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Stepper motors and the Propeller Pro. Dev. Board's L293D 4-ch driver — Parallax Forums

Stepper motors and the Propeller Pro. Dev. Board's L293D 4-ch driver

DRMorrisonDRMorrison Posts: 81
edited 2014-07-23 21:52 in Propeller 1
Hello all,

I'm testing a bipolar stepper motor that I have using the L293D that is attached to the PPDB. I was able to get the motor to work, but the IC
gets a little hot due to the fact it's running at the rated current limit of 1A.

Does anyone have a suggestion for a different IC to run this stepper motor? It's a 4-wire, bipolar (two coils).

Daniel

Comments

  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2014-07-23 19:57
    DRMorrison wrote: »
    Hello all,

    I'm testing a bipolar stepper motor that I have using the L293D that is attached to the PPDB. I was able to get the motor to work, but the IC
    gets a little hot due to the fact it's running at the rated current limit of 1A.

    Does anyone have a suggestion for a different IC to run this stepper motor? It's a 4-wire, bipolar (two coils).

    Daniel

    Without a doubt I'd recommend the L6470, here's a link to my project page which has a link to the L6470 website and a couple of youtube videos I did at the time as well.
  • DRMorrisonDRMorrison Posts: 81
    edited 2014-07-23 20:24
    Thank you Peter,

    I did find an error in my code that was causing the over current situation. I've fixed it, and now the current draw is half of what it was. Within the specs
    of the L293D. I will look at your suggestion of the L6470.

    I've looked at your board and am impressed. I guess that you are not using a Propeller? I can't get mine to spin that fast. Wow.

    Thank you, Daniel
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2014-07-23 20:33
    DRMorrison wrote: »
    Thank you Peter,

    I did find an error in my code that was causing the over current situation. I've fixed it, and now the current draw is half of what it was. Within the specs
    of the L293D. I will look at your suggestion of the L6470.

    I've looked at your board and am impressed. I guess that you are not using a Propeller? I can't get mine to spin that fast. Wow.

    Thank you, Daniel

    My post in the youtube page:
    Published on Mar 22, 2012
    Controlling the L6470 microstepper chip from a Parallax Propeller running PropForth. The L6470 is driving a NEMA34 stepper motor in series bipolar mode with 128 microsteps per step. The motor is a 1.8' motor so there are 200 full steps per revolution. I was able to run this motor up to to 2500 RPM but I have limited it now to 2000 RPM = 33.33 rps = 853,333 microsteps/second. You can touch the chip and it is hardly warm. I use 2oz copper and thermal vias so it is simply relying on the pcb, there is no need for further heatsinking.

    BTW, I did get it running faster then that, but this is an early video. A few months after this I created Tachyon Forth as PropForth was too slow, so the project page is actually a Tachyon Forth source code document, I just copy the whole page and paste it into a serial terminal talking to the Prop and it compiles it onchip.
    There is also the L6480 which requires external MOSFETs but can handle much heavier loads but works in the same way.

    EDIT: Can I add that the L298 is very ancient, very ancient indeed and there are much better chips that need far less external components and heatsinks etc. But I guess all the old L298 articles and cheap Ebay prices make the L298 a beginners choice.
  • DRMorrisonDRMorrison Posts: 81
    edited 2014-07-23 20:56
    Peter,
    I saw it spinning at 2500 RPM. That was pretty cool.
    I'm using the L392D now simply because it is on the PPDB. I would like to use something a little better suited to the current draw of my motor. It is a
    200 step bipolar with 4 wires. I'm thinking that the IC you mentioned is a little over kill for what I want to do. I'm using this to move a drill motor up/down
    on a vertical rail. I've had this thing sitting around for years, and would like to use it, but will get something else if necessary.

    Daniel
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2014-07-23 21:01
    DRMorrison wrote: »
    Peter,
    I saw it spinning at 2500 RPM. That was pretty cool.
    I'm using the L392D now simply because it is on the PPDB. I would like to use something a little better suited to the current draw of my motor. It is a
    200 step bipolar with 4 wires. I'm thinking that the IC you mentioned is a little over kill for what I want to do. I'm using this to move a drill motor up/down
    on a vertical rail. I've had this thing sitting around for years, and would like to use it, but will get something else if necessary.

    Daniel

    Sure, if it works and you already have it then certainly, you know the "drill" ;)
    But if you are looking for a cool way to run steppers then this chip is certainly on the short list but I wouldn't consider it overkill when compared to a L293, it just makes better sense.
  • DRMorrisonDRMorrison Posts: 81
    edited 2014-07-23 21:52
    I've looked into it a little more, and I can imagine where this would come in handy. I'm thinking 3-axis CNC.
    Thank you for all of the information.

    Daniel
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