Dc motor

Discussion in 'General Electronics Chat' started by nandha_vikram, Aug 19, 2010.

  1. nandha_vikram

    Thread Starter New Member

    Aug 14, 2010
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    sir, i m interesting in motor design,

    stepper motor have a high holding torque... can we design a DC brush motor having the same holding torque which have a stepper motor..

    thank u sir.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    A conventional DC motor is designed to rotate continuously. The motor has a maximum torque at stall, but that is not the same as a stepper motor's holding torque - the DC motor wants to turn from the held position and the stepper wants to hold it's position.
     
  3. BillB3857

    Senior Member

    Feb 28, 2009
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    Full servo systems using DC motors have as much holding torque as they have rotating torque. The velocity loop, coupled with the position loop, provides current to cause the motor to resist any rotation, unless commanded to do so. Typical DC servo loops actually induce an amount of AC to the motor in order to keep it "limber" and ready to respond to any instantaneous commanded move. This AC is usually produced by introducing a small amount of cross-firing of the SCRs .
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    And to think I used to work with servos....
     
  5. BillB3857

    Senior Member

    Feb 28, 2009
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    Just a little "brain freeze", Beenthere?;)
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    Yes, or maybe I'm just getting too literal in interpreting questions.
     
  7. BillB3857

    Senior Member

    Feb 28, 2009
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    You did cover your backside in your first response when you said, "Conventional motors........." However, almost any motor, other than induction motors, with the right support behind it can fill the bill.
     
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