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Re: Classic coil
Tesla List wrote:
>
> >> Subject: Classic coil
> >Subject: Re: Classic coil
> >> Subject: Classic coil
>
> >From couturejh-at-worldnet.att-dot-net Sat Dec 7 08:43:46 1996
> Date: Sat, 7 Dec 1996 06:43:04 +0000
> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: Classic coil
>
> At 06:00 AM 12/6/96 +0000, you wrote:
> >> Subject: Classic coil
> >
> >>From hullr-at-whitlock-dot-com Thu Dec 5 22:26:25 1996
> >Date: Sun, 26 Mar 2000 21:29:01 -0800
> >From: Richard Hull <hullr-at-whitlock-dot-com>
> >To: tesla-at-pupman-dot-com
> >Subject: Re: Classic coil
> >
> >Tesla List wrote:
> >>
> >> >From Hans.Grimstad-at-maxware.no Sun Dec 1 22:28:46 1996
> >> Date: Sun, 1 Dec 1996 23:34:05 +0100
> >> From: Hans.Grimstad-at-maxware.no
> >> To: tesla-at-pupman-dot-com
> >> Subject: Classic coil
> >>
> >> Hello everyone !
> >>
> >> I have been rereading my reprint of Teslas lecture to the Institution of
> Electrical
> >> Engineers in London. On page 15, he describes a small bipolar coil. Each
> of the
> >> terminals of the coil is connected to a circle, one is 80 cm in diameter,
> the other is
> >> 30 cm in diameter. During operation of the coil, the discharges between the
> >> terminals produce a "luminous sheet" with an area of about 0.43 square
> metre. He
> >> states that he in earlier experiments, using bigger circles had covered
> an area of
> >> more than one square metre.
> >> This coil has 2 primaries with 96 turns in each, and two secondaries with
> 260 turns in
> >> each. When both the primaries and the secondaries are connected in
> series, this
> >> gives a ratio of conversion of about 1:2.7.
> >>
> >> It seems that a lot of people are designing coils with much bigger
> conversion ratios
> >> (1:67 for a coil with 1000 windings on the secondary and 15 on the
> primary). I would
> >> say that Teslas results with this coil are quite impressive. Why the big
> secondaries
> >> in "modern" coils ?
> >>
> >> Hans J|rgen Grimstad
> >
> >
> >Hans,
> >
> >I am late getting to this message and have not read all replies, but here
> >goes.
> >
> >In a resonance system the tranfomation ratio doesn't hold as you have
> >computed. We get much more out of the system than those simple ratios
> >might imply.
> >
> >Next, modern coils are going for spark. Spark is a function of secondary
> >inductance. Tesla's demo system was not a hot performer. Tesla also
> >used very tight coupling in his early systems of the early 1890s and this
> >would hurt their performance. He learned this as he progressed towards
> >his 1899 super system.
> >
> >Richard Hull, TCBOR
> >
> ---------------------------------------------------
>
> Richard -
>
> Was'nt that an induction coil with an iron core and the action was by
> "inductive kick" pulse wave instead of by dampened sine waves like a true
> Tesla coil? The induction coil operates on a completely different type of
> electrical mode, di/dt. This type of coil cannot be built to produce high
> voltages and power like the Tesla coil.
>
> Jack Couture
Jack,
You are only partially correct. The coil did, indeed, have an iron core
which made the coupling fearsome. However he used spark excitation and
the system was really just a lousey Tesla coil. It worked via damped,
albeit ragged assed, damped oscilltions. It combined all the worst
features of the induction coil with some of the better features of the
pure Tesla coil. He had to learn too you know. This was his first blush
pass at HV resonant systems.
I wouldn't recommend this kind of coil to anyone! The entire book edited
by T.C. Martin was cutoff in early 1893 and thus contains only
historically interesting information on Tesla's earliest work only! It
should not be studied with a "how to do it" mentality.
Richard Hull, TCBOR