[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [FwdX: [TCML] High Primary Q]



Hi Dave,

The issue is that it has been stated high Q and I was working with someone else off line regarding a flat ribbon primary (which is why I showed that particular calculation). In the process of looking, it didn't look high at all and so I thought I'd throw it at the list.

I'm going to send you a paper which I think you'll find interesting regarding spark gap resistance. It's by Harrison, Ferguson, and Monjo from Maxwell Laboratories: "Determining The Losses In Spark Gap Switches".

I'll send as a pdf.

Take care,
Bart

David N. Van Doren wrote:
Hi Bart
I don't see what the issue is.
Q has always been Reactance divided by Resistance.
The trick it to determine the real resistance.
Copper losses are just one source of losses.
One can calculate the skin depth of a tube and
use the resulting thin walled tube as the conductor.
But according to Dr Gary L. Johnson's Tesla Coil Paper,
Table 1, Proximity effects, skin depth R can be multiplied
by a factor of a little over 1 to as much as 5, depending
on the coil design.
But for me the biggest uncertainty of primary circuit losses
is in the spark gap. The conditions the determine the gap
Resistance can and do vary wildly. The gap resistance of
a coil running kiloAmps is most like very different
from a coil running a couple hundred amps.
This is what prompted me to ask the list what
it knew about Spark Gap Resistance.
Gap resistance is very tough for me to measure and
until I have some definitive data I can only assume that
It could range as high as the R's of the copper.
Than I would like to prove to my self the effects of
Dielectric losses in the capacitor. I don't know
how to equate loss factor to equivalent resistive losses.
Maybe someone here can show me?
Then there are radiative losses and I don't know
any thing about this.
So in the end Q may in fact maybe quite abit lower.
Maybe this is why Tesla turned to the Magnifier,
to in crease the coefficient of coupling to reduce
the number of loss cycles the energy had to endure.

Dave


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla