Large Motor Information

Discussion in 'Electronics Resources' started by shredability, Jan 28, 2014.

  1. shredability

    Thread Starter Member

    Apr 1, 2012
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    [​IMG]

    I just pulled a motor out of a large machine (Robot) and am trying to figure out specifically what type it is. It has three wires coming from the coils (red,blk,wht) and something that looks like a very primitive hall effect sensor on the back. The motor was connected to encoders, but they were not directly mounted on the back.

    I'm guessing brushless DC, something to this effect:
    [​IMG]

    Are there ways to probe it to get information from it? I'm not going to be able to use the old hall effect or encoders, does anyone know where I can get hall/encoder combos. I'm not worries about mounting config I can just do up a plate.

    -Ryan
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Is this an ECM motor from HVAC or similar application?
    Does it have P.M. rotor?
    Max.
     
  3. alfacliff

    Well-Known Member

    Dec 13, 2013
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    it is a brushless dc motor. the hall effect diodes are to sync the rotor position with the drive electronics. the hvac motors do not position like the robot motors, they are only for variable speed use. the brushless dc robot motor will position and hold its position as well.
     
  4. shredability

    Thread Starter Member

    Apr 1, 2012
    31
    0
    I don't think so, its from this puppy:

    [​IMG]

    The robot was built in 1988 if that helps
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    In that case it could be a BLDC or a AC sinusoidal, I would be surprised to see a BLDC on a robot, generally these are AC sinusoidal with absolute encoders, (not differential).
    But 1988, it could then be a BLDC.
    Either way, you need a BLDC drive, minimum.
    Modern motor do not use hall effect for commutation, the equivalent to hall pulses are on the encoder.
    Max.
     
  6. shredability

    Thread Starter Member

    Apr 1, 2012
    31
    0
    This machine had absolute encoders
     
  7. shredability

    Thread Starter Member

    Apr 1, 2012
    31
    0
    [​IMG]

    I figure something like this with IGBT's instead of BJT's. ARM cortex M-4 or ATmega32 depending on how much speed I need, completely optically isolate the power side from the controller/hall side.
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The hall spacing will depend the pole count of the motor, generally 4 pole to 8 pole.
    For 8 pole there is four electrical revolutions per mechanical revolution.
    Max.
     
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