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stepper and ULN2003 Help — Parallax Forums

stepper and ULN2003 Help

BladerunnerBladerunner Posts: 25
edited 2005-03-19 00:59 in BASIC Stamp
Hi
Help.
I am new at this... I am using a ULN2003 to drive a stepper. I've got is moving etc. but the ULN2003 gets very hot, and the stepper is warm. I must have something connected wrong. Also the 12v connection is warm????
See attached circuit ,I have it set up with out the pot.


Thanks

BR
stepperCircuits.gif
501 x 545 - 12K

Comments

  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-03-18 19:51
    Your stepper may be drawing more current than the ULN2803 can handle without a heat sink.

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    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • BladerunnerBladerunner Posts: 25
    edited 2005-03-18 19:55
    Oh
    So the heat sink would go on the ULN2003?
    Attached is the stepper info


    Thanks for your help

    BR
    pdf
    pdf
    155432.pdf
    36K
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-03-18 19:56
    You can indeed get a heatsink for the ULN2803. Also, you may need to put current limiters between your ULN outputs and the stepper.

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    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • JonathanJonathan Posts: 1,023
    edited 2005-03-19 00:37
    BR,

    You can also tie outputs of the ULN2003 together to increase the current limitations. This is one of the handiest features of the chip.

    Jonathan

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • BladerunnerBladerunner Posts: 25
    edited 2005-03-19 00:59
    Hummm
    Thanks for the info but how do I do this with the ULN2003?

    Thanks
    BR
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