how can i preset the 74192??

Discussion in 'Homework Help' started by pr1111, Jul 10, 2010.

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  1. pr1111

    Thread Starter Member

    Jul 8, 2010
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    i want it to count like this 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 1 2 and so on

    @mod
    sorry for making many new threads
    i just want others to easily know my problems
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
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    Oh, you've got some problems..We have NO problem seeing that ;)

    Ok, do you have the data sheet? If not, it is attached. Read it.
    http://focus.ti.com/lit/ds/symlink/sn74190.pdf

    Aight, you need to set the IC to count UP and give it a clock. That will count make it count.

    You have a VERY odd counting scheme so you will need to use logic to do your multiple resets.
     
  3. pr1111

    Thread Starter Member

    Jul 8, 2010
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    i am going to use this on a 12-hour clock

    i already made a 24-hour circuit and it's working

    i want to make it a 12-hour clock

    i used a 74ls192 and it is counting 0-9

    i want it to count like in the 12-hour clock 01 02 03 04 05 06 07 08 09 10 11 12 01
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
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    To PRESET the 74191, you need to put the pins HIGH that equates to the number you want to start at, then you send a LOW to the LOAD pin.

    The counter will start from the number you just programmed in.

    This is on the FIRST page of the datasheet. Reading it will tell you what you want to know.

    If you replace your 192 with a 191, you are 90% there. It will work the same way, they have different MAX numbers.
     
  5. pr1111

    Thread Starter Member

    Jul 8, 2010
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    [​IMG]

    what should i do with this??

    it counts from 0-9

    i want it to count from 1-9 0 1 2 1-9 0 1 2 1-9 and so on

    just like in the clock 01 02 03 04 05 06 07 08 09 10 11 12 01 02
     
  6. Wendy

    Moderator

    Mar 24, 2008
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    This is a major mistake. By doing this you create a highly confusing hodgepodge of different threads, which one are we supposed to use? when addressed with this my inclination is to use none of them. You are much better sticking with one thread, and addressing your problems one by one sequentally.
     
  7. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    This is the third thread pertaining to this one clock project.

    You only need one.
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    One side issue. ALWAYS tie your unused inputs to either high or low. TTL will assume high (which may not be what you need), but some logic families get very hinky when presented with this problem.

    It take me a while to look into 74192, some drawing required.
     
  9. beenthere

    Retired Moderator

    Apr 20, 2004
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