Pages: 26 (7061 words) Published: November 3, 2012

1. Sensors are used to monitor the pressure and temperature of a chemical solution stored in a vat. The circuitry for each sensor produces a HIGH solution when a specified maximum value is exceeded. An alarm requiring a LOW voltage input must be activated when either the pressure or the temperature (or both) is excessive. Draw a truth table with the desired inputs and outputs and from that design a circuit for this application.

Two inputs → P T
P - Pressure
T - Temperature

If either the pressure or the temperature or both parameters increases the specified value, a high voltage must be produced. Those high voltages must be converted to low voltages and supplied to the alarm to make rings.

|P |T |Output (A) | |0 |0 |0 | |0 |1 |1 | |1 |0 |1 | |1 |1 |1 |

_
→ F= PT
_
→ F= PT

→ F= PT

_ _
F= PT+ PT+ PT
_ _
F= PT+ PT+PT
_ _
F= P (T+T) + PT
_
F= P + PT

P T

_
F= P + PT

2. Digital circuit has three inputs A, B and C and three outputs X, Y and Z.The truth table is given below. Determine separate Boolean expressions for X, Y and Z and draw the logical diagram.

|C |B |A | X | Y | Z | |0 |0 |0 |1 |0 |0 | |0 |0 |1 |0 |1 |0 | |0 |1 |0 |0 |1 |0 | |0 |1 |1 |0 |0 |1 | |1 |0 |0 |0 |1 |0 | |1 |0 |1 |0 |1 |0 | |1 |1 |0 |1 |0 |0 | |1 |1 |1 |0 |0 |1 |

For “X” Output
_ _ _ _
X = A B C + A B C
_ _ _
X= A (B C + B C)

A B C

_ _ _
X= A (B C + B C)

For “Y” Output
_ _ _ _ _ _ _
Y= A B C + A B C + A B C + A B C
_ _ _ _ _ _
= A B (C+C) + A B C + A B C
_ _ _ _ _
= A B + A B C + A B C

ABC

_ _ _ _ _
Y = A B + A B C + A B C [pic]

For “Z” Output
_
Z = A B C + A B C
_
= A B (C + C)

= A B

A
Z= A B

B

IDM Computer Studies (Pvt) Ltd wants to change its entire manual system to a computerized system to face the changes in Information and Communication technology in the new millennium.

For the above change, you should gather information in the following to carryout the changes in the organization. Describe the followings according to the...