How to we do Boolean expreesion.

Discussion in 'Homework Help' started by Ricky Sum, May 7, 2016.

  1. Ricky Sum

    Thread Starter New Member

    May 6, 2016
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    Can anyone explain how we do boolean expression. And how to do it.
     
  2. dl324

    Distinguished Member

    Mar 30, 2015
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    Is this homework?
     
  3. crutschow

    Expert

    Mar 14, 2008
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    Difficult to explain in a few sentences.
    Here are some references.
     
  4. dl324

    Distinguished Member

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  5. WBahn

    Moderator

    Mar 31, 2012
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    MOD NOTE: Moved to Homework Help from General Electronics Chat.
     
  6. WBahn

    Moderator

    Mar 31, 2012
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    One of the first steps should be to get the original circuit into nothing but one- and two-input gates. Can you change the 3-input AND gate into a subcircuit that uses only 2-input gates (doesn't matter what type).

    Next is to translate the different one- and two-input gates into equivalent subcircuits that only use 2-input NAND gates. You can do those off to the side one at a time. At the most basic Boolean expression level, you only have three gates to worry about - NOT, OR, and AND. Can you make each of those out of just 2-input NAND gates? If not, that is the first thing you need to focus on.
     
  7. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I have taken your picture, cut out the essential part, adjusted brightness and contrast.

    Ricky_sum_boolean.jpg

    Please cut away any unwanted parts next time.

    Bertus
     
  8. WBahn

    Moderator

    Mar 31, 2012
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    Check your expression for Z that you have drawn on the diagram. Hint: The middle gate is not and OR gate.
     
  9. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    Reading textbook helps.
     
  10. thumb2

    Member

    Oct 4, 2015
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    I am not sure if you're expression for the NOR output is right.

    You have a NOR with both its input inverted.
    So it should be (\overline{\bar A + \bar B}).
    Making a thruh table for the 2NOT -> NOR Gate I get:

    \begin{array}{c c | c }<br />
A & B & \overline Y\\<br />
0 & 0 & 0\\<br />
0 & 1 & 0\\<br />
1 & 0 & 0\\<br />
1 & 1 & 1<br />
\end{array}<br />

    where A and B are the non inverted inputs. So The final output can be reduced to

    Y = (A \wedge B \wedge B)

    For a & b ceck out NAND logic and NOR logic.
     
    Last edited: May 8, 2016
  11. dl324

    Distinguished Member

    Mar 30, 2015
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    There is no Y in the original problem. If you meant Z, you dropped C.

    This is the Homework Help forum and members are expected to provide guidance to the OP so they can learn how to do it themselves.
     
    Last edited: May 8, 2016
  12. thumb2

    Member

    Oct 4, 2015
    66
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    Yes I ment Z and I forgot C ...
    Uh OK ...
    Regards
     
    Last edited: May 8, 2016
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