Re: Secondary Resonance LC and Harmonics.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Chris,

At 01:53 PM 6/26/2005, you wrote:
> Hi All,
>
> Does the formula  f0 = c/4 x 1 (c=light m/s, l=wire length.) and this 
> statement by Tesla mean anything to anyone?
>
> "The exact attunement of the two circuits (windings) secures great 
> advantages, and, in fact, it is essential in the practical use of the 
> system In order to attain the best results it is essential that the length 
> of wire, from the ground connection to the top, should be equal to 
> one-quarter of the wavelength of the electrical vibration of the 
> wire."  -Dr Tesla

Yes!  It is "extremely" well known!!  BUT, it's wrong!!!!!

The Corums will argue ;-))

http://www.ttr.com/corum/index.htm

I will too :O))))

http://www.pupman.com/listarchives/1999/October/msg00428.html

It could be argued we both talk about the same thing in a different 
way...  Paul's stuff is really where is at:

http://www.abelian.demon.co.uk/tssp/


> Are we assuming the electrons in the wire are reaching a relatavistic 
> velocity due to the high potential?

No...  It is just plain old every day radio engineering stuff....  In a 
straight wire, electricity propagation does near the speed of light.  In a 
coil, it is vastly less!!!
For a straight wire, the formula Tesla used, based on the speed of light, 
works very well given a velocity factor....


> http://www.griffithobs.org/exhibits/Tesla%20Coil%20Exhibit/tcoil.html

They "correctly" give the formula:

fo = 1/(2 x Pi x sq. root LC)

"L" is easy to find...

http://web.archive.org/web/20040308060705/http://home.earthlink.net/~electronxlc/formulas.html

"C" is a SOB to find with a top terminal (Medhurst other wise, see 
above)...  But computers can "now" do it to a fraction of a percent accuracy...

http://hot-streamer.com/TeslaCoils/Programs/E-Tesla6.zip

http://www.classictesla.com/java/javatc.html

The giant problem with Tesla's velocity of light equation is that is a 
"coil", not a "straight wire".....  The top of the coil is magnetically 
linked to the base!  A current in the base only has to go like three feet 
before it affects the top of the coil...  Today, the velocity of light wire 
length calculations have long been replaced...

Although Tesla used that, he had great trouble with it...  I am sure he 
would be more than happy to forget all about it nowadays ;-)  But that is 
what he had at the time, for better or worse...

If you really want to dive into it:

http://hot-streamer.com/temp/pn2511.pdf

http://hot-streamer.com/temp/pn1401.pdf


> The coil in the diagram appears cone shaped, is this just the illustration 
> or would there be a practical reason for this?

The thought was that a small top would have a smaller top capacitance and 
reach a higher voltage.  Today, we load the top with a great big toroid for 
arcs that are 5X longer....  You need a big top toroid to give the arcs 
"power".  High voltage and little current does not work well...  Most coils 
that have big streamers do not have giant top voltages but they do have 
lots of power!!!

Over the years, we have answered these questions many times ;-))  But feel 
free to ask them again so we can get you all up to speed too!!  I hope we 
don't spend so much time running vast trillion calculation matrix equations 
on Tesla's CS coil model that we forget that there are folks out there 
making their first coils that need basic help too!!!  I note the list has 
gotten a little heavy on some off-topic stuff and "brainiac" stuff 
lately...  We need to bring things a little more in line with the rest of 
the coilers too ;-))))

BTW - I see Bill's site has some new stuff and even another paper by the 
Corums I have not seen!!

http://www.ttr.com/what's_new.htm

"i" will have to tie myself down before reading the Corum's paper :o))

Cheers,

        Terry



> Thanks
>
> Chris