lotus23 : circuit for PWM, open loop drive

Discussion in 'The Projects Forum' started by lotus23, Sep 1, 2010.

  1. lotus23

    Thread Starter New Member

    Aug 31, 2010
    I need a circuit to PWM, open loop drive a 12v dc motor. I want to use a toothed wheel with a hall effect sensor to control the speed of the brushed dc motor. I also need calibration capability within the open loop for speed adjustment. I hope this is a common application, Thus far I have not found a specific circuit for this. Thanks....JCR
    Last edited by a moderator: Sep 1, 2010
  2. SgtWookie


    Jul 17, 2007
    Sure, it's very common, just do a Google search on it. However, with an open loop drive, I don't know how you expect to control the speed.

    Your subject title is not very helpful; don't expect many other replies.
  3. lotus23

    Thread Starter New Member

    Aug 31, 2010
    My apologies...JCR
  4. BillB3857

    AAC Fanatic!

    Feb 28, 2009
    If you are using a toothed wheel with a sensor to measure the RPM and thus control the PWM circuit, you will have a CLOSED VELOCITY LOOP, not an open loop. Basic tachometer feedback.