4040 12-bits Counters

Discussion in 'General Electronics Chat' started by Olakunle, Mar 13, 2011.

  1. Olakunle

    Thread Starter New Member

    Mar 12, 2011
    3
    0
    Dear sir,
    I want to read a frequency counter values with visual basic.
    I need 1s i.e 1hz from a 4mhz crystal and I have 2 4040 12-bit counters.
    I can divide each counter by 4096. The problem is that I need to divide one
    4040 by 4000 and the other by 1000 to get 1s.How should I divide by 4000 and 1000
    using AND Gates etc with the Counters?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Have you got data sheets? CD4020, 4040, and 4060 can all give shorter than maximum counts.
     
  3. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    But they can't divide by any number that is not a power of 2. You can use a 4.096MHz crystal, or a 1.024MHz crystal, or 32768Hz crystal, or... any crystal whose frequency is a power of 2.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    1000 = 1024 - 24. 24 = 16 + 8.

    4000 = 4096 - 96. 96 = 64 + 32.
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    I forgot about decoding and short-cycling the counter.:(
    You can divide by 4000 with a CD4020, an 8-input AND gate (CD4068), and a couple of inverters from a CD4049.
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    Ah, but can the OP see the way to decode with the least logic?
     
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