Soft start motor control

Discussion in 'The Projects Forum' started by bignos, Feb 11, 2011.

  1. bignos

    Thread Starter New Member

    Feb 11, 2011
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    Hi,
    I need to make a soft start circuit to control a motor with up to 16v dc drawing approx 1 - 1.3 amps.

    The input voltage may vary between 1-16v and the idea is for there to be a safety delay between the rise or fall in voltage and output, this delay should ideally be adjustable...

    Where do i start?
     
  2. Adjuster

    Well-Known Member

    Dec 26, 2010
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    What do you mean? A voltage rises (or falls), and the output changes after a delay? How does this make anything safer?

    A soft start is usually a slow progressive one - is this what you want? Try to describe what you need in more detail.
     
  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,675
    899
    @bignos: There are various ways to have soft start. Individual motor control chips are available that are basically PWM controls that ramp the start. Similarly, one can do the same with a microcontroller. How much effort do you want to put into the project? Do you want to buy a ready made controller?

    This link has a lot of related information. While there is a lot there, it will give you some of the flavor for what you are wanting to do.

    http://www.educypedia.be/electronics/circuitsmotorcontrol.htm

    John
     
    Last edited: Feb 12, 2011
  4. bignos

    Thread Starter New Member

    Feb 11, 2011
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    the input voltage is infinitely variable between 1-16v, i want this same voltage to pass through a circuit and come out the other side delayed from the input.
    This delay must be able to be increased or decreased as needed for setup

    The delay adjustment just delays the voltage getting to the max voltage inputted

    does this make it any clearer?
     
  5. Adjuster

    Well-Known Member

    Dec 26, 2010
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    Not really. I suppose this may be a problem of translation into English:

    I would understand DELAYING the voltage change to mean making it happen some time after the input change, but not necessarily more slowly.

    On the other hand, to achieve a soft-start, the rise to maximum voltage must happen MORE SLOWLY. As a result, there would of course be some delay in reaching the final value.

    Which do you want - the voltage to change later but at the same speed, or to change more slowly, with delay as a side-effect?
     
  6. bignos

    Thread Starter New Member

    Feb 11, 2011
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    to change more slowly
    ie if a full 16v is instantly applied on the input, the voltage on the output will slowly increase to the 16v
     
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