Speed encoder for speed feedback

Discussion in 'The Projects Forum' started by Chaabane, Dec 24, 2009.

  1. Chaabane

    Thread Starter Member

    Nov 30, 2009
    37
    0
    Hello,
    here is my problem
    i need to detect the speed of a DC motor.
    so i should use an increment speed encoder.
    for this I need a timer to count the pulses,and calculate the speed.
    unfortunately,i'm out of timers in my application
    is there an external circuit to add with the encoder so you i can get an analog speed value.???
    or i don't have to use a timer in the first place ????
    Help please
     
  2. eng1ne

    Member

    Dec 4, 2009
    97
    3
    Is it one particular dc motor? If you able to choose a motor with a dedicated feedback signal, get one.

    Otherwise, if you can't change the motor, what is the application for the motor? What will the analog signal you generate ultimately be used for?
     
  3. steveb

    Senior Member

    Jul 3, 2008
    2,433
    469
    Yes, there is.
     
  4. Chaabane

    Thread Starter Member

    Nov 30, 2009
    37
    0
    here my project that i'm working with

    http://forum.allaboutcircuits.com/showthread.php?t=30865

    so i can read it with my pic,rather than reading pulses directly.

    #steveb
    can you tell me more about this circuit,i guess its an external digital/analog converter!
     
  5. Chaabane

    Thread Starter Member

    Nov 30, 2009
    37
    0
    Well ,i thought of this ,but its not practical,the dc generator need space,which i don't have...thanks
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
    397
    For DC motors,24V, 125 to 450W, try All Electronics. For an analog V speed signal: use reflective sensor with alternating white/black segments on disc or drum [shaft ], differentiate output to obtain uniform pulse, integrate with a current bleed, to give V porportionate to speed.
     
  7. Chaabane

    Thread Starter Member

    Nov 30, 2009
    37
    0
    ok, i didn't really understand,but i'll try it.thanks
     
  8. Chaabane

    Thread Starter Member

    Nov 30, 2009
    37
    0
Loading...