Cecil Moore wrote:
On Oct 18, 6:43 pm, Jim Lux wrote:
... assuming simultaneity isn't a big stretch.
... yes, the speed of light matters, ...

These two concepts seem to be contradictory. Some simple 1/4WL Tesla
coils are obviously close to 90 degrees long and limited by the speed
of light. The traveling waves cannot travel faster than the axial
propagation factor, whatever that value might be. For those simple
Tesla coils, there is an electrical ~1/4WL between the feedpoint and
the spark. Simultaneity is impossible in the real world.

(Thanks for the email invite, but right now most of my time is
dedicated to learning how to be a square dance caller.)
--
73, Cecil, w5dxp.com

The actual physics isn't of interest. What's of interest is "does the
model replicate the observed behavior of the real system" and "do
changes to the model produce changes comparable to that of the real
system in a fashion that is good enough to allow systems to be designed
and work on the first try".

The lumped model is sufficient for both of these.

The "traveling wave" model is also sufficient, but is substantially more
complex, and doesn't bring advantages to the design process.

Tesla coils can be modeled very well by a lumped model with a half dozen
components and nodes.