Stepper motor driving using 89C51 to det high RPM

Discussion in 'Embedded Systems and Microcontrollers' started by ssureshtronics, Apr 2, 2008.

  1. ssureshtronics

    Thread Starter New Member

    Sep 8, 2006
    8
    0
    :I'm using L297 and Dual H-Bridge MOSFET drivers to drive my Bipolar Stepper motor. The task is to rotate the motor in high RPM. When I am trying to increase the speed of rotation by increasing the clock i/p frequency which fed to L97, Motor makes heavy noise and strucking. but when I'm rotating in lower speed i'm done well.
    whats the solution to rotate at high speed. I doubted on quick decaying of the motor current. Is there any possibilities to quick discharge the current. I tried by fly-wheeling diodes and frequency jittering. Advice me anyother mathod. Current rating of the motor is 5A. and Operating voltage is 50 Volt.
    Thanks for perfect solution:)
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    My experience with steppers is that they need to have the driver frequency start low and get ramped up over time to the highest frequency.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Check the datasheet for your stepper motor.

    Usually, "Starting step rate max" and "Slewing step rate max" are given.

    You must not exceed the "starting step rate max" when starting the motor from a stop.
    If your motor has a load with high rotational inertia (like a flywheel) then you may have to start it at a much lower step rate.

    As Beenthere mentioned, then you can increase the stepping rate up to a maximum of what was specified for the "slewing step rate max".

    The torque that the stepper motor can produce steadily decays as the rotational speed increases, and will drop off rapidly as the motor approaches the "slewing step rate max". The actual maximum slewing rate of your stepper motor will be reduced by the static and dynamic loads that it is driving.
     
  4. ssureshtronics

    Thread Starter New Member

    Sep 8, 2006
    8
    0
    Hi r u there? now
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Yes, I am here now. ;)

    The forums are not "real-time", although sometimes responses to a question can come very quickly. Post your question, and if it's a decent one, someone will get back to you at some point in time.
     
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