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Homework Help: Industrial current to pneumatic convertor

  1. Aug 23, 2011 #1
    1. The problem statement, all variables and given/known data
    A Current to pneumatic convertor which is shown here in the attachment has the given data which is
    Kc=2500N/A (constant of proportionality
    X+Y = 100mm

    1-to check the response of I/P as per graph waht is the suitable value of x and y
    2- what is the value of Fs

    2. Relevant equations

    Pout = (Kc*Y/A*X)Iin+Fs*Z/A*X

    3. The attempt at a solution
    Given data is
    Kc =2500NA-1 or 2500,000mNA-1

    X+Y = 100mm


    A= 5cm^2 or 500mm^2

    The balance equation of the system is

    Pout = (Kc * Y/A*X)Iin + Fs*Z/A*X


    Now by looking the graph the intercept c of the line run through zero so
    The Fs*z/A*X part of the equation iS neglected so new equation is lik
    Pout = (Kc*Y/A*X) Iin

    Or Y = MX

    As per the graph the value of
    Pout =1 bar or 100,000pascals
    Iin = 20mA
    now by putting these values in the above equation
    100,000 = ( Kc*y/A*X) 20

    Kc*Y/A*X = 5000

    Now by putting the value of Kc and A

    2500,000*Y/500*X = 5000

    Y/X = 1
    Now as per the given data the

    X+Y = 100
    And Y = 100-X

    Now by putting this value of X in the above equation

    100-X/X = 1
    100-X =1X
    100 =1X+X
    100 =2X
    X =50mm

    Now by putting this value of X in the given x+y =100 we will get the value

    X+y = 100

    50+Y = 100

    Y = 100-50

    Y = 50mm

    so the value of x = 50mm and Y= 50mm
    I am not sure this the correct solution and the unit selection is correct or not
    If any friend has some idea about this plz guide me

    Attached Files:

    • doc.doc
      File size:
      81 KB
  2. jcsd
  3. Aug 24, 2011 #2


    User Avatar

    Staff: Mentor

    Your values for x and y look okay to me.
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