Chris Gupta
Attached is a GIF of the diagrams for this patent. It was in one of my
Tesla books. I don't have the patent descriptions, but someone else posted
the text part over on freenrg-l yesterday.
Here's a copy of what they posted - Enjoy.
UNITED STATES PATENT OFFICE.
NIKOLA TESLA, OF NEW YORK, N.Y.
COIL FOR ELECTRO-MAGNETS.
SPECIFICATION forming part of Letters Patent No. 512,340,
dated January 9, 1894.
Application filed July 7, 1893. Serial No. 479,804. (No model.)
To all whom it may concern:
Be it known that I, NIKOLA TESLA, A citizen of the United States, residing
at New York, in the county and State of New York, have invented certain new
end useful Improvements in Coils for Electro-Magnets and other Apparatus,
of which the following is a specification, reference being had to the
drawings accompanying and forming a part of the same.
In electric apparatus or systems in which alternating currents are employed
the self-induction of the coils or conductors may, and in fact, in many
cases does operate disadvantagely by giving rise to false currents which
often reduce what is known as the commercial efficiency of the apparatus
composing the system or operate detrimentally in other respects. The
effects of self-induction, above referred to, are known to be neutralized
by proportioning to a proper degree the capacity of the circuit with
relation to the self-induction and frequency of the currents. This has
been accomplished heretofore by the use of condensers constructed and
applied as separate instruments.
My present invention has for its object to avoid the employment of
condensers which are expensive, cumbersome and difficult to maintain in
perfect condition, and to so construct the coils themselves as to
accomplish the same ultimate object.
I would here state that by the term coils I desire to include generally
helices, solenoids, or, in fact, any conductor the different parts of which
by the requirements of its application or use are brought into such
relations with each other as to materially increase the self-induction.
I have found that in every coil there exists a certain relation between its
self-induction and capacity that permits a current of given frequency and
potential to pass through it with no other opposition than that of ohmic
resistance, or, in other words, as though it possessed no self-induction.
This is due to the mutual relations existing between the special character
of the current and the self-induction and capacity of the coil, the latter
quantity being just capable of neutralizing the self-induction for that
frequency. It is well-known that the higher the frequency or potential
difference of the current the smaller the capacity required to counteract
the self-induction; hence, in any coil, however small the capacity, it may
be sufficient for the purpose stated if the proper conditions in other
respects be secured. In the ordinary coils the difference of potential
between adjacent turns or spires is very small, so that while they are in a
sense condensers, they possess but very small capacity and the relations
between the two quantities, self-induction and capacity, are not such as
under any ordinary conditions satisfy the requirements herein contemplated,
because the capacity relatively to the self-induction is very small.
In order to attain my object and to properly increase the capacity of any
given coil, I wind it in such way as to secure a greater difference of
potential between its adjacent turns or convolutions, and since the energy
stored in the coil considering - the latter as a condenser, is
proportionate to the square of the potential difference between its
adjacent convolutions, it is evident that I may in this way secure by a
proper disposition of these convolutions a greatly increased capacity for a
given increase in potential difference between the turns.
I have illustrated diagrammatically in the accompanying drawings the
general nature of the plan which I adopt for carrying out this invention.
Figure 1 is a diagram of a coil wound in the ordinary manner.
Figure 2 is a diagram of a winding designed to secure the objects of my
invention.
Let A, Figure 1, designate any given coil the spires or convolutions of
which are wound upon and insulated from each other. Let it be assumed that
the terminals of this coil show a potential difference of one hundred
volts, and that there are one thousand convolutions; then considering any
two contiguous points on adjacent convolutions let it be assumed that there
will exist between them a potential difference of one-tenth of a volt. If
now, as shown in Figure 2, a conductor B be wound parallel with the
conductor A and insulated from it, and the end of A be connected with the
starting point of B, the aggregate length of the two conductors being such
that the assumed number of convolutions or turns is the same, viz., one
thousand, then the potential difference between any two points in A and B
will be fifty volts, and as the capacity effect is proportionate to the
square of this difference, the energy stored in the coil as a whole will
now be two hundred and fifty thousand as great. Following out this
principle, I may wind any given coil either in whole or in part, not only
in the specific manner herein illustrated, but in a great variety of ways,
well-known in the art, so as to secure between adjacent convolutions such
potential difference as will give the proper capacity to neutralize the
self-induction for any given current that may be employed. Capacity
secured in this particular way possesses an additional advantage in that it
is evenly distributed, a consideration of the greatest importance in many
cases, and the results, both as to efficiency and economy, are the more
readily and easily obtained as the size of the coils, the potential
difference, or frequency of the currents are increased.
Coils composed of independent strands or conductors wound side by side and
connected in series are not in themselves new, and I do not regard a more
detailed description of the same as necessary. But heretofore, so far as I
am aware, the objects in view have been essentially different from mine,
and the results which I obtain even if an incident to such forms of winding
have not been appreciated or taken advantage of.
In carrying out my invention it is to be observed that certain facts are
well understood by those skilled in the art, viz: the relations of
capacity, self-induction, and the frequency and potential difference of the
current. What capacity, therefore, in any given case it is desirable to
obtain and what special winding will secure it, are readily determinable
from the other factors which are known.
What I claim as my invention is:
1. A coil for electric apparatus the adjacent convolutions of which form
parts of the circuit between which there exists a potential difference
sufficient to secure in the coil a capacity capable of neutralizing its
self-induction, as herein before described.
2. A coil composed of contiguous or adjacent insulated conductors
electrically connected in series and having a potential difference of such
value as to give to the coil as a whole, a capacity sufficient to
neutralize its self-induction, as set forth.
NIKOLA TESLA.
Witnesses:
Robt. F. Gaylord,
Parker W. Page.
---mbgupta@julian.uwo.ca wrote:
>
> Many thanks, Anton
>
> Chris
>
> At 08:20 PM 7/4/98 -0700, you wrote:
> >
> >Hello,
> >
> >Read your post in KeelyNet-L. I'm not a subscriber, but read the
> >online archive often. I think I've seen that patent in a couple of
> >Telsa books. One might be "Inventions, Writings, and Experiments of
> >N.T." book. It covers most of his stuff up to 1890 or so, and has lots
> >of cool notes/writings by him covering coils and high freq stuff. The
> >other would be the book with all of N.T.'s patents. Both are
> >probably available at your local library. If you can't find it let me
> >know, I will find the book and scan the patent for you.
> >
> >
> >Anton Rager
> >a_rager@yahoo.com
> >
> >PS - feel free to forward this to KeelyNet-L
> >_________________________________________________________
> >DO YOU YAHOO!?
> >Get your free @yahoo.com address at http://mail.yahoo.com
> >
>
==
Anton Rager
a_rager@yahoo.com
_________________________________________________________
DO YOU YAHOO!?
Get your free @yahoo.com address at http://mail.yahoo.com
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