Re: Wire Length (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sat, 16 Dec 2006 17:56:52 -0700
From: Gary Peterson <g.peterson@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Wire Length (fwd)

>>  Let me see if I am getting this right.  For any given wire length
>> and number of turns-per-inch there is a unique solonoid
>> height-to-diameter ratio at which maximum inductance occurs,
>> and this H/D ratio is approximately 9/1.  Is that correct?

>      NO......it's the RADIUS....not the diameter
>  Mike

>     Actually, it is the H/R ratio that is  0.9/1.0  H = 0.9 R,
> or H = 0.45 D that gives the maximum inductance for
> a solenoid. . . .
>    The problem with a coil of this ratio is the very high
> voltage gradient (dV/dh) and the very short separation
> between the topload and the primary. . . .
> Matt D.

So, the maximum inductance of a single-layer solonoid winding occurs when 
its height-to-diameter ratio is close to 0.45/1.0.

> . . . but it's not a very practical value for
> TC work due to flashover problems. . . .
> Dr. Resonance

A high voltage gradiant and possible flashover are not always problems.  In 
1898 Tesla adopted a .43/1 H/D ratio in the design of a receiving coil that 
was used in conjunction with his 8-foot diameter flat spiral transmitter. 
[Nikola Tesla  Guided Weapons & Computer Technology, Leland I. Anderson, 
Twenty First Century Books, 1998, p. 12.]  Another receiving coil had an H/D 
ratio of about .31/1.  Four other Tesla coil receivers, resembling tables, 
are known to have existed. [ibid, pp. 16 & 41]  One of these had an H/D 
ratio of .45/1 [N. T. on His Work With Alternating Currents and Their 
Application to Wireless Telegraphy, Telephony and Transmission of Power : An 
Extended Interview, Leland I. Anderson, Twenty First Century Books, 1992. p. 
150], two .47/1 and another .55/1.  To this day, .33/1 resonators are being 
used in conjunction with wireless energy transmission and reception 
experiments. ["The Wireless Transmission of Electrical Energy," William 
Wysock, Telluride Tech Festival, Aug. 10-12, 2005.]

Gary Peterson