Re: Flat Spiral Tesla Coils
From: Bert Wikkerink[SMTP:bert-at-mitra-dot-com]
Sent: Tuesday, July 01, 1997 8:56 AM
To: Tesla List
Subject: Re: Flat Spiral Tesla Coils
Tesla List wrote:
> From: Richard Wayne Wall[SMTP:rwall-at-ix-dot-netcom-dot-com]
> Sent: Monday, June 30, 1997 5:46 PM
> To: Tesla List
> Subject: Flat Spiral Tesla Coils
> Nikola Tesla in the June issue of the 1919 Electrical Experimenter
> wrote the fifth article in a series called "My Inventions". In this
> article he states that his laboratory was destroyed by fire in 1995.
> NT wrote, " . . . . This calamity set me back in many ways and
> most of that year had to be devoted to planning and reconstruction.
> However, as soon as circumstances permitted, I returned to the task.
> Although I knew that higher electro-motive forces were attainable with
> apparatus of larger dimensions, I had an instinctive perception that
> the object could be accomplished by the proper design of a
> comparatively small and compact transformer. In carrying on the tests
> with a secondary in the form of a flat spiral, as illustrated in my
> patents, the absence of streamers surprised me and it was not long
> before I discovered that this was due to the position of the turns and
> their mutual action. Profiting from this observation I resorted to the
> use of a high tension conductor with turns of considerable diameter
> sufficiently separate to keep down the distributed capacity, while at
> the same time preventing undue accumulation of the charge at any point
> The application of this principle enabled me to produce pressures of
> 4,000,000 volts which was about the limit obtainable in my new lab
> oratory at Houston Street as the discharges extended through a distance
> of 16 feet. A photograph of this transmitter was published in the
> Electrical Review of November, 1998. . . . "
> Tesla goes on to say that he had to go out in the open and this
> ultimately was why he went to Colorado Spring in 1999 where he remained
> for more than one year.
> Recently, others on this list have had NT's same experience of very
> unimpressive flat spiral discharges. Tesla nailed the problem of high
> interturn distributed capacitance and seems to have corrected it with
> spaced windings and high tension conductors. I'm not sure he could
> accurately measure a 4,000,000 volt discharge, but he could probably
> quite accurately measure a 16 foot discharge. To wit, our TC
> measurement technologies have not changed that much in a century.
> None the less, Tesla was quite successful in design and function of his
> flat spiral geometries which were far more compact than his helical
> coils. To that end, perhaps we should investigate the various
> parameters of flat spiral secondaries such as distributed capacities
> and inductances as we do in the helical varieties. After
> "conventional" flat spiral secondaries are re-researched, a logical
> extension would advance to "magnifier" spiral secondaries. And,
> ultimately flat spirals in liquid N2.
I guess that we will have to wait a few years before they publish these
articles. I always thought that time travel would be cool, and it
appears that tesla accomplished it. ;-)