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Re: Arc Impedance Study - Computer Models

Hi DC, all,

> Original Poster: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net> 
> 
> to: Terry
> 
> Nice post with clean, clear data.  Your 1" sec elevation is very close to
> my usual recommendations of 1 to 1 1/2 inches above the plane of the pri
> coil for bottom turn of sec coil.  Any coiler running a 20 to 24 inch dia
> coil will find 7 to 9 inch elevation of sec coil above the primary plane
> works best.
> 
> Malcolm also recently posted some confusion regarding, "the resonator
> behaves as a lumped circuit exhibiting a uniform current throughout its
> windings and wondered how the current could be the same at both the top and
> bottom with no topload?"  The answer is --- it isn't the same.  Without a
> large topload their is distributed not lumped capacitance throughout the
> length of the sec coil and due to this distributed capacitance the coil
> acts more like a transmission line.  The sec coil will support a variety of
> harmonics (some quite strong).  When a large lumped capacitance is added to
> the top the harmonics are supressed and the sec does not have even current
> at both top and bottom.

Sorry, I didn't intend to be confusing. I was questioning the notion 
that uniform secondary current could exist in a coil with no topload 
*when the gap is firing* as is claimed in some quarters. I maintain 
it cannot simply because there is virtually no loading on the top 
turns. In fact, the top turns become the terminating capacitance in 
my view if no other topload exists. Yes? 

> Once corona ruptures the air the sec coil becomes de-tuned and its Q factor
> quickly lowers.  An equilibrium is established when the spark load and
> internal secondary losses are equal to the power being transferred from the
> primary.  When the primary power level becomes less than the sec spark load
> plus internal secondary losses, the primary starts to run out of power
> power and rings down -- hence quenching can occur.  As long as pri power is
> greater than sec power during the transfer process, then spark gap
> (primary) quenching will not occur.  
> 
> Ringup is uniform with even volts/turn across the sec inductor with a large
> topload.  
> 
> Malcolm also discussed the VSWR vs. Q factor (1.3 x full ring-up value). 
> The term VSWR does apply to transmission line coils with little or small
> topload, however, VSWR is not relavent to modern design with large topload
> capacitive values.  VSWR is a transmission line term and is not important
> with large toploads.  An interesting overlapping "gray" area does exist
> with systems operating with a medium size topload --- that is somewhere
> between small topload and large topload.  This "gray" area is somewhat of a
> balance between these two processes and explains clearly why some
> investigators are obtaining strange results in their measurements.  These
> measured values like Lou Balint is obtaining will not apply to resonators
> and magnifiers with large top loads such as Rich Hull and TCBOR have
> constructed.  Lou's work would apply more to small systems without large
> toploads and may give false impressions if this data is applied to a
> spark-excited system with large toploads.  Caution is advised in this area
> of interpretation.

Quite so. Well, I haven't seen this in a myriad of tests I've done and
it doesn't appear to happen in coils with no toploads either. No 
confusion intended. Just wanting to get it sorted out for once and 
for all.

Thanks,
Malcolm