VOLT PHASE CURRENTS.

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followed in such cases. These cores are wound with coils n, whichare connected in the same circuit, either in parallel or series, andsupplied with an alternating or a pulsating current, preferablythe former, by a generator e, represented diagrammatically. Be-tween the cores or their polar extensions is mounted a cylindricalor similar armature e, wound with magnetizing coils g, closedupon themselves.

The operation of this motor is as follows: When a currentimpulse or alternation is directed through the coils n, the sectionsB B of the cores, being on the surface and in close proximity tothe coils, are immediately energized. The sections c, on the otherhand, are protected from the magnetizing influence of the coilby the interposed layers of iron b b. As the magnetism of b bincreases, however, the sections c are also energized; but theydo not attain their maximum strength until a certain time subse-cpient to the exhibition by the sections b b of their maximum.Upon the weakening of the current the magnetic strength of b bfirst diminishes, while the sections c have still their maximumstrength; but as b b continue to weaken the interior sections aresimilarly weakened, b b may then begin to exhibit an oppositepolarity, which is followed later by a similar change on c, andthis action continues, b b and o may therefore be considered asseparate field-magnets, being extended so as to act on the arma-ture in the most efficient positions, and the effect is similar tothat in the other forms of Tesla motor—viz., a rotation or pro-gression of the maximum, points of the field of force. Anyarmature—such, for instance, as a disc—mounted in this fieldwould rotate from the pole first to exhibit its magnetism to thatwhich exhibits it later.

It is evident that the principle here described may be carriedout in conjunction with other means for securing a more favor*able or efficient action of the motor. Tor example, the polarextensions of the sections c may be wound or surrounded byclosed coils. The effect of these coils will be to still moreeffectively retard the magnetization of the polar extensions of c.