INDKX jr.;; 



Ribbon wound field coil ..................................... 7;j 



Rotary converter ......................................... ; ;r,7 



Rotor, of an induction motor ............................ 



Scott connection of transformers ............................. 402 



Series generator, characteristics of a .......................... \:>,\ 



Series motor, characteristics of and use ................... 1 ">s, 352 



Shunt generator, characteristics of ............................ I ;;_' 



motor .............................................. 1 ;, i 



Shunt, used with series field winding .......................... 108 



Single-phase induction motor ................................ 347 



series motor .................................... 101 



compensating winding for ............ 356 



commutation of ..................... 358 



use of resistance leads ................ 359 



Skin effect in solid conductors ................................ 211 



Slot in armature core, shape of ............................... 46 



Solution of problems on a-c. circuits .......................... 225 



Sparking at commutator due to brushes in wrong position ....... 439 



insufficient brush pressure ....... 439 



open circuited coil .............. 440 



over-loaded armature ........... 439 



poorly fitted brushes ........... 439 



rough surface ................. 436 



short circuited coil ............. 439 



unequal air gap ................ 440 



unequal brush spacing .......... 440 



vibration of machine ........... 439 



Speed of a motor, effect of variation in line voltage on ........ 167 



Speed, no-load, of a motor, calculation of ................ 



Speed control of motor by field variation . 



by multiple voltage supply lim> . . 

 of induction motor ....................... 



of railway motors ....... 



Speed-load curves for different types of motors . . . 



Spider, armature ..................................... 



commutator ......................... 



Split phase method of starting an induction motor . . . 



Split pole synchronous converter ........................... 



Starting a machine, precautions to be observed ............ 



Starting rheostat for a motor .................... - ........... ^ 



" Step-down" and "step-up" transformers .......... 



