johnson counter

Discussion in 'Homework Help' started by bian momani, Feb 22, 2010.

  1. bian momani

    Thread Starter New Member

    Feb 22, 2010
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    hi
    how to Design Johnson counter using 74ls191,74ls194,JK flip flop,and other component if needed.????????????????????????????????
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. bian momani

    Thread Starter New Member

    Feb 22, 2010
    6
    0
    hi
    this link not help me ...........thanx any way
     
  4. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,644
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    Get the datasheet of CD4017, proabbly the most popular ever amongs hobbyists.
     
  5. Papabravo

    Expert

    Feb 24, 2006
    10,135
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    I don't understand. Was there something wrong with the link?
    You start with a shift register, and an inverter. Take the output of the most significant stage and route it back to the shift register input through the inverter. Reset the shift register to all ones or all zeros. Now each time you clock the shift register you will see either ones or zeros walking through the shift register.
     
  6. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Of course, there's also that little circuit (the NOR gates in the 4017) that gets it into the correct sequence if it should find itself in one of the "short cycle" states. All Johnson counters with 3 or more stages need that function.
     
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