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NEW TOROID TESTING

 * Original msg to: Esondrmn-at-aol-dot-com

Quoting Ed Sonderman:

 ES> I fired up my new 40.0" discharger last night.  The tune on  
 ES> the primary changed from 11.75 turns to 13.0.  Looks like I  
 ES> still did not make it large enough.  Maybe I will try the    
 ES> 33.0" toroid stacked on top of the new one. 

I stack toriods all of the time, try putting the smaller toriod
below the larger. The number of primary turns is right in the
"sweet zone" between 12-15 turns. If you want the extra primary
turns in use, you will have to wind an 8" coil or use a fatter
cross section in the torus.
 
 ES> It did make a major difference in power output.  I would     
 ES> guess that it is putting out 20% more power.  This is with   
 ES> the same power in to the pig of just under 4,000 watts.  I   
 ES> now get multiple, many forked simultaneous discharges.  Very 
 ES> hot and very long.  I can't even tell you how long, I would  
 ES> guess over 5.0 feet.  They are hitting everything in the     
 ES> basement.  Even the wood floor joists have become an         
 ES> attractive target. It is scary - I love it. Now I wonder if  
 ES> I will ever have the courage to run this thing at full       
 ES> power.

This system is using the 6.25 dia. by ~26-28 inches tall
secondary I believe? The additional toriod no doubt increased
your base current as well. This is big spark production, time to
think about wetting that ground down before firing!

Have you done any ground current experiments?

 ES> I think I have a problem which must be common to high power, 
 ES> large toroid systems.  As I slowly increase power, the spark 
 ES> gaps finally start to fire, then before the discharger       
 ES> breaks out a very strong blue corona builds up from the top  
 ES> of the secondary down to the top of the primary - in the     
 ES> shape of a christmas tree.  

You are actually looking at the precise shape of the primary/
secondary field flux with the naked eye. 

The lines of force are clearly mapped by ionization of the air,
showing both the size of the field, but also relative energy
densities. Using large "saucer shaped" or inverted conical
section primaries, the field flux resembles a space capsule in
shape; the ionization begins on the primary conductor (the
rounded "heat shield" of a space capsule) and the field narrows
the further up the secondary you go. The field terminates on the
last turn of the secondary, just below the toriod. Brighter
areas, or areas marked by actual spark discharges, indicate
higher stress locations where breakdown is likely to occur, or is
already occurring.

 ES> I used to think this was pretty.  Now, with the larger       
 ES> discharger which requires more power to cause breakout, the  
 ES> corona gets so intense that streamers start forming
 ES> in the corona and I did see sparks discharging on the        
 ES> secondary itself from the top down to the bottom.  I am      
 ES> concerned this will ruin my secondary.  Is this correct?     
 ES> What can I do about it?  Should I increase the variac        
 ES> voltage quickly through this area to minimize the corona     
 ES> build-up and discharges? 

You are overdriving the six inch coil a bit in your efforts to
peak the system out. The splashes of spark back and forth between
the primary and secondary coils, and up and down the sides of the
secondary, is a visual sign of overcoupling. The inductive
interaction (coefficient of coupling) must be loosened to bring
the coil to it's peak. Raise the secondary coil up on insulators
an inch to three inches (possibly more), to loosen the coupling
between the coils. Overcoupling of the secondary coil causes the
coil frequency to "split". Since the coil cannot accept all of
the energy at one resonate frequency, parasitic resonance will
establish in the coil. Splitting is seen in the coil because the
parasitic resonances establish at higher frequencies. The 1/4
wave voltage peaks of the higher frequency parasites appear in
the windings of the coil, as seen by the sparks jumping up and
down between turns, and to the ground terminal. They are damaging
as the spark trails can eventually carbonize and cause insulation
failures.

The coil does not process energy at peak efficiency when it is
overcoupled. The best coil output is achieved when the system is
adjusted to the point where maximum resonance is achieved in the
secondary. Resonance in a coil that is overcoupled is inhibited
by the powerful field flux, which damps the coil VSWR.   

Large toriods really allow better resonance, they aid in
relieving overloaded coils, and assist greatly in coil
efficiency. But toriod height problems can inhibit resonance, so
experiment with the height of the toriod. 

A larger diameter secondary coil (say that eight inch coil) will
be more efficient and will withstand greater loading. Coil Q
increases somewhat as charge densities decrease, and larger
diameter coils have lower charge densities. This also offers the
opportunity to perhaps bump up the wire size a notch. Just a
thought.

I will drop in a note here about Tesla Magnifiers: coupling can
be much greater between the primary and secondary coils on Tesla
Magnifiers. Inhibited VSWR in the secondary coil from tight
coupling does not impair the efficiency of the Magnifier system.
The secondary coil in the Magnifier is producing current to
supply the extra coil, not voltage. Voltage gain in the secondary
coil of a Magnifier system is primarily due to ratio of turns
transformation, not resonance. The extra coil resonates free and
unrestricted from any field flux, energy being supplied in the
form of RF current which is fed into the base of the coil.

Your work has been progressing admirably.

Richard Quick


... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12