Describe the main features of an AC electric motor

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Describe the main features of an AC electric motor

  • Synchronous
    • Has a rotor and stator
    • Similar to DC
    • Uses slip ring instead of split ring
    • Coils around core produces AC current
    • Polarity changes with current which gives a constant rotation
  • Induction
    • Rotor
      • Squirrel cage (copper bars attached to rings) encased in iron (laminated)
      • Eddy currents induced by changing magnetic field and flow from one end to the other
      • They produce an opposing magnetic field which is attracted and dragged along by the initial field
    • Stator
      • External electro magnet which produces the changing magnetic field
      • 3 phase version has 3 sets of coils surrounding the rotor which creates torque with a rotating field.