mod 6 counter 0 IC 74161

Discussion in 'Homework Help' started by daniel000, Apr 28, 2011.

  1. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    Hi guys

    I have noticed on this site there are a few wiring diagrams. I'm just wondering if anyone would be able to assist me on wiring up the following.

    I have to wire up a mod 6 counter using 4 bit binary.

    The image i am following says to use a IC 74161 and it also uses a NAND gate which will need a 74LS00 chip. i have a dip switch for the inputs and resistors. Im just wondering if there is a similar situation that i could follow to assist me in wiring this up on my breadboard

    cheers
    daniel
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. Georacer

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    Nov 25, 2009
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    Do you know what you must do with your parts? The idea is to wire the circuit so that the counter will reset asynchronously when it reaches the count of 7, restarting the count from 0.
     
  4. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    Reset on a count of 7 or reset on a count of 6? The latter gives you six cycles - 0,1,2,3,4,5 - for a modulus 6 operation.
     
  5. Georacer

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    Nov 25, 2009
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    Oh, yes, I forgot we counted 0 too. 6 it is.
    Sorry for the misinformation.
     
  6. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    Thanks for the reply guys.
    And yes I need 6 cycles. With the parts, I have a dip switch which will act as 4 inputs and I will obviously have a count as one , clock pulse and there was also another but I can't remember ATM, there is also four outputs which will be the LEDs. Now I'm Also confused as to how to wire the dipswitch. With the switch do resistors go from the switches to ground and also to Vcc ? And then off too the inputs on to the chip? I'm also confused as to how to wire the NAND chip to the other?
     
  7. Georacer

    Moderator

    Nov 25, 2009
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    What do you need the inputs for? The counter typically doesn't use any input, except maybe for a reset button, which you haven't mentioned.
     
  8. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    So guys,

    There are the four outputs D C B and A. The diagram then has a NAND gate with the inputs attached to outputs C and A which the output of the NAND goes to LOAD which then connects back to the counter.

    There are also 3 other parts connected, Count which is equal to 1, Clear whihch is equal to 1 and Clock pulse.

    I then have inputs , which on this diagram are equal to - and there are four of these.

    im just confused as to how certain things need to be wired
     
  9. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    Here is the sheet im working off to try and give you guys an idea.
     
    Last edited: Apr 29, 2012
  10. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    and this is what i have wired so far..
     
    Last edited: Apr 29, 2012
  11. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    hey guys just a quick update. with the image above, i know im missing a resistor on the last LED.
     
  12. Georacer

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    Nov 25, 2009
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    You have at your hands a counter with a parallel load function. It an extra function that shouldn't bother you for now. All you need is the clock input, and the Count and Clear inputs tied to HIGH. You can ignore the 4 input pins completely if you want. A good practice is to tie them to Ground, though.

    As for the Load input, remember that you want to reset at 6, not 5. You have wired the AND gate to trigger at 5.
     
  13. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    Thanks for that

    So with the two diagrams that I have, especially the second one with the NAND gate, does my wiring look to be OK? Mainly with pin placement and the dip switches and how i have wired that? (i think the function table is wrong for this design)

    Also, you mentioned the four input pins are irrelevant, are these four the inputs that are connected to the switch? if so, these should still connected as no input is regarded as one isnt it? and these need to be zero?

    as for the clock input, and the Count and Clear inputs that need to be tied to HIGH ( connected to Vcc ? ) So far I have, count connected to high dont I? I have pins 7 to 10 connected then 10 to High, is that OK? And for Clear and CP, do i just run wires from pins 1 and 2 to Vcc?

    Also you mentioned i have a AND gate wired up, i thought i needed a NAND lol was this just a typo? and im confused on how to wire it to trigger at 6 where i have it triggered at 5

    thank you for your help, i think im almost done just confused on these last points.

    cheers
    daniel
     
  14. Georacer

    Moderator

    Nov 25, 2009
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    As you correctly pointed, I meant NAND, not AND. In order to make it trigger to 6 you must connect its inputs to C and B, not C and A, because the binary representation of 6 is 0110.

    Personally I don't feel I can help you with the wiring on your breadboard. That can be only done in person. The things that can go wrong are just too many.
     
  15. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    Ok thank you

    So even though the diagram has the NAND gate connected to C and A, i should not have this wired up like that?

    Hopefully someone can have a look at the diagrams on page one and see if that wiring matches the ones on paper

    Also, does the dip switch look like it is wired up correctly?
     
  16. Georacer

    Moderator

    Nov 25, 2009
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    As I said: The diagram shows a NAND gate wired to Load the counter when it reaches 5. You want it to Load when it reaches 6.
     
  17. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    alright sweet, il just leave it the way it is

    anyone else able to shed some light on the other parts that are wired up?


    like the dip switch and other parts of the breadboard?

    thanks
    daniel
     
  18. Wendy

    Moderator

    Mar 24, 2008
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    I see no filter caps. For static digital they aren't as important, if this circuit had an internal clock they would be more important.

    I will disagree with beenthere on one point, neatness is very important. You've done a good job there. It helps spot mistakes (making them easier to see), keeps wires short so they don't act like antennas, and in general improve your chances of having the circuit work the first time you power it up.

    http://forum.allaboutcircuits.com/showthread.php?t=53866

    The vast majority of projects I was careful to lay out well worked the first time, unlike some of the rats nests from my early days.
     
  19. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    Thanks mate

    We dont require any filter caps for this, but thanks anyway.

    As for my wiring does this look ok compared to the written diagrams? How does my dip switch look, is that wired up ok?

    cheers guys
     
  20. daniel000

    Thread Starter New Member

    Apr 3, 2011
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    and by wiring i mean pin placement and if the dip switch is correctly wired up ?
     
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