Reference no: EM131676685
1. (a) By using a truth table show that the expressions
are equivalent.
(b) Show by plotting truth tables that
2. (a) Draw the logic circuit to represent the following Boolean expression using only NAND gates.
(b) Draw the logic circuit to represent the following Boolean expression using only NOR gates.
Indicate the outputs of each gate.
3. In the ladder diagram shown in FIGURE 1, Y006 is a lamp, X and R references are relay contacts. Write down the Boolean expression for the lamp to light.
FIG. 1
4. (a) Add the following HEX numbers converting to binary. Express the answer in HEX.
(i) 08 + 03
(ii) 0ABC + DA0E.
(b) Write down the 2's complement of:
(i) 00000001
(ii) 00111100
(c) Convert the following denary numbers to 8 bit binary numbers and evaluate using the '2's' complement' method. Leave your answers in binary form.
(i) 17 - 8
(ii) 97 - 125
(d) (i) Write down the bcd form of decimal 845.
(ii) Convert the denary number 818 first to hexadecimal then to binary.
Show all working.
5. State three disadvantages of relays when compared with the use of PLCs in process control circuits.
6. (a) State what is meant by input and output interfaces in relation to PLCs.
(b) State briefly what the function of interfaces is in relation to the different types of process signal.
(c) The diagram of FIGURE 2 shows a bi-directional opto coupler input interface circuit. When a supply voltage of 20 V is applied the LED carries a current and 2 V is dropped across it. Calculate the value of the LED current and the value of current through the 3 k? resistance.
FIG. 2
(d) The circuit shown in FIGURE 3 is part of the interface of a relay output module. Ib is 1 mA and VCC is 9 V. The relay requires a minimum of 50 mA to energise.
Complete the values of the assumptions listed below in order to calculate:
- voltage across R1
- value of R1
- voltage across the relay coil
- voltage across R2
- value of R2
- collector of current Ic.
Assumptions:
Logic '1' = V
Logic '0' = V
Transistor forward current gain hfe =
LED current = 10 mA
LED voltage drop at 10 mA = V
Base/emitter voltage = V
Collector emitter voltage when transistor is on = 1 V
FIG. 3
|
Prepare the statement of cash flows for campo corporation
: This information is for Campo Corporation for the year ended December 31, 2017. Prepare the 2017 statement of cash flows for Campo Corporation
|
|
Is the croatian kuna overvalued or undervalued
: Starbucks in Croatia. Starbucks opened its first store in Zagreb, Croatia in October 2010. In Zagreb, the price of a tall vanilla latte is 25.70kn.
|
|
What is tesla target market
: 1. What is Tesla's target market? 2. Why did Tesla succeed in breaking into the automotive industry where so many others have failed?
|
|
What will be the dollar price of corolla at end of the year
: Corolla Exports and Pass-Through. Assume that the export price of a Toyota Corolla from Osaka, Japan is ¥2,150,000. The exchange rate is ¥87.60/$.
|
|
Write down the boolean expression for the lamp to light
: Draw the logic circuit to represent the Boolean expression using only NAND gates - Draw the logic circuit to represent the Boolean expression
|
|
Discuss effectively communicate ideas and information
: Accurately and effectively communicate ideas, information, arguments, and messages to present material in a historical context.
|
|
Review problem-casper landsten-thirty days later
: Casper Landsten-Thirty Days Later. One month after the events described in Problems I and II, Casper Landsten once again has $1 million.
|
|
Compute the fixed and variable components of travel agency
: Using the high-low method of cost estimation, compute the fixed and variable components of the travel agency's monthly operating cost
|
|
What incident caused your call to action
: What incident caused your call to action? This can be self-imposed or created by outside factors. What moment made the switch for you to take action?
|