dsPIC33FJ256GP710 ac motor speed controll

Discussion in 'The Projects Forum' started by simplextibi, Feb 10, 2014.

  1. simplextibi

    Thread Starter New Member

    Feb 10, 2014
    1
    0
    Hi

    I would like to ask if someone has a simple way of controlling 2 pieces of 20W ac 220V 2 wire motors using this dsPIC33?

    I been trying to figure out how to control them using a triac circuit for each but no luck

    Also can you somehow sense the load on them without the 3rd wire?

    I am new to this and would like to do a home project of ventilation


    thank you
     
  2. Experimentonomen

    Member

    Feb 16, 2011
    331
    46
    You need a single phase variable frequency drive. Though a simple variac usually works well enough on smaller fan motors like this.
     
  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
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  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,542
    2,369
    If you want rpm control via Triac, you need a zero cross detection circuit, to get an idea look at Fairchild AN-3006 app note.
    Also Google zero cross detection.
    Max.
     
  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    That's good advice, but you don't always need closed loop control of TRIACS on an AC motor.

    For small power motors with a reasonably constant load (like fans) you can just drive the TRIAC with pulses and get a bit of a hit and miss type effect.

    If you have RPM feedback to the PIC it will work quite well.
     
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