FIGURE 7-1 Incandescent lamps: (a) high wattage lamp; (b) parts of the lamp. [(a) Courtesy of Litetronics.] Dale R. Patrick Electricity and Electronics:

FIGURE 7-1 Incandescent lamps: (a) high wattage lamp; (b) parts of the lamp. [(a) Courtesy of Litetronics.]

Dale R. PatrickElectricity and Electronics: A Survey, 5e

Copyright ©2002 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458

All rights reserved.

(a)

FIGURE 7-1 continued Incandescent lamps: (a) high wattage lamp; (b) parts of the lamp. [(a) Courtesy of Litetronics.]




(b)

FIGURE 7-2 Operating principle of a florescent lamp: (1) filament glows when ac current flows through it; (20 when the starter opens, the ballast discharges to ionize the mercury (Hg) atoms; (3) ultraviolet radiation is given off by Hg atoms; (4) visible light is produced.




FIGURE 7-3 Circuit for a fluorescent lamp.




FIGURE 7-5 Mercury vapor lamps: (a) cutaway view of a mercury vapor lamp; (b) commercial mercury vapor lamp. [(b) courtesy of Philips Lighting Co.]




(a)

FIGURE 7-5 continued Mercury vapor lamps: (a) cutaway view of a mercury vapor lamp; (b) commercial mercury vapor lamp. [(b) courtesy of Philips Lighting Co.]




(b)

FIGURE 7-6 Sodium vapor lamp.




FIGURE 7-7 Resistance heating element (Courtesy of Williamson Co.)




FIGURE 7-8 Principle of induction heating.




FIGURE 7-9 Dielectric (capacitive) heating.




FIGURE 7-10 Basic parts of a dc motor.




FIGURE 7-11 Motor principle: (a) no current flows through rotor conductor; (b) direction of circular magnetic fields around the motor conductors when current flows; (c) compression points produced at A and B when current flows through rotor conductors-causing rotation.




FIGURE 7-12 Right-hand motor rule.




FIGURE 7-12 continued Right-hand motor rule.




FIGURE 7-13 Dc motor operating characteristics.




FIGURE 7-14 permanent magnet dc motor: (a) pictorial; (b) schematic.




FIGURE 7-14 continued permanent magnet dc motor: (a) pictorial; (b) schematic.




FIGURE 7-15 Series-wound dc motor: (a) pictorial; (b) schematic.




FIGURE 7-16 Shunt-wound dc motor: (a) pictorial; (b) schematic.




FIGURE 7-17 Field rheostat used to control dc motor speed. As Rheostat resistance increases, field current decreases, causing magnetic field strength to decrease and motor speed to increase.




FIGURE 7-18 Reversing the direction of rotation of dc motors.




FIGURE 7-18 continued Reversing the direction of rotation of dc motors.




FIGURE 7-19 Three-phase ac induction motor. (Courtesy of Westinghouse Electric Corp.)




FIGURE 7-20 Operational principle of a three-phase ac induction motor.




FIGURE 7-21 Diagram of a three-phase ac synchronous motor.




FIGURE 7-22 Methods of starting three-phase as synchronous motors: (a) auxiliary dc motor/generator used to accelerate the motor; (b) squirrel-cage or damper windings placed in the rotor.




FIGURE 7-23 Universal motor: (a) pictorial; (b) schematic.




FIGURE 7-24 Operation of a single-phase ac induction motor.




FIGURE 7-25 Squirrel-cage rotor: (a) internal construction; (b) assembled rotor.




FIGURE 7-26 Spilt-phase ac induction motor. (Courtesy of Dayton Manufacturing Co.)




FIGURE 7-27 Operation of a split-phase ac motor: (a) two-pole motor with single-phase as applied; (b) motor with two-phase ac applied; (c) motor with three-phase ac applied.




FIGURE 7-27 continued Operation of a split-phase ac motor: (a) two-pole motor with single-phase as applied; (b) motor with two-phase ac applied; (c) motor with three-phase ac applied.




FIGURE 7-27 continued Operation of a split-phase ac motor: (a) two-pole motor with single-phase as applied; (b) motor with two-phase ac applied; (c) motor with three-phase ac applied.




FIGURE 7-28 Split-phase ac motor: (a) schematic; (b) waveforms.




(a)

FIGURE 7-28 continued Split-phase ac motor: (a) schematic; (b) waveforms.




(b)

FIGURE 7-29 Capacitor-start ac motor: (a) cutaway view; (b) schematic diagram. [(a) Courtesy of Dayton Electric Manufacturing Co.]




(a)

FIGURE 7-29 continued Capacitor-start ac motor: (a) cutaway view; (b) schematic diagram. [(a) Courtesy of Dayton Electric Manufacturing Co.]




FIGURE 7-30 Waveforms of a capacitor-start ac motor.




FIGURE 7-31 Other types of capacitor motors: (a) capacitor-start, capacitor-run motor; (b) permanent capacitor motor.




FIGURE 7-32 Shaded-pole ac induction motor.




FIGURE 7-33 Operating principle of a shaded-pole ac motor




FIGURE 7-34 Synchro systems: (a) schematic diagram; (b) circuit-R1 and R2 are rotor connections and S1, S2, and S3 are stator connections.




FIGURE 7-34 continued Synchro systems: (a) schematic diagram; (b) circuit-R1 and R2 are rotor connections and S1, S2, and S3 are stator connections.




(b)

FIGURE 7-35 Servomotor. (Courtesy of Superior Electric Co.)




FIGURE 7-36 Dc stepping motor construction. (Courtesy of Superior Electric Co.)




FIGURE 7-37 Stator coil placement of stepping motor: (a) one set of stator coils-rotor can move in either direction; (b) two sets of stator coils-rotor will move in a clockwise direction.




FIGURE 7-38 Dc stepping motor rotor construction. (Courtesy of Superior Electric Co.)




FIGURE 7-39 Block diagram of a motor control circuit.




FIGURE 7-40 Pushbutton switches. [(a) Courtesy of Cutler-Hammer Co. (b) courtesy of Furnas Electric Co.]




(a)

FIGURE 7-41 Limit switches.




(b)

FIGURE 7-42 Fuses and circuit breakers: (a) fuses with holders; (b) internal construction of a circuit breaker. [(a) Courtesy of Cooper Industries; (b) courtesy of Heinemann Electric.]




(a)

FIGURE 7-42 continued Fuses and circuit breakers: (a) fuses with holders; (b) internal construction of a circuit breaker. [(a) Courtesy of Cooper Industries; (b) courtesy of Heinemann Electric.]




(b)

FIGURE 7-43 Manual motor starter. (Courtesy of Furnas Electric Co.)




FIGURE 7-44 Magnetic motor starter. (Courtesy of Furnas Electric Co.)




FIGURE 7-45 Control center. (Courtesy of Russelectric Inc.)




FIGURE 7-46 A start-stop pushbutton control circuit with overload protection (one-line diagram).




FIGURE 7-47 Motor-control circuit.




Documents

FIGURE 7-1 Incandescent lamps: (a) high wattage lamp; (b) parts of the lamp. [(a) Courtesy of Litetronics.] Dale R. Patrick Electricity and Electronics: