Re: Tesla's Radio Circuit (was tuning more accurately than 5%) (fwd)
---------- Forwarded message ----------
Date: Fri, 24 Jul 1998 20:38:27 -0700 (PDT)
From: Michael Nolley <mhnolley-at-willamette.edu>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Tesla's Radio Circuit (was tuning more accurately than 5%) (fwd)
On Thu, 23 Jul 1998, Tesla List wrote:
> ---------- Forwarded message ----------
> Date: Thu, 23 Jul 1998 05:13:18 +0000
> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Tesla's Radio Circuit (was tuning more accurately than 5%)
> Richard, All -
> I disagree about Tesla having "honed what was first just a glorified
> induction coil system". The induction coil and the Tesla coil are two
> completely different electrical concepts.
> The induction coil stores electricity in a coil and produces a high
> voltage (inductive kick) when the circuit is OPENED. The Tesla coil stores
> electricity in a capacitor and produces a high voltage (in the secondary)
> when the circuit is CLOSED. There is much more.
> However, this is not the important radio aspect of the Tesla coil that
> Marconi stole from Tesla. Up until the time of Tesla's "Tesla coil"
> invention it was impossible to transmit more than microwatts using Hertz's
> circuits and radio waves. Tesla's invention was a dual RCL circuit that made
> it possible to go from microwatts to megawatts in radio transmitters. This
> is the concept that Marconi stole from Tesla. The US patent department was
> conned by Marconi into believing Marconi's circuit was a different concept.
> Even today the radio concept of Tesla's invention is not well known or
> John Couture
His comment, though, rings true, John-- Although I haven't much
in the way of data about Tesla's early coils-- I DO have his London
lecture from 1899 (see earlier post) "Experiments at high potentials and
high frequencies" Indeed, the coil here isn't designed for resonance--
it has an iron core, over 100 primary turns, the connection with the TC
is that it is charged by a "disruptively discharged capacitor". Already
Tesla had designed muliple gaps, air quenched, magnetic, etc. to improve
the performance of the coil-- but the standard form hadn't yet emerged.
The Tesla coil doesn't seem to have been "envisioned" but discovered
gradually. I don't contest the radio stuff-- but I think the induction
coil and the Tesla coil are closely related in geneology.