The Inventions, Researches and Writings of Nikola Tesla

CHAPTER II.

A NEW SYSTEM OF ALTERNATING CURRENT MOTORS AND TRANSFORMERS.

The current section of this volume deals with polyphase currents and the inventions by Mr. Tesla made known thus far, in which he has embodied one feature or another of the broad principle of rotating field poles or the resultant attraction exerted on the armature. It is needless to remind electricians of the great interest aroused by the first announcement of the rotating field principle, or to dwell upon the importance of the advance from a single alternating current to methods and apparatus that deal with more than one. By way of introducing this subject, I must note that this volume is in no way intended to be polemical or controversial. It may be pointed out, however, that Mr. Tesla’s work has not been fully understood or appreciated to date. To many readers, it is believed, the analysis of what he has achieved in this department will be a revelation, while it will simultaneously illustrate the beautiful flexibility and range of the principles involved. It will be seen that, as suggested, Mr. Tesla did not stop at a mere rotating field, but dealt broadly with the shifting of the resultant attraction of the magnets. It will be seen that he went on to evolve the “multiphase” system with many variations; that he demonstrated the broad idea of motors employing currents of differing phases in the armature while using direct currents in the field; that he first described and developed the idea of an armature with a body of iron and coils closed upon themselves; that he worked out both synchronizing and torque motors; that he explained and illustrated how machines of ordinary construction could be adapted to his system; that he employed condensers in field and armature circuits; and that he investigated the fundamental principles, testing, approving, or rejecting every detail that inventive ingenuity could suggest.