Re........ Measuring Coupling Coefficients

From: 	terryf-at-verinet-dot-com[SMTP:terryf-at-verinet-dot-com]
Sent: 	Thursday, December 11, 1997 10:13 PM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: Re........  Measuring Coupling Coefficients

Hi Bart,

Snips are many.........

>From: 	Barton B. Anderson[SMTP:mopar-at-mn.uswest-dot-net]

>> > -------------------------------------------------------- snip
>> >> The equation ( K = >1/sqrt(QpQs) ) will predict a K of 0.0527 but does not
>> > take into account that the two coils are separated by 150 feet and thus
have a K
>> of  zero.
>ok, I'm confused. I've been reading these posts and am become more confused
by the
>moment. In the above statement, what does "separated by 150 feet" mean? Is
this just
>an arbitrary view point? an exaggeration, a "what if"?

I meant to point out that a very critical element (the separation distance
of the primary and secondary inductors) did not seem to be considered in
this equation and therefore questioned it's validity.  The variables Qp and
Qs are not dependent on the separation distance of the coils but the
resulting number K definitely is.  Something seems to be very wrong.


My testing suggests that measurements of the mutual inductance at 60 HZ and
350KHz are the same.  I too thought the higher frequencies would give
different results but that was not the case.  Others have confirmed this
"frequency independence" of the mutual inductance.  There are those that
measure the mutual inductance by looking at waveforms generated by the Tesla
coil and sometimes to claim that the mutual inductance is dependant on
frequency but I feel other factors are at work in these cases.  I originally
wanted a rock solid and provable way to determine the mutual inductance for
use in classical loose-coupled transformer models and found it.  The thread
has gone on....... beyond my original intent :-|.