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ELECTRICAL MACHINERY 



Such a winding is shown in Fig. 45. A four-pole 

 machine having 24 slots and one turn per coil is shown. 

 It is evidently a lap winding as one coil " laps over " its 

 neighbor. The proper position for the brushes is fixed by 

 locating a coil in which no e.m.f. is generated and then 

 placing one brush on the two adjacent segments to which 



FIG. 45. A Typical Lap Winding, having Two Coil Sides per Slot 



the coil ends are attached. The other three brushes are 

 located symmetrically with respect to this one. 



Pitch. The term pitch is frequently used in connection 

 with armature winding. The pitch of a coil is measured 

 by the number of inductors between coil sides. The pitch 

 so determined is usually called the back pitch; the front 



