Patent Notes - Tesla's System of Multiphase Distribution

As is frequently the case, inventions are exploited and worked commercially before the issuance of the patents thereon, and not infrequently much injustice is done to the inventor by reason of the fact that the public is in ignorance of the date of the filing of the application. A striking instance of this character is the patent issued to Mr. Tesla on Dec. 13, 1892, No. 487,796, entitled "System of Electrical Transmission of Power."

While most of the features embodied in this patent are now well known in the art, the fact that the application was filed as far back as May 15, 1888, shows that even at that remarkably early date Mr. Tesla's ideas on the subject were clearly defined. The underlying principle embodied in this patent is to adapt the Tesla system to the type of alternating machinery now in general use. Thus there are described various methods of obtaining the required phase difference with ordinary multipolar alternators, by winding or coupling machines in various ways, together with other features whereby a single generator may run a number of motors either at the same speed as its own or all at different speeds.