LAB 1 eeb341: Familiarization with logic gates PDF

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Lab report on familiarization with logic gates. This is the lab report in which student use logic gates to build simple logic circuits...

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LAB 1: FAMILIARISATION WITH LOGIC GATES. FACULTY: ENGINEERING AND TECHNOLOGY DEPARTMENT: ELECTRICAL ENGINEERING LEVEL: BEng Level 300 COURSE: DIGITAL ELECTRONICS (EEB341)

NAMES: GIFT JUMANNE LONINGO ID:201800182.

Submission:3 rd. March 2021

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TABLE OF CONTENT. 1: Introduction --------------------------------------------------- 3 2: Objectives ----------------------------------------------------- 3 3: Theory and literature Review------------------------------- 4 4: Equipment and procedures --------------------------------- 5 5: Results and analysis------------------------------------------ 6 6: Discussion --------------------------------------------------- 8 7: Recommendations -------------------------------------------9 8: Conclusion--------------------------------------------------- 9 References

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INTRODUCTION. Logic gates are the basic building blocks of any digital system. It is an electronic circuit having one or more than one input and only one output. The relationship between the input and the output is based on a certain logic. Based on this, logic gates are named as AND gate, OR gate, NOT gate etc. [1] Logic gates are important digital devices that are mainly based on the Boolean function and are used to carry out logical operations on single or multiple binary inputs and give one binary output. In simple terms, logic gates are the electronic circuits in a digital system.[2] After the introduction above this report will present the result of the experiment on logic gates and its organized into five sections. The first part is introductory section which shown at the beginning of this report which provides a very brief of description of the topic experimented. Second section will be presenting the objectives of the experiment. In third section a review of theory and literature is discussed. In the fourth section the results of the experiment are presented and in final section will presents the discussion, recommendations and conclusions arising from the results including the sources(material) which used during the experiment on the references section.

OBJECTIVES. . learn how NOT, OR and AND gates operate on logic circuit. . Learn about logic gates designing, Wire and operate logic gates such as AND, OR, NOT. . Understand how to implement simple circuits based on a schematic diagram using logic gates.

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THEORY AND LITERATURE REVIEW Logic gates are the heart of digital electronics. A gate is an electronic device which is used to compute a function on a two valued signal. Logic gates are the basic building block of digital circuits. Basically, all logic gates have one output and two inputs. Some logic gates like NOT gate or Inverter has only one input and one output. The inputs of the logic gates are designed to receive only binary data (only low 0 or high 1) by receiving the voltage input. The low logic level represents Zero volts and high logic level represents 3 or 5 volts positive supply voltage. We can connect any number of logic gates to design a required digital circuit. Practically, we implement the large number of logic gates in ICs, by which we can save the physical space occupied by the large number of logic gates. We can also perform complicated operations at high speeds by using integrated circuits (IC). By combining logic gates, we can design many specific circuits like flip flops, latches, multiplexers, shift registers etc. [3] A logic level is defined as a specific state or voltage of a signal. We know that 0 and 1 are the two states of logic gates. The logic levels 0 and 1 are known as LOW and HIGH, respectively. In digital electronics, these binary logic levels play a crucial role in data storage, data transfer. Gen erally, these logic levels can be understanding as ON and OFF states. As we said earlier, the logic levels are introduced to the logic gate by the supply voltage. If the supply voltage to the logic gate is 0 volts, it refers to Low logic level or OFF state.[3] Types of logic gates

AND gate- High if both inputs are High and Low if either or both inputs are LOW. OR gates- High if either or both inputs are high and LOW if both inputs are low. NOT gate- sometime called inverter, its false if input is true and vise verse.

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XOR gate- High if one and not both input is high. NAND gate-its Low if both inputs are high and vise verse. NOR gate-High if both inputs are low and vise verse.

APPARATUS AND PROCEDURES

.1 x 74LS04 (NOT)  1 x 74LS08 (AND)  1 x 74HC32 (OR)  1 x LED  1 x 330 resistor  1 x Breadboard

PROCEDURES.

The three IC NOT, AND and OR gate was placed on the breadboard and 5V DC power supply connected. Two separates buses were created whereby vertical lines was grounded and +5v bus. Input for all IC NOT, AND and OR were confirmed using truth table by connecting inputs of each gates to all possible combination of 0V (logical 0) and 5V (logical 1) and measuring the output voltages and each work was demonstrated to the instructor using truth table for both 2 inputs and 3 inputs of IC given above.

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RESULTS ANALYSIS. For part 1 after all connection respective to each gate, the following results were obtained. Two input Input A

Input B

Output for AND gate (A.B)

Output OR

0

0

0

gates (A+B) 0

0 1 1

1 0 1

0 0 1

1 1 1

c) NOT gate. Input

output

0

1

1

0

Three input. A

0 0 0 0 1 1 1 1

B

0 0 1 1 0 0 1 1

C

0 1 0 1 0 1 0 1

Output (A.B.C)

Output(A+B+C

0 0 0 0 0 0 0 1

) 0 1 1 1 1 1 1 1

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Part 2: Logic circuit for f (X1, X2, X3) = A 0 0 0 0 1 1 1 1

B 0 0 1 1 0 0 1 1

’

C 0 1 0 1 0 1 0 1

’

f (X1, X2, X3) =x 1.x2.x 3

f 0 0 1 0 0 0 1 1

+ x1.x2.x’3

logical circuit diagram.

DISCUSSION.

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For part 1 of the experiment depending on the logic gates with respective to the truth table. For AND gate with two input, the LED was only ON when both inputs are high (1) and OFF when either or both are LOW (0), likewise with three input, the LED was ON only if both inputs are high (1) and OFF if one or both were low (0).

Same way. For OR gate with two input, the LED turn on when both or either one of the inputs was high (1) and OFF when both inputs were low (0) and apply to three input, the LED power ON only if either of the input is high (1) but OFF if both are low (0). For NOT gate the result was come out as expected, each input was inverted when 1 or 0 applied at input terminal.

For part 2 as shown in fig 1 above, the combination of AND and OR gates were used and basically the LED turn ON only as shown on the truth table above.

RECOMMANDATION.

To be accuracy when test the output of each IC, all components especially LED, microchips, should be diagnose by testing working condition before start connecting and obtain results, also connecting wire should be shorter as possible avoiding or reducing loss of current inform of heat.

CONCLUSION. According to objective of this experiment, each expectation met successfully. Logic circuit design by using NOT, AND and OR gate was learnt successfully. Also, application of digital logic circuit design was investigated and proofed which show that logic gates used mostly in making automatic machine whereby the designer can set the conditions per user requirement or

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needs. The truth table and logic circuit diagram were used to build up the connection of all gates successfully.

REFERENCES.

[1] “Logic Gates - Tutorialspoint.” https://www.tutorialspoint.com/computer_logical_organization/logic_gates.htm (accessed Feb. 28, 2021). [2] “Basic Logic Gates - Types, Functions, Truth Table, Boolean Expressions,” BYJUS. https://byjus.com/jee/basic-logic-gates/ (accessed Feb. 28, 2021). [3] “Introduction to Logic Gates | NOT, AND, NAND, OR, NOR” Electronics Hub, Jun. 19, 2019. https://www.electronicshub.org/introduction-to-logic-gates/ (accessed Feb. 28, 2021). [4] “logic-gates-min.png (334×202).” https://physicsabout.com/wpcontent/uploads/2018/02/logic-gates-min.png (accessed Feb. 28, 2021).

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