(No Model.)
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`No. 454,622.
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`-
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`N. TESLA
`SYSTEM OF ELECTRIC LIGHTING,
`Patented June 23, 1891.
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`T.
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`-27A227.7zaas.
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`Momentum Dynamics Corporation
`Exhibit 1009
`Page 001
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`UNITED STATES PATENT OFFICE.
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`NIROI, A TEs I, A, OF NEW YORK, N. Y.
`SYSTEM OF ELECTRIC LIG HTING
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`5
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`SPECIFICATION forming part of Letters Patent No. 454,022, dated June 23, 1891.
`Application filed April 25, 1891,
`Serial No. 390,414 (No model.)
`To all whom it may concern:
`Be it known that I, NIKOLATESLA, a sub
`ject of the Emperor of Austria-IIungary, from
`Smiljan, Lika, border country of Austria-Hun
`5 gay, and a resident of New York,in the county
`and State of New York, have invented certain
`new and useful Improvements in Methods of
`and Apparatus for Electric Lighting, of which
`the following is a specification, reference be
`Io ing had to the drawings accompanying and
`forming a part of the same:
`.
`.
`.
`This invention consists in a novel method
`of and apparatus for producing light by means
`of electricity.
`For a better understanding of the inven
`tion it may be stated, first, that heretofore I
`have produced and employed currents of very
`high frequency for operating translating de
`vices, such as electric lamps, and, second,
`20 that currents of high potential have also been
`produced and employed for obtaining lumi
`nous effects, and this, in a broad sense, may
`be regarded for purposes of this case as the
`prior state of the art; but I have discovered
`25 that results of the most useful character may
`be Secured under entirely practicable condi
`tions by means of electric currents in which
`both the above-described conditions of high
`frequency and great difference of potential
`3o are present. In other words, I have made the
`discovery that an electrical current of an ex
`cessively small period and very high poten
`tial may be utilized economically, and prac
`ticably to great advantage for the production
`35 of light.
`-
`It is difficult for me to define the exact lim
`its offrequency and potential within which my
`(liscovery is comprised, for the results ob
`tained are due to both conjointly; but I would
`4o make it clear that as to the inferior limits of
`both, the lowest frequency and potential that
`I contemplate using are far above what have
`heretofore been regarded as practicable. As
`an instance of what I regard as the lowest
`45 practicable limits I would state that I have
`obtained fairly good results by a frequency
`as low as fifteen thousand to twenty thousand
`... per second and a potential of about twenty
`thousand volts. Both frequency and poten
`5o tial may be erormously increased above these
`figures, the practical limits being determined
`by the character of the apparatus and its ca
`
`pability of standing the strain. I do not mean
`by the term “excessively small period’ and
`similar expressions herein to imply that I
`55
`contemplate any number of pulsations or vi
`brations per second approximating to the
`number of light-waves, and this will more
`fully appear from the description of the na
`ture of invention which is hereinafter con
`tained.
`The carrying out of this invention and the
`full realization of the conditions necessary to
`the attainment of the desired results involve,
`first, a novel method of and apparatus for
`producing the currents or electrical effects of
`the character described; second, a novel
`method of utilizing and applying the same
`for the production of light, and, third, a new
`form of translating device or light-giving ap
`pliance. These I shall now describe.
`To produce a current of very high frequency
`and very high potential, certain well-known
`devices may be employed. For instance, as
`the primary source of current or electrical
`75
`energy a continuous-current generator may
`be used, the circuit of which may be inter
`rupted with extreme rapidity by mechani
`cal devices, or a magneto-electric machine
`specially constructed to yield alternating cur
`rents of very small period may be used, and
`in either case, should the potential be too low,
`an induction-coil may be employed to raise it;
`or, finally, in order to overcome the mechani
`85
`cal difficulties, which in such cases become
`practically insuperable before the best results
`are reached, the principle of the disruptive
`discharge may be utilized, lyimeans of this
`latter plan I produce a much greater rate of
`change in the current than by the other means
`suggested, and in illustration of my invention
`Ishall confine the description of the means or
`apparatus for producing the current to this
`plan, although I would not be understood as
`limiting myself to its use. The current of
`95
`high frequency, therefore, that is necessary
`to the successful working of my invention I
`produce by the disruptive discharge of the
`accumulated energy of a condenser main
`tained by charging said condenser from a
`suitable source and discharging it into or
`through a circuit under proper relations of
`self-induction, capacity, resistance, and period
`in well-understood ways. Such a discharge is
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`Momentum Dynamics Corporation
`Exhibit 1009
`Page 002
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`C
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`35
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`454,622
`know in to be, under proper conditions, inter
`intermediate to the source of current, and the
`mittent or oscillating in character, and in this
`light-giving body. For this purpose the con
`way a current varying in strength at an enor
`ductors should be free from projections and
`Sinously rapid rate may be produced. Ilaying
`points and well covered or coated with a good
`produced in the above manner a current of ex
`insulator.
