Re: Magnifier first light

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <teslalist-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
 >
 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

 > COOL!!  You beat me to it :o))

But my C2 capacitor was very bad. Your realization will be more useful
as a test of the concept.

 > There are two schools of thought here.  Either the streamer length is
 > dependant on power alone such that John's spark length formula will still
 > hold true.  Or, that the much higher voltages of the magnifier will push
 > further streamers even if the power is held constant.  Past evidence
 > supports both.  No solid data to prove or disprove either.  Hopefully, we
 > will fix that ;-)

The old questions of exactly what we want in the energy transfer to the
resonator, apart from the average power, controlled by the primary
circuit. How much voltage? How fast? How much topload capacitance?
What quality factor in the resonator?

 > Yes!  And that is a bad place to be having a lot of series resistance.  My
 > coil will have a very low loss (hopefully) C2 so we'll see if that makes a
 > difference.  Capacitors getting hot deep in the power transfer section
 > could have a dramatic effect on streamer length!

Flat plate capacitors without special insulation will always show
corona around the plates, if not between the plates and the dielectric,
wasting energy. I could put more capacitors in series, or design
them so the electric field never exceeds the breakdown field in air.
This would be difficult. I could make a capacitor totally encapsulated
in solid dielectric (hot glue, for example). With everything
optimized I would end with a homemade HV MMC...

 > That is interesting!  No other magnifiers have a separate C2.  Sort of
 > suggesting C2 is not needed.  However, maybe the C2 losses are so great it
 > is better off without it.  Hard to say which.  At least none of the
 > observed performance is worse than a two coil system.

The observation of the waveforms with the lumped C2 disconnected
shows that there is still significant C2 in the system. My secondary
coil has more Medhurst capacitance than the resonator, and the
resonator "seen from below" has to show some capacitance too (I
am assuming Medhurst capacitance there too). I will make some
mesurements to verify this. It's evident that a large magnifier
may have enough distributed capacitance to dispense with a
lumped C2.

 > If quenching is good without C2 and no quenching with C2, that could make a
 > dramatic difference too.

This apparently happens.

 > Ok!  The L2 to C3 wire is always covered with corona.  The base of L3 is a
 > logical place too.  I am a bit surprised that the top of L2 is not a
 > problem but happy to hear if it is not.  Corona ring time ;-)

There was some corona at the top of L2 too, specially at the screw
ending the coil. The problem at the base of L3 was sparking between
the bottom turn and the screws that hold the two plastic beads that
hold the coil. Little sparks through the top holes of the beads:
http://www.coe.ufrj.br/~acmq/tesla/mres4br.jpg

 > Looking forward ;-))  I wish so much that mine was going!!!  This sounds
 > like way too much fun!!!

I will improve the fixation of the primary with the secondary, and
adjust
it precisely for the required k. I will also see what can I do about
C2. Maybe study an MMC construction.

Antonio Carlos M. de Queiroz