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Re: Mutual Inductance & K Factor



Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi John -

Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
>
> Bart -
>
> For some reason I keep messing up the specs on this coil. Anyhow it will be
> interesting to find out what the tests show.
>
> I do not understand how you arrived at the 65.3 for the top terminal
> reduction. This parameter appears to affect some outputs including the
> resonant frequency but not the mutual inductance or the K Factor.
>
> John Couture

The value is derived from ETesla6. I put the secondary specs into ETesla6,
keeping the walls and
ceiling at a distance to make their effect as negligible as possible. The
toroid input is with the
toroid bottom edge even with the top secondary winding. I put the bottom of
the coil at 30" off the
ground (just an average input there). ETesla6 pumps out Fres.

I then change the top loads capacitance until JavaTC matches ETesla6 Fres
using the % Reduction input.
If I want to "reduce" the top capacitance by 10%, I put the value 10 in the
input box.

ETesla6 should actually be checked as a bare coil against programs as well
as with top load. I only
used the top load at the time. I don't know actual values of Nolan's
ceiling and walls, etc.., so it's
just an approximation to get into the ballpark.

The 65% sets uneasy with me as well, so I just ran it again and I'm getting
44.3%. I must have had an
incorrect input in ETesla6 during that particular run through (this changes
the primary tap less than
1/2 turn). Yet this is still a significant drop in effective top
capacitance which I found true in
each run through. It's an interesting coil due to it's size, small
inductance, 2.8 major/minor ratio
in the toroid. We should look at more of these geometry's. I really should
build one.

Regarding Mutual Inductance and K. Neither is made to change with
frequency. If there is significant
change with frequency that would justify pulling Fres as a factor, I've yet
to see or be informed of
that.

Take care,
Bart