| [THE ARMATURE] | [221] to 228 |
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Definition—how continuous current is obtained—type ofarmature—comparison ring and drum armatures—why drum armature is theprevailing type—disc armatures—why disc armatures were abandoned.
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| [ARMATURE WINDINGS] | [229] to 256 |
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Preliminary considerations—winding diagrams and winding tables—lap andwave winding—angular pitch or spread of drum coils—parallel or lapwinding—series or wave winding—double-windings—Siemenswinding—objection to Siemens winding—chord winding—multiplexwindings—number of brushes required—number of armaturecircuits—equalizer rings—drum winding requirements.
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| [THEORY OF THE ARMATURE] | [257] to 282 |
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Current distribution in ring and drum armatures—connection ofbrushes—variation of voltage around the commutator—crossmagnetization; field distortion—remedies for fielddistortion—angle of lead—demagnetizing effect of armaturereaction—effect of lead—eddy currents; lamination—remedy foreddy currents—magnetic drag on the armature—smooth and slottedarmatures—comparison of smooth and slotted armatures—magnetichysteresis in armature cores—core loss or iron loss—deadturns—friction.
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| [COMMUTATION AND THE COMMUTATOR] | [283] to 302 |
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Period of commutation—commutating plane—normal neutralplane—neutral plane—plane of maximuminduction—commutation—position of thebrushes—sparking—effect of self-induction—construction ofcommutators—points relating to commutators—types ofcommutator.
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| [BRUSHES AND THE BRUSH GEAR] | [303] to 320 |
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Classification—gauze brushes—wire brushes—stripbrushes—carbon brushes—adjustment—comparison of copper andcarbon brushes—size of brushes—number—contact angle ofbrush— brush contact—drop in voltage at brushes—brushholders—brush rigging—multipolar brush gear.
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| [ARMATURE CONSTRUCTION] | [321] to 348 |
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Parts—shaft—core—slotted core—core laminations—corebolts—attachment to shaft—insulation of corediscs—teeth—advantages and defects of slottedarmatures—slotted cores; built upconstruction—ventilation—insulation of core—armaturewindings—construction of inductors—objection to copperbars—various windings: hand winding—evolute or butterflywinding—connectors—barrel winding—bastard winding—formerwinding—former coils—peculiarity of evolute coil—"straightout" coil—coil retaining devices—driving horns.
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| [MOTORS] | [349] to 388 |
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Definition—principles—propelling drag—essential requirementsof construction—the reverse electromotive force—hydraulicanalogy—action of current supplied to motor—armature reactionin motors—method of starting a motor— classes of motor;series, shunt, and compound—power of a motor—brake horsepower—mutual relations of motor torque and speed—speedregulation—series parallel controller—interpole motors.
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| [SELECTION AND INSTALLATION] | [389] to 406 |
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General conditions governingselection—construction—efficiency—adaptation of series andshunt motors—location—foundations—erection of dynamos andmotors—connecting up dynamos—marine generating set—beltclamp—belt lacing—belt speed—points relating to belts—geardrive—friction drive—electrical connections.
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| [AUXILIARY APPARATUS] | [407] to 430 |
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Switches—switch classification and construction—difficultyencountered in opening the circuit—various switches: knife,snap, and quick break types—fuses—circuit breakers: maximum,minimum, reverse current, maximum and reverse current, novoltage breaker—discriminating cut out—time limitattachments—rheostats—starting boxes—switchboards.
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