Re: K Factor & Mutual Inductance

To: tesla-at-poodle.pupman-dot-com
Subject: Re: K Factor & Mutual Inductance
From: Tesla List <tesla-at-stic-dot-net>
Date: Mon, 07 Apr 1997 23:17:59 -0500
Approved: tesla-at-stic-dot-net
Subject: 
        Re: K Factor & Mutual Inductance
  Date: 
        Mon, 7 Apr 1997 20:58:07 -0400 (EDT)
  From: 
        richard hull <rhull-at-richmond.infi-dot-net>
    To: 
        Tesla List <tesla-at-poodle.pupman-dot-com>


At 07:58 PM 4/6/97 -0500, you wrote:
>Subject: 
>        Re: K Factor & Mutual Inductance
>  Date: 
>        Mon, 7 Apr 1997 04:57:32 -0700
>  From: 
>        "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
>    To: 
>        "Tesla List" <tesla-at-poodle.pupman-dot-com>
>
>
>To: John Couture
>
>Hi John:
>
>We normally think of coeff. coupling being independent of system power,
>ie,
>if you ignore the effects of additional electric field capacitance above
>the sec. coil (usually on 5% or less anyway) then the coeff. coupling
>measurements should be the same with a sig. generator and scope vs. a
>powered up system.  Does your equations somehow tie "power" into the
>coeff.
>coupling equation??  
>
>I know the relationship between mutual inductance, coeff. coupling, and
>Q,
>but was wondering how power fits into the system with regard to
>calculations?  Any comments greatly appreciated in this area.
>
>We normally tune up systems using a sig. generator (vacuum tube type for
>higher output) and scope, and then make an adjustment for actually power
>up
>operation.  There seems to be a direct linear relationship between these
>two primary tap positions.  A small extrapolation is usually necessary
>for
>high power systems operating over 5 KVA.
>
>We plan to do some more direct research in this area this summer and try
>to
>develop an exact difference so as to develop a simple equation or simple
>ratio/proportion which can be applied to most coil systems.  Richard's
>systems with high coeff. coupling might respond differently.
>
>Any comments -- John or Rich H., et al   -- on your thoughts and
>observations.
>
>DR.RESONANCE-at-next-wave-dot-net


 Guys,

I find that the coefficient of coupling is far more important in larger
systems where a lot of power is processed and equations and even scoping
fail consistently to genrate an "optimum tune point".  In the kind of 2
coil
systems I normally build, the coupling coefficient is up around K=.25
(Nemesis).

  The top hats are huge also, being over two times the coil length in
diameter.  For the maggies, it is 4 times the coil length in diameter,
(as
on maggey 11-E.) these generate a large capacitively active and varying
field.  Add to this electrostatic shading in this variable environment.
With all this, I don't wonder at the failure of the classic radio
formulations and normal tuning procedures to fall a bit short.  
Frankly, I
really don't care either, as it always a cut and try operation from the
get
go in research where convention and accepted design are deliberately
cast aside.

  I have a sign over my lab door... "research is what I'm doing when I
don't
know what I'm doing."

As Dr. Peter Graneau wrote in his book Newton vs. Einstein,
(paraphrased) 

One must not think that theory kept pace with new inventions (during the
mid
19th century)  The theoretical physicists were often hard pressed to
provide
explanations for actual working inventions!

With this in mind, I'll get it up and running and let the mathematically
inclined duke in out over the physics.  As an engineer, I know the
theory,
but I won't let it limit or hamstring me.  Only nature and the laws it
obeys
can do that.  Whether all theory is in harmony with nature is always up
for
discussion in my book.  Discussion always follows the doing at the end
of
the day.

Richard Hull, TCBOR