. A textbook on electric lighting and railways. International correspondence schools, Scranton, Pa. v. 1-3, 5 . he commutator bar immediately in line with it and thelong lead would go to the bar as nearly diametrically oppo-site as possible. This would be bar 50. The next coilwould drop into slots 2 and ;?7 and its leads would go tobars 2 and 51. This is a rule that holds good on any arma-ture having 99 slots and 99 coils where the four poles are on 24 ELECTRIC RAILWAYS. 75 the horizontal and vertical, as, for example, on the G. or 1,200 motors. To make it hold yood on armatureshaving 99
. A textbook on electric lighting and railways. International correspondence schools, Scranton, Pa. v. 1-3, 5 . he commutator bar immediately in line with it and thelong lead would go to the bar as nearly diametrically oppo-site as possible. This would be bar 50. The next coilwould drop into slots 2 and ;?7 and its leads would go tobars 2 and 51. This is a rule that holds good on any arma-ture having 99 slots and 99 coils where the four poles are on 24 ELECTRIC RAILWAYS. 75 the horizontal and vertical, as, for example, on the G. or 1,200 motors. To make it hold yood on armatureshaving 99 coils, 99 bars, hut only 33 slots, it is only neces-sary to count off as if each coil had its own slot or as ifthere were no slots at all. Vor instaiu-e, suppose there areonly 3.) slots; then, one sitle of coils /, J, and ./ will he inslot 1: 4, -7, and ! in slot -■; 7, in slot -/; and so on,so that the other sides of coils J, J, and ■/, which formerlyfell into slots 2(1, 27, and 28, when there was a slot for eachct)il, must now drop into slot ■>; the other sides (jf coils ,^, o,. and I) in slot 10; and so on. The short lead of coil 1 goes tobar 1 and the long lead to bar GO, as before. After one coilis installed, the others follow the same course. Fig. 55 shows the connections for an armature having99 slots and 99 coils, with the pole pieces on the diagonal. Itwill be noticed that in both cases, the brushes fall in thesame place. In Fig. 55, however, the lead out of slot 1,instead of going to bar 1, directly opposite, goes to bar 87,obtained by counting to the left 14 bars, including bar 1;99 is not divisit)!e by S, so that this is as nearly one-eightha circumference as it is possible to get. Since the lead 76 ELECTRIC RAILWAYS. §24 coming out of slot 1 is shifted |- X 99 bars to the left, so mustthe lead out of slot 26 be shifted the same amount, so thatinstead of going into bar 50, it goes into bar 37, which is14 bars to the left, counting bar 50. In practice, the
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectelectri, bookyear1901
