Carno table problem

Discussion in 'General Electronics Chat' started by emicho, Dec 7, 2012.

  1. emicho

    Thread Starter New Member

    Apr 9, 2012
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    Hello guys,
    I need to design a digital circuit which have five inputs " A,B,C,D,E"
    and one output..
    the output should be "1" when the input is a prime number
    please I need you to helps me to find the reduced equation of the output
    "using Carno table"...
     
    Last edited: Dec 7, 2012
  2. John P

    AAC Fanatic!

    Oct 14, 2008
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    Of course you checked to see what English-language answers come up when you look online for <carno table>. Knowing what your readers here would be likely to do.

    You did, right?
     
  3. emicho

    Thread Starter New Member

    Apr 9, 2012
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    well yes, but why are you asking??
     
  4. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    I'm lost. Is the OP spamming?
     
  5. emicho

    Thread Starter New Member

    Apr 9, 2012
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    Hey!!!
    I think I miss understand what you have said
    I really have a problem with carno table which is the map method which we use to simplify a boolean function...
    please I need help with my problem
     
  6. John P

    AAC Fanatic!

    Oct 14, 2008
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    Oh, you mean a CARNAUGH table. Why not just say so?

    Now explain what your inputs actually do.
     
  7. Papabravo

    Expert

    Feb 24, 2006
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    You're all wrong. It is spelled with a 'K', not a 'C'

    http://en.wikipedia.org/wiki/Karnaugh_map

    For 5 inputs it will be hard to see the patterns across 2 tables. There are more effective algorithmic methods.
     
  8. John P

    AAC Fanatic!

    Oct 14, 2008
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    Oops. Well, my spelling is close enough to get you to the right place. However, I was able to get there and not notice that I had it wrong. Not too observant, sorry.

    Anyway, how does this relate to prime numbers?
     
  9. tshuck

    Well-Known Member

    Oct 18, 2012
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    Karnaugh maps begin to get difficult to use past 4 variables, but 5 is certainly doable.. Have a look here before you begin...

    Now, once that is out of the way, draw your K-map and put a 1 wherever the output should be a 1, corresponding to your input variables... So, you will eventually come to a Boolean expression for determining prime numbers....
     
  10. emicho

    Thread Starter New Member

    Apr 9, 2012
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    Thanks Guys, I have some PDF about it but the problem: I don't have time to read all this and I need your help to get the reduced equation of the output
    "using Carno table" so that I can draw the digital circuit and I shout finish it today,

    Thanks for all of you friends...
     
  11. Papabravo

    Expert

    Feb 24, 2006
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    Sorry. We were not put here to do your work for you. You absolutely must make an effort. We are here to help, but you need to do the work. Understand?
     
  12. tshuck

    Well-Known Member

    Oct 18, 2012
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    I'm afraid that if you don't have time to understand your problem, you don't have time to come to a solution.....
     
  13. vpoko

    Member

    Jan 5, 2012
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    You can use Mathematica or Wolfram Alpha to reduce boolean functions to a minimal form. Of course, if you have to use Karnaugh maps and show your work, you'll be out of luck.
     
  14. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Sounds like someone's homework is due soon. ;)
     
  15. WBahn

    Moderator

    Mar 31, 2012
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    As pointed out by others, an attitude like this will not get you very far here. But, more important, it will not get you far in your goal of learning anything (if, in fact, that actually is one of your goals) and it will not serve you well as an engineer. So if this is going to be the way you operate, get the hell out of engineering, both for your own sake and the sake of the people you will otherwise almost certainly get killed sooner or later.

    Now, should you be interested in getting your act together, consider the following questions on this problem:

    Q1) How do the lettered inputs, A, B, C, D, and E, map to a number (which is then either prime or not)?

    Q2) How many possible input combinations are there that need to be dealt with?

    Q3) How many combinations need to produce a '1' output?

    Q4) Are any of the inputs always (or nearly always) in a particular state when the output is '1'?

    Q5) Might it be easier to identify the cases for which the output should be '0'?
     
  16. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    While this attitude may makes horrible engineer,it does strongly remind me of at least one engineering manager I've worked for.
     
  17. MrChips

    Moderator

    Oct 2, 2009
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    Isn't that what managers are there for? They manage people but know bugger all about engineering.
     
  18. WBahn

    Moderator

    Mar 31, 2012
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    Yeah, I was strongly tempted to make some recommendations of fields he might want to consider. But I managed, barely, to refrain myself. ;)
     
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