ELEC41000: Digital Electronics Lab Assignment & Solutions

This document presents a solved digital electronics laboratory assignment focusing on fundamental concepts and logic operations. The assignment utilizes Multisim for circuit design and simulation, comparing outputs with Boolean algebra to validate the results. The solution covers various logic gates (OR, NAND, AND, NOR) and complex logic expressions, including SOP and POS forms, implemented using Karnaugh maps and Boolean reduction techniques. The assignment also explores advanced logic circuits like registers (SIPO, PIPO) and counters (modulo 10 ripple counter). The document includes detailed circuit diagrams, truth tables, and explanations for each question, demonstrating the practical application of digital electronics principles. The assignment adheres to the guidelines provided in the assignment brief for ELEC41000 Fundamentals of Electrical and Electronic Engineering module.

Running head: DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Name of the Student
Name of the University
Author Note

1DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Abstract:
Digital electronics is one of the most important branch in electronics which deals with
different types of digital signals comprising of binary values (1 and 0). The logic operations
with binary values are performed using logic gates which are different types of logic circuits
that perform arithmetic or logic operations. In this laboratory the different types of logic
operations are performed and their equivalence is measure with Boolean algebra to have the
in depth concept of digital electronics.

2DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Contents
Introduction:...............................................................................................................................4
Theory:.......................................................................................................................................4
Method:......................................................................................................................................5
Question 1a:............................................................................................................................5
Question 2a:............................................................................................................................7
Question 3a:..........................................................................................................................10
Question 3b:..........................................................................................................................12
Question 3c:..........................................................................................................................13
Question 4:............................................................................................................................15
Question 5a:..........................................................................................................................16
Conclusion:..............................................................................................................................18
References:...............................................................................................................................19

3DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Introduction:
In particular different concepts and logic operations were understood by designing
and answering the 10 questions in the laboratory. For answering the questions the logic
circuits are designed in Multisim and the output is compared with the output that is obtained
using the Boolean expression (Hassanein 2018). The truth table is also formed for each logic
expression. Efforts has been made for clear and concise representation of logic circuits and
used concepts to reduce the paper length.
Theory:
The equivalence of two logic circuits can be obtained either by using the Boolean
algebraic reduction (where De-Morgan’s theorem is used most of the times) or by obtaining
the truth table of two Boolean expressions (Gensler 2017). Now, in case of large logic
expressions it is often practised to reduce the expression into smaller format i.e. either Sum of
Product (SOP) or Product of Sum (POS) form. Now, most effective method to reduce a logic
expression in SOP or POS form is to form a Karnaugh map which is much simpler than
Boolean algebraic reduction (Prasad 2017). Now, throughout this assignment various
questions are answered using the Boolean reduction technique, the K-Map reduction,
obtaining outputs from equivalent Multisim circuits (Smessaert and Demey 2016).
Furthermore, some more advanced logic circuits register (which performs multiple bit
storage) and counter (counting) is build using Multisim. Towards the end, specifically in the
last two questions, a Serial In Parallel Out (SIPO) and Parallel In Parallel Out (PIPO) register
and a modulo 10 ripple counter have been designed using the combinational logic circuits in
Multisim.

4DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Method:
As described above the Multisim circuit design, Boolean operation and Karnaugh
Map formulation is used to answer all the questions in this assignment. The detail Multisim
circuit diagrams and the answers to the questions are given below.
Question 1a:
Figure 1: Circuit with an OR gate
VCC
5.0V
S1
Key = Space
A
S2
Key = Space
B
R1
100Ω
R2
100Ω
R4
100Ω
LED1
U2
NOT
U3
OR2
U4
NOT
A B OUTPUT
0 0 1
1 0 1
0 1 1

5DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
1 1 0
Figure 2: Circuit with a NAND gate
VCC
5.0V
S1
Key = Space
A
S2
Key = Space
B
R1
100Ω
R2
100Ω
R4
100Ω
LED1
U3
NAND2
A B OUTPUT
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6DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
0 0 1
1 0 1
0 1 1
1 1 0
Question 2a:
Figure 3: Circuit with a AND Gate
A B OUTPUT
0 0 1
1 0 0
0 1 0
1 1 0
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7DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
VCC
5.0V
S1
Key = Space
A
S2
Key = Space
B
R1
100Ω
R2
100Ω
R4
100Ω
LED1
U3
AND2
U4
NOT
U1
NOT
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8DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Figure 4: Circuit with an NOR Gate
VCC
5.0V
S1
Key = Space
A
S2
Key = Space
B
R1
100Ω
R2
100Ω
R4
100Ω
LED1
U3
NOR2
A B OUTPUT
0 0 1
1 0 0
0 1 0
1 1 0
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9DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Question 3a:
Figure 5: Constructed Circuit with Logic gates (X=((A+B) ̅ ).C)
VCC
5.0V
S1
Key = Space
A
S2
Key = Space
B
R1
100Ω
R2
100Ω
R4
100Ω
LED1
U3
NOR2 U1
AND2
S3
Key = Space
B
R3
100Ω
A B C OUTPUT
0 0 0 0
1 0 0 0
0 1 0 0
0 0 1 1
1 0 1 0
1 1 0 0
0 1 1 0
1 1 1 0

10DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
Question 3b:
Figure 6: Constructed Circuit with Logic gates (Y=AB ̅ C+A ̅ D+CD ̅ )
VCC
5.0V
S1
Key = Space
A
S2
Key = Space
B
R1
100Ω
R2
100Ω
R4
100Ω
LED1
U3
AND3 U1
AND2
S3
Key = Space
C
R3
100Ω
S4
Key = Space
D
R5
100Ω
U2
NOT
U4
OR3
U5
NOT
U6
NOT
U7
AND2
A B C D OUTPUT
0 0 0 0 0
1 0 0 0 1
0 1 0 0 0
0 0 1 0 1
1 1 0 0 0
1 0 1 0 1
1 0 0 1 0
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11DIGITAL ELECTRONICS LABORATORY ASSIGNMENT
0 1 0 1 1
0 0 1 1 1
1 1 1 0 1
1 0 1 1 1
1 1 0 1 0
1 1 1 0 1
0 1 1 1 1
1 1 1 1 0
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