Re: Theory vs. Measurement, was: Re: Isotropic Capacitance
Richard Hull said:
>There is a vast difference between theoretical physics and application
>engineering. Most coilers ae seeking answers, and in doing so, they grab
>the physics texts and apply the equations only to discover they are off
>by 20% (in this case). They are actually trying to engineer a coil
>system, but expecting too much out of the math. As an engineer, myself,
>I have long used equations as a directional measure only and have come to
>expect "out of the ball park" answers.
I differ somewhat in my opinion of the utility of theory in tesla
coil construction. While fully I agree that the math may only get me to
within 10-20% for an operating tesla coil, I see it as another tool on the
shelf which should be used just like your oscilloscope, VOM, or B & K
inductance meter (I wish).
As an example, I wanted to better understand how different primary
coil geometries couple to secondaries of various sizes and positions. This
could easily be accomplished by constructing a number of coils and testing
it. However, this takes time and materials, neither of which I have a lot
of lately. By simulating this on the computer, I was able to test thousands
of combinations and could then better direct my choices for experiments.
Nonetheless, I fully agree that theory and experiment often differ
significantly when tesla coils are fired, due to the inability of theory to
consider proximity effects, A.C. resistance, corona clouds, humidity
effects, capacitive coupling, ground loops, parasitic oscillations and a
host of other things. A few experiments to confirm or deny the
applicability of the theory, often directed by the results of the theory,
make this approach equally valid in my opinion.
Mark S. Rzeszotarski, Ph.D.