CONTINUOUS-CURRENT WINDINGS 153 



have this same pitch of 141 at the front end ; but the front end 

 pitch, so far as relates to the interconnection of the coils, will be 



2,7=143. 

 Thus y (mean) = 142, y/= 143, yb = 141. 



A development of a portion of this winding is shown diagram- 

 matically in Fig. 180, the front connections of the component turns 

 not being shown ; and the three face conductors forming one side 

 of a single (four turn) coil being represented by a single radial 

 line. This conforms to the diagram which is found most convenient 

 in practice, in representing such a winding. 



A little reflection will show that the labour of preparing a 

 complete diagram showing each individual turn would generally 

 be prohibitive, and furthermore, that it would not be conducive to 

 clearness. It is preferable to make the above indicated mental 

 reservation, and comply with the more simple practice correspond- 

 ing to the diagram of Fig. 180. 



MULTIPLEX WINDINGS. 



As already stated, both two - circuit and multiple - circuit 

 windings may be multiplex. As multiplex windings are not to 

 be recommended except in special cases, no great amount of space 

 will be devoted to their consideration. 



MULTIPLE-CIRCUIT MULTIPLEX WINDINGS. 



Fig. 181 is a diagram of an eight-pole multiple-circuit duplex 

 winding. The winding shown is doubly re-entrant, that is to 

 say, it consists of two entirely independent conducting systems 

 completely insulated from one another. These are represented 

 by black and red lines in the diagram. The winding has 300 

 face conductors, 150 belonging to each winding. The front end 

 pitch is 35, and the back end pitch is 39. In multiple-circuit 

 multiplex windings there will be a number of independent 



windings equal to the greatest common factor of - and m, where 



a 



C is equal to the number of face conductors, and m is equal to 

 the number of windings. In the present instance we are con- 

 sidering a duplex winding. Hence m = 2. ' is equal to 150. 







The greatest common factor of 150 and 2 is 2. Hence the winding 

 is a doubly re-entrant duplex winding. The pitches must be 



