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Publication numberUS428057 A
Publication typeGrant
Publication dateMay 13, 1890
Publication numberUS 428057 A, US 428057A, US-A-428057, US428057 A, US428057A
InventorsNikola Tesla
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pyromagneto-electric generator
US 428057 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

(No Model.)


PYROMAGNETO ELECTRIC GENERATOR. No. 428,057. Pzit ented May 13, 1890.

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NIKQLA TESLA, or New YORK, N. IYJ, AssIeNoR or ONE-HALF To. en ance v r. men, or ENGLEWOOD, NEW JERSEY;


srncmcatrron forming part of Letters Patentflo. 428,057, dated my 13,1890. Original application filed In as, 1887; else so. 239,481. mean a thit'application 'fllod my as, 1889, steam. 812.069-

(Noni To all whom it may concern:

Be it known that I, NIKOLA TESLA, a subj ect of the Emperor of Austria-Hungary, from Smiljan, Lika, border country of Austria-Hungary, residing at New York, in the county and State of New York, haveinvented certain new and useful Im provemcuts in Electrical Generators, of which the following is a specification. This application is a division of an application filed by me May 26, 1887,Serial No. 239,481.

This invention is an improved form of' electrical generator based upon the following well-known laws: electrical energy is developed in any conductis ing-body by subjecting such body to a. varying magnetic influence, and, second, that the magnetic properties of iron or other magnetic substance may be partially or entirely destroyed or caused to disappear by raising it to .a certain temperature, but restored and caused to reappear by again lowering its temperature to acertain degree. These laws may be applied inthe production of electrical currents in many ways, the principle of whichis. 2 5 in all cases the same-via, to sub ect a conductor to a varying magnetic influence, producing such variations by the application of heat, or, more strictly speaking, by the application or action of a varying temperature upon the source of the magnetism. This principle of operation may be illustrated by a siln-fl ple experiment: Place end to. end, and preferably in actual contact, a permanently-magnetized steel bar and a strip or bar of. soft 3 5 iron. Around the end of the iron bar or plate Y wind'a'ooilo'f insulated wire Then apply to the iron between the coilandthe steel bar a flame or-other source of heat which will be capable of raising that'portion of the iron to 40 an orange-red, ora temperature of about 600 centigrade. When this condition is reached, the ironsomewhat suddenlyloses its magnetic properties, if it be very thin, and the same elfects produced as though the iron had been moved away from the magnet or the heated I section had been removed. This change-of condition, however, is accompanied by a shift in g of the magnetic lines, or, inother words by a variation in the magnetic influence to wh ph First, that electricity orthe coil is exposed, and a current in the'coil 5c is the result.- --Then remove the flame or in any other way reduce. the temperature of the iron. The lowering of its temperature is accompanied' by a return of its magnetic prop erties, and another change of magnetic con- 5 5 ditions occurs, accompanied by a current in an opposite direction in the coil. The same operation may be repeated indefinitely, the effect upon the ,coil being similar to that which would follow from moving the magnet-- i zed bar to and from the end of the iron bar The device forming the subject of my present invention. is an improved means of obtaining this result, the features of novelty in 6 which theinvention resides being, first, theemployment of an artificial cooling device, and,

second, inclosing the source of heat and that portion of themagnetic circuit exposed to the heat and artificially'cooling the/said heated part. These improvements are applicable generally to the generators constructed on the plan above described-that is to say, I may use an artificial cooling device in conjunction with .a'variable or varied or uniform source of heat. I prefer, however, to employ a uni- 'f0rm heat.

In the drawingsI have illustrated a device constructed in accordance with my invention.

Figure. 1 is'a central vertical longitudinal section of the complete apparatus. Fig. 2 is a cross-section of the magnetic armature-core of the generator. I a Let A represent ,a' rnagnetized by an armature-core composed of a casing or shell'B inclosing a number of-hollcw iron 'tubes 0. Around this core are wound the conductors E E, to form the coils in which the currents are developed. In the circuits on of these'coils are-translating devices, as FF. Dis a furnace or closed fire-box, through which the central portion of the core B extends. Above the lire-is aboiler K, contaim ing water. The flue L fromthe fire-box may 5. extend up through the boiler. p G isa water-supply pipe, and H is thesteamexhaust pipe, which communicates with all core or per maneii't ina'gnet the poles of which are bridged the tubes in the armature B, so that steam escaping from the boiler will pass through said tubes.

In the steam-exhaust pipe H is a valve V, to which is connected the lever I, by the move ment oftwhich the said valve is opened or closed. In such aease as this the heat of the. fire may be utilized for other purposes after to plied to heating the core 13.1 There are special advantages in them ing device, in that the metal of the core B is not so quickly oxidized. Moreover, the difference between the temperature of the-apgas or fluid be applied as the'cooling medium, may be increased or decreasedat will, whereby the rapidity of the magnetioichanges or fluctuations may be regulated.

is concerned,,the specificconstrnction ot the. apparatus is largely immaterial; however, claim in this. application, broadly,

- theapplieation of a variableheat to vary the magnetic conditions of a field of -foree in which" 'aninduced conductor isconta'in'ed.

P1 3 1116; 0i avcool plied heat and of the steam, air, or whatever In so far as my present invention, broadly,

I do-not,

What lclaim is 1. In an electrical generator, the combination, with a magnetized core or body and a conductor within the field of force produced thereby, of an inclosed source of heat applied to a portion of saidcore, and an artificial cooling device for reducing the temperature of the heated portionthereof, asset forth. as mnchof it as may be needed has been ap- 2. The combination, with a magnetized core 3 5 ul body ands conductor under the influence thereof, of an inelosed source of heat applied to a portion of said core, means for bringing a cooling gas or fluid in contact with the heated portion of the core, and means for con- 46- trolling. the admission of the same.

3. Thecombinatiomwitha magnetizedcore containing passages or channels, and coils wonn'd thereon, of means for applying heat to aportion of the core, and; a connection with a boiler for admitting steam into the channelegas set fortln NIKOLA TESLA.



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