`cessive frequency, I obtain fron it by. Taeans
`The body to be rendered incandescent
`of an induction-coil enormously high poten
`should be selected with a view to its capa
`tials-that is to say, in the circuit through
`bility of withstanding the action to which it
`which or into which the disruptive discharge
`is exposed without being rapidly destroyed,
`75
`of the condensertakes place include the pri
`for some conductors will be much more speed
`nary of a suitable induction-coil, and by a sec
`ily consumed than others,
`ondary coil of much longer and finer wire co
`now refer to the accompanying drawings,
`vert to currents of extremely hig potential.
`in which
`The differences in the length of the primary
`Figure 1 is a diagram of one of the special
`and secondary coils in connection with the
`arrangements that I have employed in early
`enormously rapid rate of change in the pri
`ing out my discovery, and Figs, 2 and 3 are
`mary current yield a secondary of enormous
`vertical sectional views of modified forms of
`frequency and excessively high potenatial.
`light-giving devices that f have devised for
`Such currents are not, so far as Iain aware,
`use with the system.
`available for use in the usual ways; but have
`would state that as all of the apparatts
`discovered that if E connect to either of the
`herein shown, with the exception of certain
`terminais of the secondary coil or solarce of
`special forms of lamp invented by Ene, is or
`current of high potential the leading-in wires
`may be of well-known construction and in
`of such a device, for example, as an Ordi
`Common use for other purposes, I have indi
`nary incandescent lamp, the carbon may be
`90
`cated such well-known parts thereforby con
`brought to and maintained at incandescence,
`ventional representations,
`or, in general, that anybody capable of cone
`G is the primary source of curren & or elec
`ducting the high-tension carient described
`trical energy, I have explained above how
`and properly inclosed in a rarefied or ex
`various forms of generator night be used for
`hausted receiver may be rendered luminous
`30
`this purpose; but in the present, illustration.
`or incandescent, either when connected di
`assume that G is an alternating-current
`rectly with one terminal of the secondary
`generator of comparatively low electro-motive
`source of energy or placed in the vicinity of
`force. Under such circumstances raise the
`such terminals so as to be acted
`on induct
`potential of the current by means of an in
`ively.
`duction-coil having a primary P and a sec
`Without attempting a detailed explanation
`ondary S. Then by the current developed in
`of the causes to which this phenote on may
`this secondary charge a condenser C, and
`be ascribed, I deem it sufficient to state that,
`this condenser I discharge through or into a
`assuming the now generally accepted theories
`circuit A, having an air-gap (, or, in general,
`of scientists to be correct, the effects thus
`40
`means for maintaining a disruptive discharge.
`produced are attributable to molecular bom
`By the means above described a carrent of
`bardment, condenser action, and electric or
`enormous frequency is produced. My object
`etheric disturbances. Whatever part each
`is next to convert this into a working-circuit,
`or any of these causes may playin producing
`of very high potential, for which purpose A
`the effects noted, it is, however, a fact that a
`connect up in the circuit. A the primary P’ of
`strip of carbon or a mass of any other shape,
`an induction-coil having a long fine wire sec
`either of carbon or any more or less conduct
`ondary S. The current in the primary P.
`ing substance in a rarefied or exhausted re
`developsin the secondary S'a current or elec
`ceiver and connected directly or inductively
`trical effect of corresponding frequency, but
`to a source of electrical energy such as
`So
`of enormous difference of potential, and the
`have described, may be maintained at incan
`secondary S' thus becomes the source of the
`descence if the frequency and potential of the
`energy to be applied to the purpose of pro
`current be sufficiently high.
`-
`ducing light.
`would here state that by the terms “cur
`The light-giving devices may be connected
`rents of high frequency and high potential'
`55
`to either terminal of the secondary S. If de
`and similar expressions which I have used in
`sired, one terminal may be connected to a
`this description I do not mean, necessarily,
`conducting-wall W of a room or space to be
`currents in the usual acceptance of the term,
`lighted and the other arranged for connection
`but, generally speaking, electrical disturb
`of the lamps therewith. In such case the
`ances or effects such as would be produced in
`walls should be coated with some retallic or
`the secondary source by the action of the
`conducting substance in order that they may
`primary disturbance or electrical effect.
`have sufficient conductivity.
`It is necessary to observe in carrying out
`The lamps, or light-giving devices may be
`this invention that care must be taken to re
`an ordinary incandescent lamp; but prefer
`duce to a minimum the opportunity for the
`to use specially-designed lamps, examples of
`dissipation of the energy from the conductors
`which linave shown in detail it he draw
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`Momentum Dynamics Corporation
`Exhibit 1009
`Page 003
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`454,622
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`8)
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`Io
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`75
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`pole of the Source of current. The metallic
`ings. This lamp consists of a rarefied or
`lining S and the sheet in thus compose the
`exhausted bulb or globe which incloses a
`plates or armatures of a condenser.
`refractory conducting body, as carbon, of
`This invention is not limited to the special
`comparatively small bulk and any desired
`means described for producing the results
`shape. This body is to be connected to the
`hereinabove set forth, for it will be seen that
`Secondary by one or more conductors sealed
`various plans and means of producing cur
`in the glass, as in ordinary lanps, or is ar
`rents of very high frequency are known, and
`ranged to be inductively connected thereto.
