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Re: Arc Impedance Study - Computer Models

At 09:03 PM 10/10/98 -0600, you wrote:
>to: Terry
>
>snip
>
>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.
>

	I feel the distributed capacitance on a secondary is very different that
the distributed capacitance on a transmission line.  A line has unifiorm
capacitance to ground along it's length.  A secondary's capacitance is a
large space charge region that is interacting with the toroid and all the
coil windings.  For disruptive coils, the top and bottom currents are also
exactly in phase indicating that the typical transmission line delays are
not present.  However, there is no doubt that the magnitude of the current
at the top of the coil is less than the magnitude of the current at the
base due to energy being stored in the distributed capacitance of the coil.
 I have also not seen any standing wave effects on disruptive coils in
operation.  Of course, when you hook up a sine generator to the base of a
coil, all kinds of standing waves are formed with all kinds of harmonics.
However, in fast rise time disruptive operation, these effects do not seem
to exists.  Now that I have much better equipment I will study all this more.
	I suspect that the sudden discharge of the distributed capacitance along a
coil is responsible for the racing arcs seen at high couplings and such.
More work to do there.

>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.  

Rotary gaps do not seem to quench at all in my tests.  In the case of no
quenching, the secondary and primary stay coupled and any Q effects are
damped.  Tuning is not very critical in disruptive coils.  The system is
always in transition and there is not a chance for much resonant build up
to occur.  This is demonstrated by the primary inductance test in my other
post.

>
>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.
>

All the work I do is with disruptive systems where VSWR effects do not seem
to exist to any degree.  However, in magnifier and CW coils the situation
may be very different.  I feel there may be a giant difference in the way
disruptive and CW systems operate.  Just as there is a large differnce in
the way static and rotary gaps operate.  Unfortunately, I don't have access
to a magnifier or CW system to probe :-(

	Terry 


>For what it's worth,  . . . . .
>
>DR.RESONANCE-at-next-wave-dot-net
>
>
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