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Re: K Factor & Mutual Inductance
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
----------
> From: Tesla List <tesla-at-poodle.pupman-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: Re: K Factor & Mutual Inductance
> Date: Saturday,April 05,1997 5:42 PM
>
> Subject:
> Re: K Factor & Mutual Inductance
> Date:
> Sat, 5 Apr 1997 07:35:08 +0000
> From:
> "John H. Couture" <couturejh-at-worldnet.att-dot-net>
> To:
> Tesla List <tesla-at-pupman-dot-com>
>
>
> At 05:24 AM 4/3/97 +0000, you wrote:
> >Subject:
> > Re: K Factor & Mutual Inductance
> > Date:
> > Wed, 2 Apr 1997 18:01:13 -0800 (PST)
> > From:
> > "Edward V. Phillips" <ed-at-alumni.caltech.edu>
> > To:
> > tesla-at-pupman-dot-com
> >
> >
> >" is found the K Factor can be found by the equation
> >> K Factor = Lm/(sqrt(LpLs))
> >> where Lp and Ls are the inductances of the primary and secondary
coils.
> >
> >That equation is good for any coil - air-cored, iron cored or
> >whatever? There are no conditions stated by Terman or anyone else to
> >my knowledge (except JHC perhaps ;)
> >
> >> Note that the K Factor or coupling is not only dependent on the
physical
> >> location of the coils but also on several other parameters such as
> >> resonant
> >> frequency, Q Factor, log decrement, etc.
> >
> >Where is the frequency dependence in that equation? Lp? Ls? M? k? I've
> >not observed any frequency dependence in Lp or Ls from DC to TC
> >frequencies in all the measurements I've done. So it must be in k or
> >M, right? But what defines either of those? Is the number of flux
> >linkages between two coils frequency dependent? Why?"
> > The coupling factor is independent of frequency, Q, etc.
> >the definition is exact (for coils inductively coupled coils).
> >Ed
> >
> ---------------------------------------------------
>
> Ed -
>
> The TC parameters are tied together by the impedences.
>
> K = Xm/sqrt(XpXs) Xm = 6.283 FLm
>
> Xp = 6.283 FLp Xs = 6.283 FLs
>
> Q = Xs/Rs = 6.283 FLs etc.
>
> When a change is made in a TC parameter the impedence changes which
> affects many other parameter impedences in the JHCTES computer program.
> The
> changes are necesary because the program keeps the system in tune.
> Otherwise
> you would end up with a system that was not in tune after the change.
>
> John Couture
> >