(No Model.)

N. TESLA.

2 Sheets-Sheet 1.

REGULATOR FOR ALTERNATE OURRENT MOTORS.

No. 390,820,

Patented Dot. 9, 1888.

WITNESSES:

INVENTOR.

~~J~ BY ~~ ~. my.

~'974!4~~

~r.t£~~

ATTORNEYS,

N. PETERS. Phclo·Lilhogr.:pl>"r. W~sninston. O. C.

(No Model.)

2 Sheets-Sheet 2.

N. TESLA.

REGULATOR FOR ALTERNATE OURRENT MOTORS.

No. 390,820.

Patented Oot. 9, 1888.

v

WITNESSES:

INVENTOR.

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1i'~.=r;.T/~

BY

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~ea«. ~ bLlc&y. ATTORNEYS.

N. PETERS. Photo-Litoogr:.pt""r. \'Iashington. O. C

UNITED STATES PATENT OFFICE~ NIKOLA Tl£SLA, OF NEW YORK, N. Y., ASSIGNOR 'ro THE TESLA ELECTRIC COJUPANY, OF SAliIE PLACE.

REGULATOR FOR ALTERNATE-CURRENT MOTORS. SPECIFICATION forming part of Letters Patent No. 390,820, dated Octob"n' 9, 1888.

To all who])u it 1nay concern: Be it known that I, NIKOLA TESLA, a subject of the Emperor of Aust,l'ia, from Smiljan, Lika, bordel'conntryof Austria-Hungary, now 5 residing in New York, in the connty and State of New York, have invented certain new and 11sefl11 Improvemcnts in Regulators for Alternating-Current :Nlotors, of which the following is a specification, reference being had to the IO drawings accompanying and forming part of the same. JHy invention is an improvement ill system::; for the electric transmission of power; and it consists in a means of regulating the speeel anel IS power of the motor or motors. 'rhe system for use with which the invention is more particularly flesignctl is one in which the motors, or what may be in certain cases their equivalents-tbeeleetricaHransformcrs-havetwo01' 20 more independent energizing-circnits, which, receiving cnrrent from correspondingsonrces, act to set np a progressive movement or shiftiug of the magnetiC poles of the motors; bnt the invention is also applicable to other pur25 poses, as will hereinafter appeal'. I eml)loy the regulator for the purpose of \"arying the speed of these motors. '.rhe regulator proper consists ora forlll of converter or transformer with one elcment ca30 pable of movement with respect to the other, whel'ebytheinductiverelations may be altered, either manually or autornatically,for the purpose of varying the strength of the induced current. I prefer to construct this elevice in 35 snch manner that the induced or secondary element lllay be movable with l'espect to the other; anel the improvement, so far as relates merely to the construct,~on of .the device itself, consists, essentially, in the combination, with 4 0 two opposite magnetic poles, of an armature wound with an insulated coil and mounted on a shaft, whereby it may be turned to the desired extent within the field produced by the poles. The normal position of the core of the 45 secondary element is that in which it most completely closes the magnetic cil'cnit between the poles of the primary element, and hJ this position its coil is in its mosteiiecti\'c position for the inductive action upon it of t.he primary 50 coils; bnt by turning the movable core to . either side the induced cnrrents c1elivere