BLDC back emf?

Discussion in 'General Electronics Chat' started by arjun.bhasi, Oct 18, 2013.

  1. arjun.bhasi

    Thread Starter New Member

    Oct 18, 2013
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    Why does BLDC motor has got a trapezoidal back emf?:confused:
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    The shape of the magnetic pole pieces/regions will affect the waveform.
     
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  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Because a BLDC motor uses a trapezoidal wave form to drive it.
     
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  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The BLDC motor can also be driven by PWM square wave, the BEMF generated is a 3 phase sinusoidal voltage.
    With the BLDC two windings are energised at any one time, the AC sinusoidal motor is constructed exactly the same way but uses a 3 phase sinusoidal for power.
    http://www.youtube.com/watch?v=oFI7VW6WGR4
    Max.
     
    Last edited: Oct 18, 2013
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