CONTENTS

xvn

PAU B

rectifiers—Y connected three-phase rectifier—Delta connected
three-phase rectifier—Star connected quarter-phase rectifier—
Quarter-phase rectifier with independent phases—Ring con-
nected quarter-phase rectifier—Wave shapes and their discus-
sion—Six-phase rectifier.................250
144. Ring connection or independent phases preferable with a large
number of phases—Thomson Houston arc machine as con-
stant current alternator with three-phase star connected rectifier
—Brush arc machine as constant current alternator with
quarter-phase rectifiers in series connection........254
145. Counter e.m.f. shunt at gaps of polyphase ring connected
rectifier—Derivation of counter e.m.f. from synchronous mo-
tor—Leblanc's Panchahuteur—Increase of rectifier output with
increasing number of phases...............255
146. Discussion: stationary rectifying commutator with revolving
brushes—Permutator—Rectifier with revolving transformer—
Use of synchronous motor for phase splitting in feeding
rectifying commutator: synchronous converter—Conclusion . 257
CHAPTER XVI, REACTION MACHINES,
147. Synchronous machines operating without field excitation . . 260
148. Operation of synchronous motor without field excitation de-
pending on phase angle between resultant m.m.f. and magnetic
flux, caused by polar field structure—Energy component of
reactance.......................261
149. Magnetic hysteresis as instance giving energy component of
reactance, as effective hysteretic resistance........262
150. Make and break of magnetic circuit—Types of reaction
inachines—Synchronous induction motor—Reaction machine
as converter from d.-c. to a.-c...............263
151. Wave shape distortion in reaction machine, due to variable
reactance, and corresponding hysteresis cycles.......264
152. Condition of generator and of motor action of tho reactance
machine, as function of the current phase.........267
153. Calculation of reaction machine equation—Power factor and
maximum power....................268
154. Current, power and power factor—Numerical instance . . .271
155. Discussion—Structural similarity with inductor machine . . 272
CHAPTEE XVII. INTDUCTQU MACHINES.
156. Description of inductor machine type—Induction by pulsating
unidirectional magnetic flux...............274
157. Advantages and disadvantages of inductor type, with regards
to field and to armature..............-... 275
158. The magnetic circuit of the inductor machine, calculation of
magnetic flux and hysteresis loss.......,.....27(3