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Re: overquenching (was light dimmer...)



In a message dated 99-03-29 21:12:14 EST, you write:

<<snip>From a holistic standpoint I can't see any difference between unsteady
> or
> erratic firing and overquenching.  Both result from the performance
> limitations of certain types of gaps in different systems-- and so whether
> a series rotary isn't ideal for TC work because it overquenches, or because
> it doesn't allow for a complete firing is in some ways beside the point.
> Here someone else ought to take over-- since I have exhausted my meager
> resources of theoretical and practical knowledge!
>                 --Mike
  >>

Mike, all,

It is true that both situations if they occurred would degrade the
performance of a TC.  I always assume that folks want to 
understand the reasons why their coil is performing the way it is.
I know that quite a few coilers on the list are very interested in the
theories of TC operation, and have a strong desire to understand
their operation more fully.  It is when these issues are not addressed,
and fully explored, that myths arise.  In both static gaps and series
rotary gaps, unsteady firing occurs if the gap spacings are too wide
for the voltage available, or if there is too much of an air blast.  In
both types of gaps, the unsteady firing can be cured by reducing the
number of gap electrodes, or the electrode spacing.  Generally the
dwell (mechanical time duration of electrode overlap) in a rotary is
much longer than the first notch ring-down time.  This tends to make
overquenching impossible.  It is conceivable that in a TC running
at an extremely low frequency of 20kHz or less, the mechanical
dwell might be able to match the ringdown time, if the electrodes
were extremely narrow, and the rpm extremely high.  Still, there is
some question as to whether it would truly overquench to any 
meaningful degree.

John Freau