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wondering about what motor controller — Parallax Forums

wondering about what motor controller

whiteoxewhiteoxe Posts: 794
edited 2014-06-05 16:59 in General Discussion
I mistakenly bought a stepper motor controller board for $4.00. Ive only ever driven a servo motor before so i just need a little clarification. When I searched for a motor controller , its to run the motors identical to that in the Scribbler i get a lot of different results. One is an IC SN754410 Quad Half H-Bridge Motor Driver 1A (L293D compatible) price $2.95 ;)

can that do the job of one of the boards which look quite different with all those extra parts ? The schematic makes it look easy to connect and claims to run from 6 to 15 volts ?

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-06-05 08:19
    I don't think I'm the only one who wishes you'd ask related questions in the same thread.

    By starting a new thread, others aren't aware of the previous advice given. If you do start a new thread, IMO, it's considerate to add a link to the previous discussions as well as links to the parts you're asking about.

    Which motor controller did you buy for $4? Many motor controllers are "half h-bridge" circuits which can be used to drive stepper motors or normal brushed motors (they can also be used to power LEDs (I use some SN754410 chips to power the anodes of my RGB arrays)). Your stepper motor controller board may work fine with a normal DC motor.

    Many of the "extra parts" on some PCBs are flyback diodes to protect the electronics from voltage spikes. Some chips have internal flyback diodes but there's debate whether or not these chips should also have external flyback diodes. If you read the discussion in the comments under the SN754410 chip at SparkFun you'll see some of this debate.

    The SN754410 is mentioned several times in the other thread. Besides using SN754410 chips to drive small brushed DC motors, I've used them to drive stepper motors.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-06-05 09:30
    Well thx for the scolding and linking back to where i'd already asked.I deserved it,,,, ive been going in so many directions but that seems a poor excuse. I will now go and read every post and thread ive made in the last couple of weeks..
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-06-05 12:36
    http://www.pololu.com/product/2130

    I dislike the LM293 and LM298 devices as they have BJT h-bridges which are large and waste a lot of power. The above is a nice little Mosfet h-bridge that is smaller, runs cooler, and wastes less battery power.

    Or maybe this... more powerful
    http://www.parallax.com/product/28820
  • whiteoxewhiteoxe Posts: 794
    edited 2014-06-05 15:03
    yep loopy but Im sticking with a beer budget though the first one is doable. But you canget motor drivers from ebay for $4.00 and there is no postage fee. I dont know how they do that. Posting a letter in Australia costs 70 cent ?

    I might try this http://www.ebay.com/sch/i.html?_odkw=LM393+motor+driver&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR3.TRC1.A0.H0&_nkw=SN754410+&_sacat=0 Thx Duane

    actually, the stepper motor driver ive bought is the same as the one you have a link to back in the other thread. So I might be fine, i have to go to the post office to collect, two of them.
  • GenetixGenetix Posts: 1,754
    edited 2014-06-05 16:59
    It might waste power but the L293D is easy to use and has internal kickback diodes.

    http://www.parallax.com/downloads/stampworks-experiment-kit-manual
    Look at Experiment #27 on page 150 (page 160 of the PDF)
    Here's the code for it
    http://www.parallax.com/downloads/stampworks-basic-stamp-source-code
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