. The Street railway journal . of this controllerwere gotten out and put on the market. In 1891-2 considerable work was done in the direction ofusing series-parallel connection of the motors, for determiningwhether speed control in this manner was feasible. This workwas carried out in connection with the No. 3 motors. In theearly part of 1892 a series of tests was made, both in the shopand in service, with a pair of these controllers, and shortlyafterward this method of control was put on the market by theWestinghouse Company. The series-parallel method of con-trol soon became so thoroughly es
. The Street railway journal . of this controllerwere gotten out and put on the market. In 1891-2 considerable work was done in the direction ofusing series-parallel connection of the motors, for determiningwhether speed control in this manner was feasible. This workwas carried out in connection with the No. 3 motors. In theearly part of 1892 a series of tests was made, both in the shopand in service, with a pair of these controllers, and shortlyafterward this method of control was put on the market by theWestinghouse Company. The series-parallel method of con-trol soon became so thoroughly established that it was practi-cally the only street car control manufactured by the have been many modifications and improvements in theseries-parallel controller since first brought out by the com-pany, among them being the addition of the magnetic blow-out,but the drum construction placed on the platform has beenretained, except for very large equipments. Mention has already been made of the first rheostat made. t - .— - HMUl NO. 38 MOTOR ARMATURE by the Westinghouse Company for street car work, this con-sisting of concentric copper coils. This was soon supersededby a rheostat made of iron wire spirals in a supporting frameand covered with a heavy wire netting with a rather largemesh. This rheostat, on account of its appearance, was namedthe bird-cage type. The use of this rheostat was continuedfor a considerable period, but was then superseded by a rheo-stat made of iron strap wound in spirals on supporting number of these spirals were assembled together in oneframe. This was a more substantial rheostat than the bird-cage type, and was soon used almost exclusively. The adop-tion of the series-parallel control reduced the size of rheostat required, and thus to a certain extent simplified the problem ofits construction. One difficulty found with the early No. 3 motors was in un-balanced armature currents with two or more motors per armatures of
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
