. Modern mechanism, exhibiting the latest progress in machines, motors, and the transmission of power, being a supplementary volume to Appletons' cyclopaedia of applied mechanics . for 200 incandescent lamps. 199 could be turned out without materially affecting thebrilliancy of the remaining one. The data of this machine are as follows:Weight, 2,886lbs.; length, G2-5 in.; breadth, 53 in.; height, 25-75 in.; resistance of external circuit, 0-4ohm ; resistance of arma-ture, -008 ohm; resistanceof field-coils, 24-1 ohm ;E. M. P., 67 volts; num-ber of revolutions permin., 960; diamiter ofarmature-
. Modern mechanism, exhibiting the latest progress in machines, motors, and the transmission of power, being a supplementary volume to Appletons' cyclopaedia of applied mechanics . for 200 incandescent lamps. 199 could be turned out without materially affecting thebrilliancy of the remaining one. The data of this machine are as follows:Weight, 2,886lbs.; length, G2-5 in.; breadth, 53 in.; height, 25-75 in.; resistance of external circuit, 0-4ohm ; resistance of arma-ture, -008 ohm; resistanceof field-coils, 24-1 ohm ;E. M. P., 67 volts; num-ber of revolutions permin., 960; diamiter ofarmature-wire. 0-24 ratio of armature toshunt resistance in thiscase was therefore 1 to3,000. This high rateis, however, rarely at-tained. Fig. 56 illustrates theThom>ion - Houston Dij-iiamo for incandescentlighting. It resembles ingeneral design the arc-machine; its distinguish-ing feature, however, isthe method employed forobtaining constant poten-tial automaticiilly withoutthe use of external resist-ances. This is accom-plished l\v means of a setof series - coils placedat an inclined positionaround the armature, asshown, which react uponthe armature so as to Fi<r. 57. maintain Fig. .56.—Thomson-Houston dynamo. the point of commutation fixed at all loads,shows the Eickemeyer Dynamo, which claims attention on account of its novel construction. The object soughtto be obtained by the inventoris to concentrate the full excit-ing force of the fiold-coils uponthe armature-core, and he ac-complishes this by encirclingthe armature-core with an ex-citing helix, and then inclosingtlie whole within an iron latter is provided withpole-faces, and thus completesthe magnetic circuit which in-cludes tlie armature-core andthe cheeks. Fig. 58 shows a longitudi-nal section of one form of tliemachine, and Fig. 59 a trans-verse section with the armatureremoved. It will be seen thatthe shell of iron inclosing thearmature is built up of a lami-nated mass of sheet-iron, towhich end-p
Size: 1702px × 1468px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade189, booksubjectmechanicalengineering