`also means for producing very high poten
`For this last-named purpose the body is in
`tials; but I have only described herein cer
`electrical contact with a metallic sheet in
`tain ways in which I have practically carried
`the interior of the neck of the globe, and
`out the invention.
`on the outside of said neck is a second sheet
`What I claim is
`which is to be connected with the source of
`1. The improvement in the art of electric
`current. These two sheets form the arma
`lighting herein described, which consists in
`tures of a condenser, and by them the cur
`generating or producing for the operation of
`rents or potentials are developed in the light
`the lighting devices currents of enormous fre
`giving body. As many lamps of this or other
`quency and excessively high potential, sub
`kinds may be connected to the terminal of S
`stantially as herein described.
`as the energy supplied is capable of maintain
`2. The method of producing an electric cur
`ing at incandescence.
`irent for practical application, such as for elec
`In Fig. 3, b is a rarefied or exhausted glass
`tric lighting, which consists in generating or
`globe or receiver, in which is a body of car
`producing a current of encrmous frequency
`bon or other suitable conductor e. To this
`and inducing by such current in a working
`body is connected a metallic conductor f.
`circuit, or that to which the lighting devices
`which passes through and is sealed in the
`25
`are connected, a current of corresponding
`glass wall of the globe, outside of which it is
`frequency and excessively high potential, as
`united to a copper or other wire g, by means
`of which it is to be electrically connected to
`set forth. .
`-
`3. The method of producing an electric cur
`95
`one pole or terminal of the source of current.
`rent for practical application, such as for elec
`Outside of the globe the conducting-wires are
`tric lighting, which consists in charging a con
`protected by a coating of insulation h of any
`denser by a given current, maintaining an
`suitable kind, and inside the globe the sup
`intermittent or oscillatory discharge of said
`porting-wire is inclosed in and insulated by a
`condenser through or into a primary circuit,
`tube or coating k of a refractory insulating
`and producing thereby in a secondary work
`substance, such as pipe-clay or the like. A
`35
`ing-circuit in inductive relation to the pri
`reflecting-plate l is shown applied to the out
`mary very high potentials, as set forth.
`side of the globe b. This form of lanp is a
`4. The method of producing electric light
`type of those designed for direct electrical
`by incandescence by electrically or induct
`connection with one terminal of the source
`ively connecting a conductor inclosed in a
`of current; but, as above stated, there need
`rarefied or exhausted receiver to one of the
`not be a direct connection, for the carbon or
`poles or terminals of a source of electric
`other illuminating body may be rendered lumi
`energy or current of a frequency and poten- .
`nous by inductive action of the current there
`tial sufficiently high to render said body in
`on, and this may be brought about in sev
`eral ways. The preferred form of lamp for
`candescent, as set forth.
`-
`5. A system of electric lighting, consisting
`this purpose, however, is shown in Fig. 2.
`in the combination, with a source of electric
`In this figure the globel is formed with a cy
`energy or current of enormous frequency
`lindrical neck, within which is a tube or sheet
`and excessively high potential, of an incan
`I
`in of conducting material on the side and
`descent lamp or lamps consisting of a con
`over the end of a cylinder or plug of any
`ducting body inclosed in a rarefied or ex
`suitable insulating material. The lower edges
`hausted receiver and connected directly or
`of this tube are in electrical contact with a
`inductively to one pole or terminal of the
`metallic plate 0, secured to the cylinder , all
`source of energy, as set forth.
`the exposed surfaces of such plate and of the
`6. In a system of electric lighting, the com
`other conductors being carefully coated and
`55
`bination, with a source of currents of enormous
`protected by insulation. The light-giving
`frequency and excessively high potential,
`body e, in this case a straightstem of carbon,
`of incandescent lighting devices, each con
`is electrically connected with the said plate
`sisting of a conducting body inclosed in a
`by a wire or conductor similar to the wire f,
`rarefied or exhausted receiver, said conduct
`Fig. 3, which is coated in like manner with a
`ing body being connected directly or induct
`refractory insulating material k. The neck
`ively to one pole or terminal of the source of
`of the globe fits into a socket composed of an
`current, and a conducting body or bodies in
`insulating tube or cylinder p, with a more or
`the vicinity of said lighting devices con
`less complete metallic lining s, electrically
`connected by a metallic head or plate a with nected to the other pole or terminal of said
`a conductorg, that is to be attached to ono source, as set forth.
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`Momentum Dynamics Corporation
`Exhibit 1009
`Page 004
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`4.
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`454,622
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`7. In a system of electric lighting, the com
`bization, with a source of creats of enorainous
`frequency of excessively high potential, of
`ighting devices, each consisting of a con
`dicting body inclosed in a rarefied or ex
`halisted receiver and connected by conduct
`org directly or inductively with one of the
`te:DiCals of Said soutce, all parts of the con
`
`ductors internaediate to the said source and
`the light-giving body-being insulated and pro- E
`tected to prevent, the dissipation of the elec
`tric energy, as herein set forth.
`-
`NHKOA. TES.A.
`itnesses:
`-
`PARKER. W. PAGE,
`M. G. TRACY,
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`Momentum Dynamics Corporation
`Exhibit 1009
`Page 005
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