. Electrical world. y besafely stated that the efficiency of such a system is undoubtedlysuperior to the system of rheostatic control even when reinforcedby a series-parallel system. Therefore in point of economy of thecar equipment itself, there are advantages in favor of the system, andfurthermore it is capable of returning power to the line not at acritical speed but at any and all speeds, thereby providing an electricbrake of most economical type. In all other traction systems, withthe exception of a few which have not been particularly practicable,all the power employed in getting the cur
. Electrical world. y besafely stated that the efficiency of such a system is undoubtedlysuperior to the system of rheostatic control even when reinforcedby a series-parallel system. Therefore in point of economy of thecar equipment itself, there are advantages in favor of the system, andfurthermore it is capable of returning power to the line not at acritical speed but at any and all speeds, thereby providing an electricbrake of most economical type. In all other traction systems, withthe exception of a few which have not been particularly practicable,all the power employed in getting the current of the car under head-way is subsequently wasted in heat at the brake shoes. In the WardLeonard system, however, the accumulated energy of the car istransformed into electricity and fed back into the line, and moreoverthe system of braking is ideal. It is well known by traction engi-neers that the proper method of braking is to apply just sufficientbraking power to prevent the wheels from skidding on the Fig. 2.—Gener.\l View of Locomotive. unit arrangement, switching large currents, or with a system oftransformers and voltage regulators, which are the modern alterna-tives, to obtain the results that can be obtained with the WardLeonard system, the latter certainly merits some consideration. This system as now employed at the Oerlikon Works in Switzer-land, where it is imdergoing a rigid test, consists of an induc-tion motor adapted to receive and transform single-phase currentsinto mechanical power. This is transmitted to a dynamo of appro-priate capacity by direct connection, and thence the current is dis-tributed to the motors by means of the Ward Leonard control. Torefresh the memory of those who are not familiar with this well-known system, it may be stated that in controlling a motor for vari-able speeds by the Ward Leonard system, the motor is given constantfield and the voltage is varied by varying the field on the generatingdynamo from zero to a maximum,
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
