364 



INDEX 



S 



Saturation curve for alternator, 302, 



306, 310, 340, 355 

 for dynamo, 189, 190, 228 

 Self-induction, not different from 



other induction, 155 

 Series field winding, 190, 192, 231 



or wave, winding, 86 

 Short-circuit current of alternators, 



252, 308, 354 

 Short pitch armature windings, 85, 



160 

 Shunt field current, usual values of, 



192 



Shunt winding- calculation (dyna- 

 mos), 191, 231 

 with two sizes of wire, 42 

 Simplex armature windings, 86 

 SIMPSON'S rule, 122, 217 

 Single-phase alternators, 280, 321 

 Size of wire, calculation of, in mag- 

 net coils, 41 



Sketches, importance of neat, 4 

 "Skull cracker," 64 

 Slot, dimensions of, in alternator, 



259 



in dynamo, 92, 93, 207 

 insulation (see Insulation of arma- 

 tures), 

 leakage flux, calculation of, 160, 



284 



effect of, on commutation, 149 

 "equivalent," 161, 164, 285 

 in alternators, 281 

 pitch (.definition), 92 

 Slots, number of, 93, 260 

 Space factor (definition), 39; (val- 

 ues), 40 

 Sparking at brushes, prevention of, 



175, 225 

 Specific heat, 47 

 Specific loading (definition), 74 



values for alternators, 250, 325 



for dynamos, 76 



Speeds, usual (dynamos), 81; (alter- 

 nators), 241 

 Spread of winding, 258 

 Star connection, 244 



STEINMETZ, DR. C. P., referred to, 



141 



S.W.G. wire table, 35 

 Symbols, list of, xi 



use of, 2 

 Synchronous A.C. generators (see 



Alternators). 



Teeth, dimensions of (dynamos), 92, 



208; (alternators), 259 

 flux density in, 104, 119, 122, 197, 



209 

 losses in, 102, 196, 211, 233, 318, 



331 



number of, 93, 260 

 strength of rotor, 336 

 taper, losses in, 196 



m.m.f. calculations for, 122 

 Temperature, internal, of magnet 



coils, 45 



rise of alternator field coils, 300 

 of armatures, 107, 112, 212, 267, 



357 



of circular lifting magnets, 67 

 of commutator, 181, 227 

 of dynamo field coils, 193, 232 

 of iron-clad coils, 46 

 of magnet coils, 44, 47, 56, 62 

 of totally enclosed motors, 236 

 Third harmonic, effect of Y and A 



connections on, 246 

 THOMPSON- RYAN, referred to, 170 

 Three-phase generators (see Alter- 

 nator). 

 Time, value of, in engineering work, 



64 

 Tooth saturation (comparison D.C. 



and A.C.), 271 



Tractive force (magnetic pull), 29 

 of cylindrical short-stroke mag- 

 nets, 50 



Tube of induction, 14 

 Turbo-alternator, design sheets for 



8,000 k.v.a., 322 



Turbo-alternators, output of mod- 

 ern, 320 



(rotor construction), 270 

 (usual speeds), 242, 320 



