GB200849A - Improvements in or relating to electric supply systems - Google Patents

Abstract

200,849. Drake & Gorham, Ltd., and Watson, A. H. St. C. Jan. 17, 1922. Systems depending on the use of two or more machines.-The load on the prime-mover of an electric supply system is maintained constant by the provision of a second machine, the output of which varies inversely as the output of the main generator. The second machine may at times run as a motor. A subsidiary machine B, Fig. 1 (Prov.), is provided with a field winding a<1> connected across the main dynamo A and an opposing field winding b in series with the load circuit of the dynamo A, so that the excitation of the machine B varies inversely as the load D on the generator A. The machine B may be provided with a series and a shunt winding. In the modification shown in Fig. 2, the machine B is connected in series with a load resistance C across the main dynamo A and is provided with a series field winding b. When the load D on the dynamo A is a maximum the voltage of the machine B is equal and opposite to that of the machine A and no current flows through the resistance C. As the load D is decreased the voltage of the machine B is decreased and currert is supplied to the resistance C. The output of the two machines A, B may be controlled by a regulator comprising a lever L, Fig. 1 (Comp.), controlled by a voltage coil M and a lever L<1> controlled by a voltage coil X and a voltage coil Y of smaller power than the coil X. The contacts on the levers L, L<1> control a winding on a relay R, the contacts of which control a resistance in the field-winding b.