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Why we used capacitor in the fan ?

  1. Apr 30, 2016 #1
    One of my classmate asked me a question that Why we used capacitor in the fan ? I gave her the answer but she said the answer in not fully appropriate ! Any one give me proper explanation of this question ?
  2. jcsd
  3. Apr 30, 2016 #2


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    Staff: Mentor

    Hi 7see. smiley_sign_welcome.gif

    Had you dismantled the fan, in order to discover the capacitor?

    Is this a fan powered from the AC mains electricity?

    What was the answer you gave?
  4. May 1, 2016 #3


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    Staff: Mentor

    Welcome to the PF.

    Is this question for schoolwork? We need to hear your reply before we can be of help on this.

    Please all other posters hold off replying until we get the OP's reply. Thanks. :smile:
  5. Jun 7, 2016 #4


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    One thing I have learned over the years here on PF is to not hold your breath with first time posters. Without knowing if the fan motor is AC or DC we cannot know which answer is appropriate.
  6. Jun 7, 2016 #5


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    It's been longer than a month since the OP was last seen on the forum and I believe it's unlikely that he will reply in this thread.
    For ceiling fans (and other fans that operate directly on ac mains), the motors used are single phase induction motors. Capacitor creates a phase difference between the currents in starting and running windings of the motor, hence giving rise to a rotating magnetic field in the rotor. The rotating magnetic field will drag the rotor along with it, just like in case of a 3-phase induction motor. This motor is also called a CSCR (Capacitor Start Capacitor Run) motor.
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