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Re: "De-coupling" coefficient?



Original poster: "Jolyon Vater Cox by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

I am interested to know how k,the coupling coefficient, affects the value of
the load impedance referred back to the primary across the turns ratio when
the transformer is not "ideal".

If the term k represents the fraction of the total flux which is common to
both windings (the coupled flux)
there must be another term  say, l, for the remaining fraction which
represents the flux which is not common to either winding (the leakage
flux).
Since k is the coupling coefficient  would it not be natural for l the be
termed the de-coupling coefficient?

Speaking of a mechanical analogy (perhaps not strictly accurate) is it not
possible to view transformers as "gearboxes" for electrical energy
the ideal transformer being akin to a ideal gearbox with unity coupling i.e
zero slippage between the gear teeth whereas  real transformers and
gearboxes are less than ideal exhibiting finite slippage?

And if it is permissible to speak of a de-coupling coefficient, would it not
be possible for the new term to be be used to derive the value of leakage
inductance from the values of the primary and secondary inductances.

Jolyon.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, July 02, 2003 12:34 AM
Subject: Re: "De-coupling" coefficient?


 > Original poster: "Malcolm Watts by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
 >
 > On 30 Jun 2003, at 17:10, Tesla list wrote:
 >
 >  > Original poster: "Jolyon Vater Cox by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>
 >  >
 >  > Malcolm,
 >  > My mistake -the RHS of the equation was missing a primary voltage
 >  > term -without which it is of course, complete nonsense.
 >  >
 >  > It should have been
 >  >
 >  > Vsec = Vprim.k.sqrt(Lsec/Lprim)
 >
 > It still doesn't hold. It is basically describing output in terms of
 > turns ratio (which is OK) plus k (which is not OK without considering
 > loading). I am curious to know what the point of all these questions
 > is.
 >
 > Malcolm
 >
 >
 >