SR Latch Initialization ?

Discussion in 'General Electronics Chat' started by parkhid, Dec 20, 2010.

  1. parkhid

    Thread Starter New Member

    Dec 20, 2010
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    In the name of God
    -------------------------
    Hi , as far as we know , this is SR latch figure.

    [​IMG]
    I am wondering how this circuit will work ?

    We have not the value of Q to NOR it by S .
    We have not the value of !Q to NOR it by R .

    How people have drawn a truth table for it ???

    Please Help me to understand..

    Thanks in advance
     
  2. beenthere

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    Apr 20, 2004
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  3. Jony130

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  4. parkhid

    Thread Starter New Member

    Dec 20, 2010
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    Sorry . I have not understand

    I will assume that we don't know the value of Q.
     
  5. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    But if you put H state to the input R, then you will have L state in Q becaues it's NOR gate.
    So know you now the value of Q.
     
  6. parkhid

    Thread Starter New Member

    Dec 20, 2010
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    But
    According to the first Nor gate ,it needs !Q also to NOR it with R signal.
    Where is The !Q value ?
    -------------

    Thanks in advance
     
  7. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    You do not need to know !Q if you put H to R terminal.

    NOR truth table

    A B Q
    0 0 1
    0 1 0
    1 0 0
    1 1 0

    If one or both input is HIGH (1), a LOW output (0) results
     
  8. parkhid

    Thread Starter New Member

    Dec 20, 2010
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    Thanks Jony :

    Solved ....
    Really Thanks .

    I have got confused.

    Thanks in advance.
     
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