Re: Tesla Group Archives

Quoting Jim Oliver:

 JO> I think the main headings are right on the button, really    
 JO> good. Do you think a specific heading for "Important         
 JO> formulas" (to calculate the main parameters) should be       
 JO> included ? 


 JO> Could this be handled by simply giving the lit. refs ?

Not as effectively as including a math section. I have an ASCII
math file that I can upload as a post to the group. Additions can
be made by various members and the expanded file can be included
as part of the FAQ.
 JO> It's been said before that coiling as we do it is a "sort of
 JO> art", but it's important in any serious study to separate    
 JO> the art from the science. The construction of Tesla coils    
 JO> should not be seen totally as an "art" in itself, this is    
 JO> obviously untrue as evidenced by the huge number of          
 JO> scientific studies of the "Tesla transformer" and associated 
 JO> hardware. There is ample proof that the operation is easily  
 JO> and accurately predicted by theory given accurate components 
 JO> and construction. 

 JO> If it is regarded as an art, then this shows some reluctance 
 JO> on the part of the constructor to accept the part played by  
 JO> the science and theory of the coil. By understanding this    
 JO> well we can begin to build with real confidence. Of course   
 JO> constructors of long experience probably apply more science  
 JO> than they are aware of, or are able to explain to less       
 JO> experienced people.

I don't think that any person would dispute that Tesla was, and
remains, the supreme master of resonate coil systems. Yet Tesla
left no math legacy. Tesla was not a mathematician. In fact
Tesla's math was not a whole lot better than mine, and I am a
very poor mathematician. Tesla never derived or used any math
more difficult than algebraic equations and functions, and
Tesla's math never explained what was going on or how to
reproduce it. 

In the CSN (Colorado Springs Notes) Tesla laid out a lot of coil
math. In the commentary by Aleksandar Marincic, Assoc. Prof. of
EE Beograd Univ., many of Tesla's mathematical errors are pointed
out. Other's came along much later and began to decipher the
mathematics of Tesla coil components, but nobody has produced a
set of definitive equations that accurately predict the
performance of Tesla systems. 

Dr. James and Kenneth Corum are probably the two of the best
Tesla mathematicians on the planet today. In their book, "VACUUM
TUBE TESLA COILS" they published third order calculus equations
to explain many functions of Tesla's Colorado Springs Machine.
But they already knew the answers. Tesla gave the experimental
results in the CSN in text form, not in third order calculus
equations. In 1993 The Corums collaborated with William Wysock
(an experienced Hollywood coiler) of Tesla Technologies out of
Monrovia California. In July 1994 William Wysock assembled a
large Tesla Magnifier in Colorado Springs as part of the ITS
Tesla Symposium. This coil system was mathematically calculated
and designed by the Corum's and was assembled on location at the
rodeo arena by William Wysock at the cost of many, many,
thousands of dollars. It was to be a crowning achievement for
both the Corum's and Wysock.

The coil was a disastrous failure. It refused to tune. It refused
to quench. When fired, the entire system with extra coil operated
as the much simpler 1/4 wave resonator; there was no 1/8 wave
node on the transmission line; in fact the transmission line
acted as an uncoupled turn in a larger 1/4 wave system. Repeated
efforts to make adjustments, bring the coil into tune, etc.,
resulted in the self-destruction of the large rotary gap
specially built for the project. The coil was never even
demonstrated before the public. A hail storm passing over the
rodeo grounds was blamed for the destruction of the equipment (an
outright lie) and the public demonstrations of the project were

So much for using coil math to directly design coil systems. IMHO

I could also point out that there is at this moment a HUGE debate
going on as to the theoretical treatment of Tesla coil systems.
One side of the debate states emphatically that Tesla coils are
best described mathematically by transmission line theory. The
other side states that Tesla coils are best described as lumped
tuned circuits.

Both sides have valid points. Neither view completely explains
what is going on. Even basic Tesla coil systems have yet to be
accurately mathematically described. You simply cannot build an
entire series of good Tesla coils using math as your primary
tool. You might mathematically describe one design, but scaling
the size, or power levels, up and down will throw everything off.
Despite what anyone says, coil designs that are derived primarily
from mathematical calculations will not function well.

 JO> "Tweaking" in the end will produce results, but this         
 JO> tweaking is always the result of experience _and_ science.   
 JO> One can get there much quicker by accepting and using a      
 JO> certain number of basic formulae.

Nobody can tweak or tune a coil faster mathematically than I can
with a glance. This may sound conceited, but I challenge anybody
to come even close. In my mind, Tesla coils are an art form. Once
they are up and tuned perfectly, then I can get out the
calculator to explain what I did.

I used to run computer simulations of coil designs to better
understand the system parameters before construction. Waste of
time. I found the best way to design was to experiment. I would
set up my workstation and fabricate primary coils from lengths of
old wire. By changing the coil type, spacing, angle of
inclination, etc., I was able to determine EXACTLY the type,
size, shape, number of turns, etc., worked best with any given
secondary design. I was able to do this at various power levels,
with various secondary types (space wound, close wound, insulated
wire wound). I charted my data, then compared my charts to the
computer simulations. Finally I abandoned the computer and relied
on the charts. I guess it was not long before I memorized and
interpolated the chart data, next thing I knew I was designing
freehand with no references or aids at all...

 JO> (Out of interest some of these <mathematically designed      
 JO> coils?> use up to 100kV into 20 microfarad for the primary   
 JO> circuits. One uses a pressure vessel filled with
 JO> sulphur hexafluoride to 60 psi as an insulator ! Peak        
 JO> voltages are up to 2.5 MV. Capacitors are often of the water 
 JO> type)
 JO> In all cases the theory closely predicts the performance.

Yet Tesla was exceeding these voltages, (and RMS amps too I would
guess) in 1899 with wooden coil forms and gutta-percha insulated
wire, using no more than .12 microfarads tank capacitance shock
excited at 60kV. To my knowledge Tesla's 9.5 MV peak -at- 1100 RMS
amps in the helix still stands as a record 96 years later. 

In Tesla's case the art form still transcends theoretical science
despite nearly 100 years of advancement in the later.
 JO> The art as I see it is a learned appreciation of the         
 JO> materials and some parts of the construction and is separate 
 JO> from the actual determination of the various quantities      
 JO> involved (capacitance, inductance etc) and their             
 JO> relationships.

I would maintain that the proficient coiler can reach a point
where most common Tesla coil configurations would require no
calculations whatsoever. I would agree that you do not get to
this level of proficiency without doing a fair share of
calculations, yet still I would maintain that it is possible to
achieve this level of proficiency by pure experimentation and

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