THE ALTERNATOR 



103 



coil or coil-group per pole. The winding of Fig. 102 may be ob- 

 tained from Fig. 103 by swinging coil B into the plane of coil A 

 and coil D into the plane of coil C. 



One slot per pole is seldom found in practice, as the surface 

 of the armature is not economically used, and in addition a poor 

 voltagr wave results. Figure 104 shows the winding of Fig. 103, 

 except that there are now two slots per pole instead of one. This 

 is al a two-layer winding, as there are two coil sides per slot, 

 placed one above the other. 



Plan View 

 showing Single 

 Range 



Single-phase, Single-range Spiral Winding 



Fl Fl F 



(O 



Barrel-type Winding which can n-pl.-i.-i- Spin] Winding of (a) 



105. 



Instead of making tin- coils lap our another, M is dour ir 



104, the winding may !>< placed on the armature in the manner 



shown in l-'in. In".. Tin- ifl '-ailed a s/nnil winding. It will he 



ed that in this part ieiilar winding the cil> ihem-rlvrs have 



a pitch less than ISO rlr.-f ri.-al Bpa <>8. Notwithstanding 



\\\\< toner pitch, the windiir. oonaidered u havimz the 



prnp, -uhar In | t'rari j, ,r,-d-pii .-h \\ [ndlOg, Tip 



conductors may b< d l-\ l.ai-rel-typc end 'ions. 



