SOME SPECIAL ROTATING MACHINES

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SOME SPECIAL ROTATING MACHINES

• FRACTIONAL HORSE POWER MOTORS
• MASS PRODUCTION
• MOSTLY BASED ON BASIC PRINCIPLES
• UNIVERSAL SERIES MOTOR
• SINGLE PHASE INDUCTION MOTOR
• RELUCTANCE MOTOR
• STEPPER MOTOR

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UNIVERSAL SERIES MOTOR
LIKE DC SERIES MOTOR, MAGNETIC CIRCUIT IRON
SHEETS
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CHARACTERISTICS OF USM
BY AC POWER SUPPLY IS THE BEHAVIOR WORSE
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SPEED CONTROL OF USM

• EXAMPLE OF USE HOUSEHOLD APPLIANCES
• VACUUM CLEANER
• HAIR DRYER

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SINGLE PHASE INDUCTION MOTOR
ONE PHASE CANNOT PRODUCE ROTATING FIELD
STATOR like by 3phase ROTOR squirrel cage
BUT WHEN ONCE ROTATES, IT PRODUCES TORQUE
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TORQUE-SPEED CURVEof single-phase induction motor
SUBSTITUTION OF ONE PULSATING FIELD BY TWO
ROTATING FIELDS
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FUNCTION OF AUXILIARY PHASE
ELIPTIC FIELD CAPACITOR only for start
for permanent run
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SHADED POLE
FOR SMALL STARTING TORQUE
The current in short circuited ring produces own
flux and thus makes field deformation
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RELUCTANCE MOTORS
FOR SMALL SYNCHRONOUS MOTORS example CLOCK
ROTOR starting bars squirrel cage
Magnetic non-symmetry in d and q axes shape of
torque curve like by salient pole machines
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STEPPER MOTOR
FOR PRECISE POSITIONING WITHOUT FEED BACK LOOP
STATOR poles excited by DC pulses ROTOR
permanent magnet od DC windings
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TORQUE BY STEPPER MOTOR