INDEX 



Acyclic D.C. generators, reference 



to, 83 



Air-gap, density (see Flux density), 

 "equivalent," 117, 212, 337 

 length of, 119, 252, 325, 337 

 permeance, 116, 272, 336 

 Air, quantity of, required with 



forced ventilation, 112 

 Alternator, design sheets for 8,000 



k.v.a., 322 



three phase, output of, 247 

 Alternators, classification of, 238 



single-phase, 280, 321 

 Amortisseur windings (see Pole-face 



windings). 

 Ampere-conductors per inch (see 



Specific loading). 

 Ampere-turns, calculation of, on 



horseshoe magnet, 60 

 in dynamo field coils, 139, 187 

 in series winding (dynamo), 190 

 on armature (of dynamo), 78, 136 



(of alters ator), 249, 278, 345 

 on interpoles, calculation of, 174 

 per unit length in air, 21 

 " Apparent " developed voltage 



(A.C.), 287, 334 



Armature ampere-turns (see Ampere- 

 turns). 



coils, length of, 97, 261 

 conductors, current density in, 97, 



259 



insulation of (see Insulation), 

 losses in, 318 

 number of, 206 

 core, flux densities in, 104, 210, 



266, 330 



losses in, 100, 104, 266, 331, 356 

 net and gross length of, 103, 326 

 current, effect of, on flux distri- 

 bution, 135 



diameter (how determined), 77, 

 205 



Armature, m.m.f., 136, 274, 278 



in single-phase alternators, 280 

 reactance and reaction, 304 

 teeth (see Teeth), 

 windings, concentrated (A.C.), 



242 



distributed (A.C.), 242 

 double layer (A.C.), 255 

 duplex, 86 

 full pitch, 85 

 inductance of, 263 

 insulation of (see Insulation), 

 losses in, 90 

 multiple or lap, 86 

 multiplex, 86 

 resistance of, 97, 209, 260 

 series or wave, 86 

 short pitch (chorded), 85, 160 

 simplex, 86 



single layer (A.C.), 255 

 single-, two-, and three-phase, 



240 

 spread of (A.C.), 257; in single 



phase, 258 



Armatures, drum-wound, 84 

 ring-wound, 84 



temperature rise of, 107, 111, 267 

 ventilation of, 105, 261, 351 

 ARNOLD, DR. E., referred to, 141 

 Asynchronous A.C. generators re- 

 ferred to, 237 



B 



Balancing coils (see Pole-face wind- 

 ings). 



BEHREND, B. A., referred to, 307 

 B-H curves, 16, 17, 18, 215 

 Brown and Sharp gage, 34, 36 

 Brush contact resistance, 179, 226 



effect of, on commutation, 



147, 175 



pressure, usual, 179 

 width, as affecting commutation, 

 157, 162 



359 



