Nikola Tesla Articles
Electricity - Dynamo Electric Machines
The object of this invention is to provide an improved method for regulating the current of dynamo electric machines. A1 and B1 are the brushes of the main circuit, and C an auxiliary brush. The working circuits D extends from the brushes A1 and B1, and contains electric lamps in series or in multiple arc. M M1 represent the field helices, the ends of which are connected to the main brushes. The shunt wire C1 extends from the auxiliary brush C to the intermediate point X in the circuit of the field helices. H represents the commutator with the plates of ordinary construction.
A current will flow over the auxiliary brush, to or from the commutator, according to the relative position of the brushes. If, for instance, the commutator space between the brushes A1 and C, when the latter is at the neutral point, is diminished, a current will flow from the point Y over the shunt C1 to the brush B1, thus strengthening the current in the part M1, and partly neutralising the current in the part M; but if the space between the brushes A1 and C is increased, the current will flow over the auxiliary brush in an opposite direction, and the current in M will be strengthened, and in M1 partly neutralised.
By combining with the brushes A1 B1 and C any known automatic regulating mechanism, the current developed can be regulated in proportion to the demands in the working circuit. The respective cores of the field magnet are subjected to the neutralising or intensifying effects of the current in the shunt through C1, and the magnetism of the cores will be partially neutralised or the point of greatest magnetism shifted, so that it will be more or less remote from, or approaching to, the armature, and hence the action of the field magnets on the armature will be correspondingly varied.
Claims: (1) The combination with the commutator, having two or more main brushes and an auxiliary brush, of the field helices, having their ends connected to the main brushes, and a branch or shunt connection from an intermediate point of the field helices to the auxiliary brush, and means for varying the relative position upon the commutator of the respective brushes, as set forth; (2) the combination with the commutator and the main brushes, and one or more auxiliary brushes, of the field helices in the main circuits, and one or more shunt connections from the field helices to the auxiliary brushes, the relative positions upon the commutator of the respective brushes being adjustable for the purpose set forth. - No. 2975. March 2nd, 1886. 8d