ALTERNATING-CURRENT WINDING 167 



Now there is a second way in which we can connect up the 

 conductors of Fig. 198, and still arrive at a simple and symmetrical 

 grouping. If, instead of connecting at the back end conductor No. 1 

 to GA, we connect it to No. 2A, and 3 to 4A instead of to 2A, also 5 to 

 6 A instead of to 4A, we obtain the result shown in Fig. 201. Here 

 we have a set of three elements, each consisting of four conductors 

 connected in pairs at the back end of the armature. Fig. 201 should 

 be compared with Fig. 199, directly above it. 



If now we connect conductor 2A to IA, 4A to SA, and 6A to 5A, 

 also 2 to 3 and 4 to 5, we arrive at the winding shown in Fig. 

 202, where the ends of conductors 1 and 6 remain as the terminals 

 and are connected to the collector rings or other terminals. 



Fig. 202 has been placed under Fig. 200, and these two 

 windings, which are equivalent to one another electrically, should 

 be compared. 



To bring out more clearly the difference between these two 

 types of windings, we have in Figs. 203 and 204 taken a 6-pole 

 winding but with four conductors per pole. 



Fig. 203 is drawn after the same manner as the winding in 

 Fig. 200, and Fig. 204 after the manner of the winding in Fig. 202. 



It will be first noted that in Fig. 203 the whole of the inner 

 and outer circumference (corresponding to the front and back ends 

 of the armature) is occupied by connectors between the various 

 conductors ; in Fig. 204, however, only half of the inner and outer 

 circumference is occupied by these connectors. 



This is clearly brought out by Figs. 205 and 206, which 

 represent diagrammatically the back ends of the two armatures 

 as they would actually appear with their windings in place. 



There are a few other points which may be observed in connec- 

 tion with these two styles of winding. 



Fig. 203, it will be seen, consists of six nearly similar elements 

 connected together, while Fig. 204 consists of only three similar 

 elements (compare with Figs. 199 and 201). 



It will be convenient to designate the element of each winding 

 a " coil," and Figs. 207 and 208 show respectively the coils of the 

 windings of Figs. 203 and 204. 



Now, since both these windings are 6-pole, we have in Fig. 203 

 one coil per pole or one pole per coil, and, in Fig. 204, one coil per 

 pair of poles or one pair of poles per coil. 



This brings us to our first broad division for alternating-current 

 windings. Windings having one coil per pole we designate whole- 

 coiled windings (the whole of the poles being subtended by coils). 



