48

INVENTIONS OF NIKOLA TESLA.

duee in the diagonally opposite portion a corresponding impulsein the opposite direction; hence portions of the current willneutralize one another.

As before stated, the mechanical construction of the devicemay he greatly varied; but the essential conditions of the princi-ple will be fulfilled in any apparatus in which the movement ofthe elements with respect to one another effects the same resultsby varying the inductive relations of the two elements in a man-ner similar to that described.

It may also be stated that the core e is not indispensable to theoperation of the regulator; but its presence is obviously bene-ficial. This regulator, however, has another valuable propertyin its capability of reversing the motor, for if the coil f be turned

J

Fig. 37.

through a half-revolution, the position of its convolutions rela-tively to the two coils cc and to the lines of force is reversed, andconsecjuently the phases of the current will be reversed. Thiswill produce a rotation of the motor in an opposite direction.This form of regulator is also applied with great advantage toMr. Tesla’s system of utilizing alternating currents, in which themagnetic poles of the field of a motor are progressively shiftedby means of the combined effects upon the field of magnetizingcoils included in independent circuits, through which pass alter-nating currents in proper order and relations to each other.

In Fig. 37, let p represent a Tesla generator having two inde-pendent coils, p' and p", on the armature, and t a diagram of a