BLDC Motor

Discussion in 'General Electronics Chat' started by assaf_malki, Aug 27, 2012.

  1. assaf_malki

    Thread Starter New Member

    Aug 27, 2012
    1
    0
    Hey guys,

    I have a BLDC Motor which I try to control using Xilinx FPGA.

    It's a sensor-less motor and I try to close a loop using the Encoder.

    My signals to the Motor are 3 Halls signals, PWM, Brake and direction.

    The signals are going through the following component

    http://www.google.co.il/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCkQFjAA&url=http%3A%2F%2Fwww.allegromicro.com%2F~%2FMedia%2FFiles%2FDatasheets%2FA3932-Datasheet.ashx&ei=AUg7UPK3NqGk0QXU6YHYCQ&usg=AFQjCNHvQ0cn-MFbhwnHGWcarssfM9HI-A&sig2=3gGAPHprHfl9IvWdN39tVw&cad=rja

    and at the end I get the 3 phases which go to the motor.

    So far I've managed to rotate it by closing a loop with the encoder which by that, I get the halls (I chose the halls using the Datasheet I posted above).

    I gave it a specific PWM and it rotates.

    My first problem is that I actually need to give it the first push (by Hand) for it to start rotating, how can I avoid it?

    Another thing is that I only have 6 selection for the halls and by that I divided the space (360 degrees). However I don't understand how can I put it in a middle point, between the flux created and a magnet?

    Another thing, what is the relation between the PWM and speed?

    Thanks a lot.

    Assaf.
     
  2. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    Last edited: Aug 30, 2012
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