pulse delay

Discussion in 'The Projects Forum' started by Jumper68, Feb 10, 2011.

  1. Jumper68

    Thread Starter New Member

    Feb 8, 2011
    4
    0
    Hi

    I have made a circuit with 3 4017 IC´s, so i can count to 1000, and then it starts over. The problem is at the last output of the last 4017 stays on to long, i only ned a short puls output like 0,25 to 0,5 seconds.

    Short explantion.

    long puls in -> only 1 short puls out, until next long puls

    Any one who can help?
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    Can you post a schematic of the circuit?
    The preference for the fileformat for it is .png or .pdf.

    Bertus
     
  3. Jumper68

    Thread Starter New Member

    Feb 8, 2011
    4
    0
    In have now uploadede on in pdf format
     
    • jm.pdf
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  4. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    You will get 1000 times longer pulses on the output of the third 4017 as the input clock pulses.
    You say that you want 0.25 to 1 second pulses every 3 minutes (that is 180 seconds).
    You can take a AND port , connect the 9 of the third, the 9 of the second and the carry of the first to the inputs of this port and you will have 0.9 seconds every 180 seconds, when the clock time is 0.18 seconds.

    Bertus
     
  5. Jumper68

    Thread Starter New Member

    Feb 8, 2011
    4
    0
    No you can´t say that the output is high in every 3 min.

    I have made this as a counter, it´s count to 1000 (after 1000 inputs). When it reach 1000 counts, output 9 on ic3 (1000) goes high. But it may only stay high for 0,25 to 1 sek regardles of what state output 9 stays in.
     
  6. CDRIVE

    Senior Member

    Jul 1, 2008
    2,223
    99
    You can do something like this or you can use a 555. If you use a 555 you'll still need an NPN to invert the your signal to the Trigger input.
     
  7. Jumper68

    Thread Starter New Member

    Feb 8, 2011
    4
    0
    I will try that, in advance thanks for your help.:)
     
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