. Electric railway gazette . END CONNECTORS \lwmj FIG. 26. defect existed. The armature, however perfectly balanced,was out of electrical balance. That is, some of the coilsbeing obliged to lap over others, were longer than them,and hence had a higher resistance. Now, while the extraresistance of a few inches of wire is very small, it usuallyis a large percentage of the resistance of a coil, and is,therefore, a serious matter, as we shall see in anotherchapter. When the brushes are set correctly to commutatea coil of a certain resistance, they are incorrectly set tocommutate a coil of
. Electric railway gazette . END CONNECTORS \lwmj FIG. 26. defect existed. The armature, however perfectly balanced,was out of electrical balance. That is, some of the coilsbeing obliged to lap over others, were longer than them,and hence had a higher resistance. Now, while the extraresistance of a few inches of wire is very small, it usuallyis a large percentage of the resistance of a coil, and is,therefore, a serious matter, as we shall see in anotherchapter. When the brushes are set correctly to commutatea coil of a certain resistance, they are incorrectly set tocommutate a coil of any other resistance. Hence, a com-mutator on one of these unsymmetrical armatures is liableto a certain amount of incurable sparking and problem of how to make an armature winding that. OUTER LAYERFIG. 27. shall not only have coils of the same resistance, but thesame shape and size as well, has been successfully met byseveral designers. Many have partially, and a few wholly,met this requirement. Now consult Fig. 26. It is naturalto suppose that it is proper to connect each conductor on toits opposite. However, this is the very thing that wemust not do. Every conductor on the one side of thearmature needs a return on the other side. Hence, we maynot connect No. 1 on to No. 13, but on to No. 14 or , according as we desire on right or left handed , if we separate Fig. 26 into two figures, drawing onlyoue half of the armature connections across the ends in eachdiagram, we see that in each of the two diagrams, and 28, there are no cross wires. But taken together,there are many crossed wires. Now, if we so wind the wire as to have all of the uncrossed wires of each dia-gram come in separate layers, we need to have the armaturehead only two layers th
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1895
