116 



ALTERNATING (TltKENTS 



(150 to 750 r.p.m.); and the high-speed turbo-alternator (750 to 

 3,600 r.p.m.). 



FIG. 121. Pole piece of a 75 kv-a., 60-cycle, 377 r.p.m. alternator. 



The poles of practically all salient-pole generators have cores 

 made up of laminations, Fig. 121, in order to reduce pole-face 

 losses. (Vol. I, page 358.) In slow-speed machines, the poles are 



FIG. 122. 36-pole rotor with strip- wound coils. 



often bolted to a cast-iron spider, Fi<>;. 122, or they may be dove- 

 tailed to the spider in the manner indicated in Figs, 116 and 123, 



