Re: K Quiz
Subject: Re: K Quiz
Date: Mon, 16 Jun 1997 19:33:29 -0700 (PDT)
From: "Edward V. Phillips" <ed-at-alumni.caltech.edu>
" The coupling coefficient should only
govern the relative amount of time that it takes to transfer the
primary's energy to the secondary. However, I suspect that, in practice,
it may indeed be more significant, since the secondary is not a simple
lumped parameter inductor. "
The first statement is true, but not the whole story. The
coupling coefficient also determines the two resonant frequencies
of the circuit. By picking the right value of k (there are an
infinite number, but only a few which really are important) you can
tune things so the current in the primary goes to zero as the current
at the time when all of the energy has been coupled to the secondar.
Secondar(y)! Under that condition all of the energy which was
originally stored in the primary capacitor has been transferred
to the secondary, and if the gap opens at that time you have the
best possible conditions.
I think you will find that with any significant amount
of top-loading capacitance (toroid) the difference from a lumped
circuit is small enough to ignore, especially since the secondary
Q drops dramatically when the streamers start.