. The Street railway journal . n parallel. No attempt was made to equalize thearmatures, as there was apparently but little unbalancing inthese machines, probably due to the very large air gaps. These early motors had the gears enclosed in cases. Themotor was double reduction. The general type of this motorwas very similar to that of the other systems in commercialoperation at the same time. The controller consisted of a wooden drum with metal stripson the outside. The general appearance was similar to theSprague controller, but the steps were principally for rheo-static control instead of com
. The Street railway journal . n parallel. No attempt was made to equalize thearmatures, as there was apparently but little unbalancing inthese machines, probably due to the very large air gaps. These early motors had the gears enclosed in cases. Themotor was double reduction. The general type of this motorwas very similar to that of the other systems in commercialoperation at the same time. The controller consisted of a wooden drum with metal stripson the outside. The general appearance was similar to theSprague controller, but the steps were principally for rheo-static control instead of commutated fields. The rheostats put out with these early motors are worthyof mention. These rheostats were peculiar in the fact that theywere made of copper wire instead of high resistance ma-terial. Three coils were used. Each coil was made in theform of a thin cylinder. The three coils were of different sizes,so that they could be assembled in concentric form with airspaces between. The reason for adopting this design was that. NO. 4, OR GEARLESS MOTOR a very simple construction was permitted, as the coils werewound of commercial cotton-covered wire on the simplest kindof former and were then taped. It was considered that whilethe resistance of copper was comparatively low, yet the heatconductivity of such wires was very great, and that a veryconsiderable rheostatic capacity could be obtained without ex-cessive weight. Such a rheostat was, of course, costly, prin-cipally on account of the material in it. This rheostat gavefairly satisfactory results and was practically as good a pieceof apparatus as many other parts of the system. On accountof the cost of the material in this coil, steps were soon takento design a cheaper rheostat, and various forms were gottenout for test, some of which soon superseded the copper-coilrheostats. Shortly after the No. 1 motor was gotten out, the No. 2 mo-tor was also put on the market. This was very similar to theNo. 1, except that it was for na
Size: 2154px × 1160px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
