Re: big coil history

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

Hi Jim, all,
              The resonator behaves much like a 1/4 wave transformer
with one end grounded, free-end Z defined by that and Zo and so-on.
But the wirelength thing was something Tesla desperately tried to
reconcile in his writings. Nature forced him to give up trying and he
resorted to the lumped parameters to get some answers as to why his
resonators were resonating as they did. I guess it's time to get the
Notes out again and refresh the grey matter over the weekend.
        Some of his writings were pretty handwaving stuff - he once
said that the primary should be half a wavelength long at Fr for at
least one of his machines but then conceded that in fact it had to
resonate in sympathy with the secondary in order to work properly.
I'm now trying to recall whether he actually calculated the voltage
output of his machines using the classic energy conservation argument
using lumped parameters. I have a sneaking suspicion that he didn't
and that had he done so, would have been in for a bit of a shock
(npi). He did handwave a bit about unlimited output potentials and so-
on, probably in the context of CW driving the coil while all the time
running his highest powers using disruptive discharge. Yep - time to
re-read the CS Notes.

Malcolm

On 31 Mar 2005, at 20:27, Tesla list wrote:

> Original poster: "Jim Lux" <jimlux@xxxxxxxxxxxxx>
>
> Maybe it's the quarter wave transmission line transformer thing?
> Could it be Ferranti for spelling? (there's a well known Italian HV
> company of that name)
>
> ----- Original Message -----
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Thursday, March 31, 2005 6:19 PM
> Subject: Re: big coil history
>
>
>  > Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>
>  >
>  >
>  >
>  > The 1/4 lamda myth was strongly advocated and propagated by a
>  number of > Physics textbooks many of which referred to it as "the
>  Ferrenti
> Effect" ---
>  > must be something Italian.
>  >
>  > Dr. Resonance
>  >
>  >
>  >
>  >  > Take a nice lumped theory Tesla coil model like this:
>  >  >
>  >  >
>  http://www.hot-streamer.com/TeslaCoils/MyPapers/modact/Image160.gif >
>   > >  > And try and work through it with pencil and paper ;-)) >  > >
>   > Today with computers and MicroSim like programs, "anyone" can do
>  it!!
> But
>  >  > if one tries to do it the hard way (and many many have tried!!),
>  you
> just
>  >  > can't do it....  Much like transmission line theory in 80's, the
>  tools > were >  > not there to workout the details....  Today,
>  Antonio has many papers
> where
>  >  > those details "have" been worked to a very high degree!
>  >  >
>  >  > Also, today we can measure things with high confidence. In the
>  30's and >  > 40's, they just did not have the test tools to "know"
>  what was going >  > on.  It is always far easier to know what the
>  system is doing with real >  > measurements and "then" fit the theory
>  ;-)) >  > >  > In the old days I am sure many worked things and found
>  the terminal > voltage >  > of a coil with say 10 foot streamers to
>  be 300kV...  Well, that was >  > obviously "wrong" !! :o))  10 feet
>  at 10kV/inch is 1,200,000 >  > volts...  Tesla always gave coils
>  super high voltages too...  If the >  > physics did not agree with
>  Tesla then the physics was obviously wrong >  > because Tesla
>  certainly was not...  I think a lot of the mess got
> started
>  >  > just that way...
>  >  >
>  >  > Of course, we all know who started the 1/4 wavelength of wire
>  idea
> ;-)))
>  >  >
>  >  > http://www.pbs.org/tesla/tt/images/tt_main.jpg
>  >  >
>  >  > "Probably through misinterpretation of something Tesla said?"
> Actually,
>  >  > direct and accurate interpretations of what Tesla said...
>  >  >
>  >  > If he would have had a good scope, think of how different it
>  would all
> be
>  >  > now!!!!  If anyone gets that time machine working, we gotta send
>  Tesla
> a
>  >  > scope!!!  If Tesla had a scope, maybe we would have time
>  machines now!! > ;o)) >  > >  > Cheers, >  > >  >          Terry >  >
>  >  > >  > At 01:02 PM 3/31/2005, you wrote: >  > >"Given that folks
>  in the 30s and 40s were using the lumped LC analysis >  > >approach
>  (and it had certainly been around before that), it would be >  >
>  >interesting to see where, when, and why, the 1/4 wavelength of wire
> idea
>  >  > >started to be used."
>  >  > >
>  >  > >         Probably through misinterpretation of something Tesla
>  said? >  > > >  > >Ed >  > >  > >  > > >
>
>
>