1 to 12 digital counter

Discussion in 'The Projects Forum' started by ragnorkano, Aug 19, 2006.

  1. ragnorkano

    Thread Starter New Member

    Aug 19, 2006
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    When I was younger, I designed a counter circuit to count form 1 to 8 and restart back at 1. Now I am trying to modify the circuit to count to 12.
    I have enclosed the circuit for the 8 counter, and the binary count sequence.

    I think that if I cnange the pin connect on pin 3 on IC 8A from high to pin 2, that would take the count to 12, but it would need to reset to 1 on the next clock pulse instead of continuing to count up.
    Also, the display would need to be modified to show 10, 11, & 12 on two 7 seg dis. instead of the usual blank or 0, A, B on one display.
    The IC's currently in use are 74LS107 JK Flip Flops, 74LS08 duel AND gates.
    The CD4066 is used for isolation from other inputs going to the BCD to 7SEG decoder.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    If you grab a binary counter, you can arange for it to short count at 12 (B) instead of going to 15 (F). A couple of external gates will do the trick.
     
  3. ragnorkano

    Thread Starter New Member

    Aug 19, 2006
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    Okay, so I use a 'CD40163B' counter and reset it at the next clock pulse on the count of 12 (B).
    Any sugestions on how to show 01 - 09, 10, 11, 12 on two 7Seg displays.
    01 through 10 isn't so hard, but I'm getting stumped on 11 and 12.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    you will have to use two decade counters, or else a lot of external logic for the second display. Look at '160s instead of the '163.
     
  5. ragnorkano

    Thread Starter New Member

    Aug 19, 2006
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    wont it be easier, with less external logic, to use the 163 due to it be synchronous?
    The less external logic gates needed would be better due to board space and trace design.
     
  6. Chris Wright

    Well-Known Member

    Jul 26, 2006
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    Your file says "digital Dice". If this is what your are simulating, wouldn't the correct analogy be a count of 1-6 in each display to represent each one of the dice?
     
  7. Søren

    Senior Member

    Sep 2, 2006
    472
    28
    Hi,

    If he's willing to "fake it", it only takes one bit to switch between zero and one - connect segment B and C permanently and couple the rest (less segment G of course) together and switch those on when it's a zero and off when it's a one.
     
  8. ragnorkano

    Thread Starter New Member

    Aug 19, 2006
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    Chris, the digital dice is for a set of dice with different number of sides.. 4, 6, 8, 10, 12, 20, & 100.

    Soeren, wouldn't that make the diplays show 03-12 okay, but show 11 and 12 for 01-02, giving a count of 11, 12, 03-10, 11, 12?

    If anywone can help out on this with a diagram, it woulld be greatly appreciated to no end.
     
  9. ragnorkano

    Thread Starter New Member

    Aug 19, 2006
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    0
    :rolleyes: thanks for everyones help.
     
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