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D.C motor speed controlImportant

  1. Jun 24, 2010 #1
    Hello everyone

    I have a small question concerning D.C motors speed control. I would like to ask about the "novice method"? I can't seem to find enough information about it, so can anyone just give me a brief explanantion of it? and what is the circuit used for it? otherwise can you give me any other explanation and circuit of any other D.C motor speed control?

    Thanks a lot.

    I really appreciate it.
  2. jcsd
  3. Jun 24, 2010 #2


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    Staff: Mentor

    I believe you would usually use PWM of the DC input voltage to control the speed. Maybe the "novice method" is just reducing the drive voltage? That doesn't work very well, so maybe that's why they call it that?
  4. Jun 24, 2010 #3
    By novice I think he just meant the easy way, in which case just decrease the voltage. If you need accuracy though use PWM.
  5. Jun 25, 2010 #4
    I have never heard of the 'novice method' though like the other posts I feel that it indicates a simplified method of control. With a static input DC voltage, this can be done with a variable series resistance. I have included a PDF document attachment, which explains PWM and H-bridge control of DC motors, though the H-bridge is not the most simple of SCR DC motor control it is the most versatile. Its not great but I hope it is of some use.

    Attached Files:

  6. Jun 25, 2010 #5
    One other point. The higher the frequency of the PWM signal, the more eddy currents will be produced and the hotter the motor will become. In other words, don't use a 40 kHz PWM signal if a 60 Hz PWM signal will suffice.
  7. Jun 26, 2010 #6
    Thanks a lot everyone, I really appreciate it, the information was very helpful..
    I think then I will end up using PWM method for my project..
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