Re: [TCML] VTTC New Grid Coil Geometry

[futuret@xxxxxxx]

Hi Dr. John,

I look forward to the time when you are able to finish the research  
work on the coil
and report more findings.  It all sounds intriquiing to me.

John
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-----Original Message-----
From: Dr. John W. Gudenas <comsciprof@xxxxxxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Wed, 17 Sep 2008 7:21 pm
Subject: Re: [TCML] VTTC New Grid Coil Geometry


Greetings John 
The pancake grid coil, on initial experiments, seems to be a very 
stable arrangement. 
I did find that I could reduce the number of turns on the pancake so 
that the variac could be cranked up higher before the voltage was 
sufficient to oscillate. 
This is a minor advantage as you can run up the plate voltage without 
hitting the grid with too much voltage. As with all VTTC tuning was 
critical. Simply 
using the reduced size toroid improved performance greatly. I won't 
know exactly how improved, until I get the thing on a lower bench, but 
when you have been around these VTTCs it isn't hard to see improvement. 
However, the sound and spark quality was consistent with the standard 
arrangement. I don't need a staccato controller yet and digital 
pictures verify the sword like sparks. What is amazing are the bright 
white power arcs and I am not sure yet how long they get. This coil has 
no metal except for wires & toroid and is five feet away from the power 
supply and=2
0oscillator, however, the tank capacitor is adjacent to the 
coil with short leads. 
 
It keeps the coil away from me ( reduce RF burns) and other surrounding 
elements that act as stray capacitance or antennas. My next run will 
use an HV twisted pair for the grid leak leads. 
There is much yet to learn, especially understanding the coupling 
Physics of the three coils. 
 
One thing, you are right on. It looks really neat and clean with the 
hidden grid coil and flash over is eliminated. 
 
Incidentally, thanks for spinning all the different size toroids. Due 
to your efforts I have accumulated a set that stacks like a toroid 
christmas tree. 
Regards 
John W. G. 
 
John W. Gudenas, Ph.D. 
Professor of Computer Science 
 
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