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DC motor example — Parallax Forums

DC motor example

Robot FreakRobot Freak Posts: 168
edited 2007-10-05 19:38 in General Discussion
I can't find an example explaining how to connect a DC motor to the Javelin.
Does anyone know something about it? (except a motor controller)

Thanks a lot!

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-07-02 22:54
    Hello,

    Typically you’d use a Motor Controller such as the HB-25 or at minimum an H-Bridge to control the DC Motor. It really depends on what kind of control you’re looking for. Do you need speed control? Reverse capability?

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    Chris Savage
    Parallax Tech Support
  • Robot FreakRobot Freak Posts: 168
    edited 2007-07-03 07:48
    I'm looking for Forward - Off - Reverse. Speed control is not necessary.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-07-03 17:07
    Hello,

    You could do that using just an H-Bridge or even using two Relays (One SPST and one DPDT). If you use relays be sure to drive them with a transistor. Take care.

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    Chris Savage
    Parallax Tech Support
  • Robot FreakRobot Freak Posts: 168
    edited 2007-08-04 10:21
    I changed my mind, I also need the speed control, so two relays won't work.
    I need to control 4 DC motors, using the HB-25 it will cost $200.

    Is it also possible using a PWM signal? (I see the PWMPAL can control 4 DC motors? or is that one-direction?)

    Thanks!
  • Steve64Steve64 Posts: 11
    edited 2007-08-16 16:15
    Try National LMD18200 H-Bridge controllers.· Cost about $12.00 in onesies from Digikey. You can control each one with 2 Javelin pins and one PWM VP.

    Steve
  • Robot FreakRobot Freak Posts: 168
    edited 2007-08-17 09:34
    Thanks for your reply!

    It's a great controller, but I've got a motor that takes 7.2V and 200mA no load, 3.80A locked shaft.
    This controller starts at 12V...
  • Peter VerkaikPeter Verkaik Posts: 3,956
    edited 2007-08-17 14:20
    How about a L298?
    http://info.hobbyengineering.com/specs/SOLARBOTICS-KCMD-L298_Compact_motor_driver.pdf

    See also this thread:
    http://forums.parallax.com/showthread.php?p=573128

    regards peter
  • Robot FreakRobot Freak Posts: 168
    edited 2007-08-17 16:34
    Thanks,
    does it still need extra components for speed control?

    Edit: never mind, a PWM signal.

    Post Edited (Robot Freak) : 8/18/2007 9:46:22 AM GMT
  • GeorgeCollinsGeorgeCollins Posts: 132
    edited 2007-10-05 19:38
    I have had a good experiences using Super Rooster RC Car speed controllers (try Tower Hobbies) and the PWM java object. They are dog simple because you can just plug them in like a servo and they work well with 12 volt motors. They are also a little more durable than other possible choices. That isn't the cheapest solution but is has worked well for me.
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