GB190422817A - Improvements in and relating to Electric Power Transmitting Mechanism, applicable to Motor Vehicles and other similar purposes. - Google Patents

Abstract

22,817. British Thomson-Houston Co., and Hopps, B. Oct. 22. Dynamos, regulating.-Electric motors to drive motor vehicles &c. are supplied with current from a generator driven by a constant-speed internalcombustion engine or other prime-mover on the vehicle, the arrangements of the field circuits of the generator being such that a constant-watt output is obtained from the generator notwithstanding the load variations. In one form, in a compound generator with armature A, Fig. 1, the series field winding F is operative to assist the shunt coil only at starting and during periods of heavy load. When the voltage and load become established, the series winding is cut out of circuit, the resistance L inserted in the shunt circuit of the generator, and the resistance in the shunt circuit regulated to the load conditions by means of the suitably-proportioned solenoid-controlled resistance switch M operated by the current in the main generator circuit. A hand-operated rheostat G in the shunt circuit of the generator, or a switch to shunt some of the current through the solenoid M, may be used to control the ultimate speed of the vehicle. As the speed of the vehicle increases, the voltage at the generator terminals is automatically raised, and the current lowered so as to keep the output constant. In another modification, a simple shunt generator is used, the field winding B, Fig. 2, being excited from the separate exciter C driven from the same shaft as the main generator, the field being compound-wound, while the shunt winding may be energized by accumulators. The shunt winding D of the exciter is joined in series with the main generator circuit, so as to oppose the shunt winding E. In the modification shown in Fig. 3, the field of the simple shunt generator is excited by accumulators, and is connected in opposition to the armature C of a small auxiliary generator driven from the main shaft. In another modification, the accumulators may be omitted, and the shunt winding may be excited from its own terminals. In all these arraugements the ultimate speed of the vehicle may be controlled also by varying the speed of the prime mover.