>mutual inductance. The K Factor of .075 to .100 should also be a decrease.
>
>If Terry would give me the address for his method I can determine what the
>calcs should be. Thanks Terry.
>
>John Couture
>
>---------------------------