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Re: Isotropic Capacity
Subject: Re: Isotropic Capacity
Date: Thu, 22 May 1997 06:59:45 +0000
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
At 02:23 PM 5/20/97 +0000, you wrote:
>Subject: Re: Isotropic Capacity
> Date: Tue, 20 May 1997 00:26:51 -0400 (EDT)
> From: richard hull <rhull-at-richmond.infi-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
>
>
>At 09:46 AM 5/19/97 -0500, you wrote:
>>Subject: Isotropic Capacity
>> Date: Mon, 19 May 1997 06:25:24 +0000
>> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>> To: tesla-at-poodle.pupman-dot-com
>>
>>
>> To All -
>>
>> The dictionary defines "Isotropic" as "equal physical properties along
>>all
>>axes". As an example, an isolated charged sphere in space would have an
>>isotropic capacity because the charge on the sphere would extend equally
>>in
>>all directions.
>>
>> Isotropic capacity can only be a theoretical possibility. However, if
-------------------------------- Big snip
>We did a bunch of real world measurements with real terminals and found
>that
>a toroid in space hung over the ground really kept its isotropic
>capacity to
>within 3% when within 5 large dimension diameters of the ground. Thus a
>12X3" inch toroid is isotropic about 5 feet off the ground. We put most
>of
>the tests on a report tape. We also tested various wound resonators for
>frequency variations, with elevation too. This also related to altitude
>but
>related more to the diameter and l/d ratio of the coil. A 1"X10 coil
>was
>the same frequency at 18" off the grounded plane as 60" up. A 10"X36"
>resonator needed to be 3-4 feet off the floor before stabilizing.
>
>R. Hull, TCBOR
>
-----------------------------------------------------------
Richard and All -
Schoessow's TCBA article on isotropic capacity has unfortunately
mislead
many people. The reason is that he misinterpreted the Webster definition
for
"isotropic" that he quoted. Isotropic and capacitance are two words
with
very different meanings and do not make sense when used together. The
definitins are:
1. Capacitance - The property of an object to store a quantity of
electricity (coulombs). C = Q/V. Capacitance varies with the
size,
dielectric, etc.
2. Isotropic - The property of an object that extends equally in all
directions from an object. For example, a charged object produces
electric
lines of force extending equally in all directions.
The capacitance and isotropic properties are different properties and
require different measurements. R Hull measured the capacitance but not
the
isotropic properties of " real terminals'. The isotropic properties are
lines of electric force which are not capacitance and are difficult to
measure.
The sun is an example of producing isotropic light because the light
from
the sun extends equally in all directions. Note that it would be
incorrect
to say the sun has isotropic mass. The mass does not extend in all
directions as does the light.
A light bulb cannot have isotropic light because of the metal base that
prevents an equal distribution of light in all directions. Note that it
would be incorrect to say that the ligh bulb has isotropic watts because
watts does not extend beyond the bulb.
An isolated sphere in space that is not charged does not have isotropic
properties or electric lines of force. However, it does have the
property of
capacitance or the ability to store an electrical charge. It would be
incorrect to say that it has isotropic capacitance.
An isolated sphere in space that is charged has both isotropic and
capacitance properties. This could vagely be called an isotropic
capacitance. The electric lines of force due to the charges would extend
equally in all directions.
Tesla terminals that are charged are non-isotropic because the electric
lines of force are not equally extended around the terminal. However,
they
do have the property of capacitance and the ability to store electrical
charges. Schoessow's article gives the equations for finding the
capacitance
of various size terminals.. Saying that these terminals have isotropic
capacitance would be incorrect.
When a metal sphere or TC Terminal is brought near the ground or other
object the capacitance will change. If they are charged the electric
lines
of force around the sphere or terminal will not be equally divided and
this
condition is non-isotropic. However, it should be noted that the
non-isotropic property is not directly related to the capacitance. It is
obvious that the words "isotropic capacitance" do not make sense.
Measuring the capacitance of a TC terminal while it is moved toward or
away from ground in relatively easy. However, measuring the
non-isotropic
properties would be a tedious job as it would require drawings showing
many
lines of electrical forces around the terminal.
It is interesting to note that radio engineers use an isotropic antenna
as
a theoretical reference for the gain of real world antennas. This
reference
antenna is isotropic because it is considered as radiating
electromagnetic
fields equally in all directions. Capacitance is not involved.
John Couture