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Controlling a simple DC brushed motor by PWM

Discussion in 'Sensors and Actuators' started by remo_om, Mar 22, 2017.

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  1. remo_om

    remo_om

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    Mar 22, 2017
    Hi guys,
    I want to control a simple brushed DC motor (2 wires). I'm using a PLC with PWM output. I'm looking for a cheap and reliable solution to it. What element would be best for implementing the output to the motor?
    the motor is 24v, 300w.
    Thanks...
     
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    You might be able to find a controller for an old ebike or escooter. 24V 300W brushed motors we're not uncommon prior to the use of brushless DC motors.
     
  3. Minder

    Minder

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    Apr 24, 2015
    What make of PLC?
    If you already have a PWM signal output then feed it into a suitable power Mosfet, add suitable supply for the motor.
    M.
     
  4. Alec_t

    Alec_t

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    Jul 7, 2015
    Do you need to reverse the motor or just control its speed? If reversal is required then things get more complicated.
     
  5. Minder

    Minder

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    Apr 24, 2015
    One possible solution if reversal is needed, as you are using a PLC, total logic control can be achieved with a couple of spare outputs to control a common dual reversing contactor.
    M.
     
  6. remo_om

    remo_om

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    Mar 22, 2017
    I like the Mosfet idea, but I don't know too much about it. Except of high frequency and the wattage, is there any other specifications that I need to take care about? Is zero crossing relevant in this case?
    I do need also reversing the motor but this is not a problem (another 2 relays).
    Thanks...
     
  7. Minder

    Minder

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  8. remo_om

    remo_om

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    Mar 22, 2017
    Thank for the replies.
    Outputs specifications attached. S7-1214 Output.png
     
  9. Minder

    Minder

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    Apr 24, 2015
    If the 100Khz is the freq of the PWM that is fairly high, But I suspect you should be able to do it with a suitable Mosfet.
    If you Google PWM with Mosfet you should get many links to give you the general idea.
    M.
     
  10. Alec_t

    Alec_t

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    Jul 7, 2015
    Don't forget to allow the motor to come to a halt before reversing it, or something could get damaged.
     
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