CONTENTS ix 



CHAPTER X 



MM 



I. Regulation of alternators and transformers 81. Bchn-Eschenburg and 

 Kapp's method 82. Kapp's diagram 88. Algebraical method of 

 determining drop 84. Rothert's ampere-turn method 86. Analysis of 

 armature self-inductance into two components 86. Experimental deter- 

 mination of two components of armature reactance 87. Potier's method 

 of predetermining the regulation of an alternator .... 151-162 



CHAPTER XI 



88. Resistance measurements of alternating-current machinery! 89. Insula- 

 tion tests 90. Experimental determination of equivalent impedance of 

 transformer 91. Transformer efficiency tests 92. Separation of core 

 losses 93. Heating test of transformer 94. Ageing of transformer core 

 95. Determination of open-circuit and short-circuit characteristics of 

 alternator 96. Hopkinson efficiency test 97. Determination of no- 

 load losses 98. Determination of total losses 99. Retardation method 

 of determining losses 100. Heating test of alternator. Mordey's and 

 Behrend's methods 101. Goldschmidt's method 102. Hobart and 

 Punga's method 103-179 



CHAPTER XII 



103. Assumptions underlying approximate theory of induction motors 104. 

 Leakage coefficients 105. Behaviour of motor independent of number 

 of turns in rotor winding. Rotor slip 106. Induction motor replaced by 

 equivalent transformer 107. Torque of induction motor 108. Study 

 of transformer equivalent of induction motor. Vector diagram 109. 

 Transformation of vector diagram. Deduction of circle diagram 110. 

 Construction for slip and torque 111. Case of negligible primary resist- 

 ance. Heyland's circle diagram 112. Effect of resistance in (1) stator 

 and (2) rotor 113. Use of starting resistances 114. Effect of stator 

 core loss. Efficiency of motor 180-197 



CHAPTER XIII 



115. Experimental data required for construction of circle diagram. Deter- 

 mination of hysteresis loss 116. Short-circuit test 117. Construction 

 of torque circle and slip line. Scales for torque and slip 118. Applica- 

 tions of circle diagram 119. Brake tests. Soames' brake 120. Air- 

 friction dynamometer 121. Eddy-current brakes 122. Measurement 

 of slip. Stroboscopic methods 123. Methods applicable to slip-ring 

 rotors 124. Measurement of friction loss 125. Efficiency tests. 

 Method of Meunier, Sumpner, and Weekes 126. Alexanderson's method 

 127. Heating test 128. Induction motors with large starting 

 torque 198-218 



