Nikola Tesla - Free-Energy Devices

POLYPHASE CURRENTS. 23manner, or alternately in opposition ;in the latter case a motorwith half the number of poles will result, and its action will becorrespondingly modified. The Figs. 15, 16, and 17, showthree different phases, the magnet coils in each circuit being connectedalternately in opposition. In this case there will be alwaysfour poles,as in Figs. 15 and 17 ;four pole projections will beneutral ;and in Fig. 16 two adjacent pole projections will havethe same polarity.If the coils are connected in the same mannerthere will be eight alternating poles, as indicated by the lettersn' s' in Fig. 15.The employment of multipolar motors secures in this system anadvantage much desired and unattainable in the continuous currentsystem, and that is, that a motor may be made to run exactlyat a predetermined speed irrespective of imperfections in construction,of the load, and, within certain limits, of electromotiveforce and current strength.In a general distribution system of this kind the following planshould be adopted. At the central station of supply a generatorshould be provided having a considerable number of poles. Themotors operated from this generator should be of the synchronoustype, but possessing sufficient rotary effort to insure their starting.With the observance of proper rules of construction it may beadmitted that the speed of each motor will be in some inverseproportion to its size, and the number of poles should be chosenaccordingly. Still, exceptional demands may modify this rule.In view of this, it will be advantageous to provide each motorwith a greater number of pole projections or coils, the numberbeing preferably a multiple of two and three. By this means, bysimply changing the connections of the coils, the motor may beadapted to any probable demands.If the number of the poles in the motor is even, the action willbe harmonious and the proper result will be obtained ;if thisis not the case, the best plan to be followed is to make amotor with a double number of poles and connect the same inthe manner before indicated, so that half the number of polesresult. Suppose, for instance, that the generator has twelve poles,and it would be desired to obtain a speed equal ^ to of the speedof the generator. This would require a motor with seven poleprojections or magnets, and such a motor could not be properlyconnected in the circuits unless fourteen armature coils would beprovided, which would necessitate the employment of sliding