Help needed in driving Bipolar Stepper motor

Discussion in 'General Electronics Chat' started by shohaib111, Nov 4, 2010.

  1. shohaib111

    Thread Starter New Member

    Aug 4, 2010
    11
    0
    Help needed in driving Bipolar Stepper motor
    i am trying to drive bipolar stepper motor, i have got no special bipolar stepper motor driver IC, instead i m using a Power supply which can give current upto 1A,
    first of all, i found resistances between different terminals,
    which found to be...
    RED-------9.7 Ohm-----yellow
    orange----9.7 Ohm-----blue

    Now i connected RED with +5V and yellow to blue to gound,
    But i am unable to get rotation, but instead i get jerks only,
    and motor produces SOUND like high frequency SssssssEEEEEEEEEEEEEEEEEEEEEE

    So please guide, what i am doing wrong,
    I have tried much, but in vain...........
    2 paint files are available for better description of what i am doing
    Note:
    motor is from a old floppy drive,
    5V, 1.8 degree motor
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    A 4-wire bipolar stepper motor requires two H-bridges plus logic in order to step the motor.

    They are pretty hard for a beginner to understand and use. Unipolar (5- and 6-wire) stepper motors are much easier to work with.

    If you still have the circuit board that was in the floppy drive, look up the part numbers on the ICs; you will probably find one that is a bipolar stepper driver.
     
  3. shohaib111

    Thread Starter New Member

    Aug 4, 2010
    11
    0
    I have already tried and run successfully the unipolar stepper(6 wire), which came from a printer.
    so after that i came to this bipolar, which came from a floppy drive...
    I just want to drive it, some way or the other, but for a better understanding, i wanted to watch it moving in steps when i supply it power,
     
  4. shohaib111

    Thread Starter New Member

    Aug 4, 2010
    11
    0
    I just want to drive it, some way or the other, but for a better understanding, i wanted to watch it moving in steps when i supply it power
    and i didn't understand, what do you mean by two H-Bridges,
    i have uploaded a paint file, which shows, what i am trying to do, and by seeing that you will probably spot the error.....

    as already mentioned that motor just gets a little jerk, and does nothing else, after that jerk, no rotation at all.....

    as already mentioned, I am using no driver IC for larger current, but instead i am using a Power supply, which can give current of upto 1A, and i think for this small motor (5V, 1.8 degree) 1A is enough.
     
  5. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,007
    1,530
    Maybe reading this will help; http://www.cs.uiowa.edu/~jones/step/

    A stepper will only make one step/jerk with out using a step driver. they do not rotate with out the driver.
     
    Last edited: Nov 6, 2010
  6. shohaib111

    Thread Starter New Member

    Aug 4, 2010
    11
    0
    what do u mean by Dual H-Bridge, 2 h-bridges??
    do u mean that there are 2 poles so we need one H- Bridge for each Pole??
    i was started on thinking like this because 4 transistors were required for a single H-Bridge like:
    SEE the attached link........
    Driving Bipolar Stepper Motors

    and if there are 2 poles, then we will require 8 Transistors, means 2 H- Bridges
    Am i right??
    if i am right, then i am clear in the problem...
     
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