242 



ARMATURE CONSTRUCTION 



In tapping this winding for single-phase alternating current, 

 we may first connect the lead from conductor No. 7 to one 

 collector ring, then we progress around the winding until we 

 have taken in one-sixth of the total number of conductors, i.e. 

 twelve, which occurs when we reach conductor No. 31, at which 

 point another tapping is made to the same collector ring. 



FIG. 283. Winding for a Six-phase Rotary Converter, Six-circuit Single-winding 

 with 108 Conductors, Six Poles. Pitch : Front, 19 ; Back, 17. 



After taking in twelve other conductors, another tapping 

 is brought out after having traversed conductor No. 55. In 

 progressively taking in one-sixth of the conductors we pass over 

 one-third of the periphery, or a distance of twice the pole pitch. 

 Thus if we take one tap out at conductor No. 7, .the next tap 

 to the same ring occurs at conductor No. 31, and the pitch of 



72 



conductors between one tapping and the next is 24, or -- x 2, 



6 



or, generally, twice the number of conductors per pole. The same 



