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uln2003 data sheet question.

Discussion in 'General Electronics Discussion' started by Dude22, Sep 15, 2012.

  1. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    As long as the power supply is capable of operating all the motors simultaneously under full load, you don't have a problem. If that requires 15A, and your power supply is capable of 20A, 200A, or even 2000A, then you simply don't worry about it.

    The only concern is when the power supply in insufficient to operate all the motors. In that case you need to ensure that only *some* of the motors are used simultaneously, or that they are not operated at full capacity or load simultaneously.
     
  2. CocaCola

    CocaCola

    3,635
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    Apr 7, 2012
    I wouldn't bother, the axis drivers can be had for less than what I can build them for from China... Some designs are better than others, look for one with heat sinks mount it in a box with plenty of airflow... I used a common US mailbox and 6" computer fans, for my setup with a 'blow in' fan on the front and and a 'pull out' fan on the back giving a lot of airflow down a tunnel... The open frame power supply and axis controller are both mounted in there on stand offs to give airflow on all sides, heat sink fins are aligned with airflow, I cock the fins at a slight angle to catch a little more air, as I feel it might help... But, with the two fans pushing and pulling the things stays pretty darn cool, but is noisy...

    I use cheap open frame ones, they are not known for their longevity but I have a backup on hand since they are so cheap...

    One thing to note about mine and Steve's comments on total power, with CNC the motors are pulsed, they are never really 'on' so you can sorta underrate the power supply in most cases... I said plan for worst case on the driver board, but you really might want to measure your motors when choosing a power supply as it can be cost prohibitive to get a supply high Amp one if not needed...
     
  3. Dude22

    Dude22

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    Mar 30, 2012
    but what about the MOSFET's, they are quite cheap and from what was said here, should work. My question is how would I wire the MOSFET's and how many would I need with what rating, then I can find out what sytem is better/ cheaper.
     
  4. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    MOSFETs are only one component of the axis controller, it takes more to build the entire interface to the computer...

    Pick a MOSFET and read the datasheet, it's not always fun but someone has to do the leg work... The searches on websites like Digikey allow you to limit your searches based on specific specifications... Once you have the MOSFET picked out you can read the datasheet for how to hook that particular one, as has been said above it's nearly the same way you would hook up the ULN chip...
     
  5. Dude22

    Dude22

    66
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    Mar 30, 2012
  6. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    I already said I would just purchase one, as it's simply not cost effective to make one unless you require or desire features not found in an over the counter one... If you discover your motors are 3.5A or less that controller might be an option... Just be aware as I have suggested, the Chinese like pushing designs to the limits, I can't emphasis how important it is to keep the air flowing and keep them cool, or else they will fail...
     
  7. Dude22

    Dude22

    66
    1
    Mar 30, 2012
  8. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
  9. Dude22

    Dude22

    66
    1
    Mar 30, 2012
    I have found some info on my motors, they require 1.3amps. I have found a few drivers that I think will work, but I am not sure what will work best with my motors and will also last (IE: not cheap Chinese). Below is a list of the 4 drivers I have narowed it down to. I would also need the driver to work with linix CNC and Mach3.

    1: http://www.ebay.ca/itm/4-axis-TB656...296?pt=LH_DefaultDomain_0&hash=item45fca29ab8

    2: http://www.ebay.ca/itm/CNC-TB6560-4...712?pt=LH_DefaultDomain_0&hash=item2a1cae9068

    3: http://www.ebay.ca/itm/Aluminum-Box...690?pt=LH_DefaultDomain_0&hash=item4d04fed66a

    4: http://www.ebay.ca/itm/New-4-Axis-T...203?pt=LH_DefaultDomain_0&hash=item41661be843

    Any advice you all can give me would be GREAT:):):)
     
  10. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    Those are ALL cheap 'Chinese' boards, that is what proliferates the DIY CNC hobby... In fact they are all the same or near identical cheap to make flawed design, just produced by different 'Chinese' companies... I'm not saying they won't work, sometimes, but none of them are high quality, they will all run quite hot, you will need to counter that heat if you want them to last and even then they won't run perfect... Run the machine slower and/or keep a lot of air flowing across them and you can get OK but not great results...

    Just for giggles Google 'tb6560' 'tb6560 flawed' 'tb6560 smoked' or something like that, enjoy reading...

    Just like the cheap power supply pick up a spare one so you have it on hand when the one you are using lets out the magic smoke...
     
  11. Dude22

    Dude22

    66
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    Mar 30, 2012
    would they all work with mach 3 and linux cnc???
     
  12. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    They 'should' all work with software that supports a parallel interface... Contact the seller if you want confirmation...
     
  13. Dude22

    Dude22

    66
    1
    Mar 30, 2012
    Ok I think I have narowed it down to 1 driver: http://www.ebay.ca/itm/4-axis-TB656...296?pt=LH_DefaultDomain_0&hash=item45fca29ab8

    I have a question reguarding the power suply, I now know the motors draw 1.6amps for a total of 4.8amps (the reason I am looking at a 4 axis driver Is because I want to eventually have a 4th motor) This brings the total amprage need up to aprox 6.4 amps (if I use the same motor) So a 10 amp power supply should be safe. But what about wattage??? what is enough/not enough for 4 motors???
     
  14. CocaCola

    CocaCola

    3,635
    4
    Apr 7, 2012
    Amps * Volts = Watts

    6.4 * Volts = Watts
     
  15. Dude22

    Dude22

    66
    1
    Mar 30, 2012
    Hi everyone, its been a while and I finally got my driver. I am having some trouble wiring my 6 wire motors to the 4 plugins... I have tried lots of different wiring configurations and all i get is the motors locking when I trigger E-stop (this happens no matter how I wire it). I have confirmed the signal is getting from the computer to the board as when I try to jog the motors the "active" light, lights up on the board. Does anyone have any suggestions as to what I might try???

    Thanks
     
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