AcknowledgementThe successful completion of this report is made possible with the help and guidance received

from various quarters. We would like to avail this opportunity to express our sincere thanks

and gratitude to all of them.

We are deeply indebted to our guide, Ms. D.LEELA RANI, M.Tech.,(Ph.D.),

Associate Professor, Department of ECE. We are really fortunate to associate ourselves

with such an advising and helping guide in every possible way at all stages providing time

and amenities to complete this Mini Project.

We extend our deep sense of gratitude to Prof. P.V.RAMANA, M.Tech., (Ph.D.),

Head of the Department, ECE for his moral support and valuable advices during this Mini

Project work and the course.

We thank our Principal, Dr. P.C. KRISHNAMACHARY, M.E., Ph.D., for

supporting us in completion of this Mini Project work successfully providing the facilities.

We are very much thankful to all the faculty members of the ECE department for their

good wishes and value based imparting of the theory and practical subjects, which we have

put to use in Mini Project report.

Finally, we would like to take this opportunity to specially thank our parents for their

kind help, encouragement and moral support.

E.HARESH – 12121A0422

A.SWATHI – 12121A0401

D.LEELADRI – 12121A0420

C.BHARGAVA REDDY – 12121A0413

ii

Declaration

We hereby declare that Mini Project report entitled “UNDERGROUND CABLE FAULT

DISTANCE LOCATOR” being submitted by us for award of degree of Bachelor of

Technology in Electronics and Communication Engineering, Jawaharlal Nehru Technological

University Anantapur, Anantapur is a bonafide record of the SREE VIDYANIKETHAN

ENGINEERING COLLEGE and has not been submitted to any other courses or university

for award of any degree.

E.HARESH – 12121A0422

A.SWATHI – 12121A0401

D.LEELADRI – 12121A0420

C.BHARGAVA REDDY – 12121A0413

iii

Abstract

The work is intended to detect the location of a fault in underground cable lines from the base

station in kilometers. In the urban areas, the electrical cables run underground instead of

running overhead. Whenever any fault occurs within the underground cable, it becomes

difficult to detect the exact location of the fault for the process of repairing that particular

cable. The proposed system finds the point of the exact location of the fault.

The system uses the standard concept of Ohms law, i.e., when a low DC voltage is ap-

plied at the feeder end through a series resistor (Cable lines), then the current would vary de-

pending upon the location of the short circuit fault in the cable. This system uses a microcon-

troller of the 8051 family and a rectified power supply. Here, the current sensing circuit in

combination with the resistors is interfaced to the microcontroller with the help of an ADC

device for representing the cable length in Km. The fault creation is made by a set of

switches. The relays are controlled by a relay driver IC, which is used to check the cable

line. The 16x2 LCD display connected to the microcontroller is used to display the informa-

tion.

In case of a short circuit (Line to Ground), the voltage across the series resistors

changes accordingly. It is then fed to an ADC to develop the precise digital data which is

directed to the programmed microcontroller of the 8051 family in order to display the same in

kilometers. The work in future can be implemented by using a capacitor in an AC circuit to

measure the impedance which can even locate the open circuited cable.

iv

List of ContentsPage no.

Acknowledgement ii

Abstract iv

List of Figures vii

List of Tables viii

Chapter 1 Introduction 01

1.1 Introduction to Embedded Systems 01

Chapter 2 Block Diagram 04

Chapter 3 Hardware Requirements 05

3.1 Transformer 05

3.2 Voltage Regulator 07

3.3 Rectifier 08

3.4 Filter 09

3.5 Microcontroller 10

3.6 Liquid Crystal Display 16

3.7 Analog to Digital Convertor 18

3.8 ULN2003 20

3.9 Relay 23

3.10 Diodes 25

3.11 Resistors 26

3.12 Capacitors 28

Chapter 4 Software Requirements 33

4.1 Introduction to Keil Micro Vision 33

4.2 Concept of Complier 33

4.3 Concept of Cross Complier 34

4.4 Keil C Cross Complier 34

4.5 Building an Application in µVision2 34

4.6 Creating Own Application in µVision2 34

4.7 Debugging an Application in µVision2 35

4.8 Starting µVision2 and Creating a Project 35

4.9 Window - Files 35

4.10 Building Projects and Creating a HEX file 35

4.11 CPU simulation 36

v

4.12 Database Selection 36

4.13 Start Debugging 36

4.14 Disassembly Window 36

4.15 Embedded C 37

Chapter 5 Schematic Diagram and Operation 38

5.1 Schematic Diagram 38

5.2 Operation of the Circuit 39

Chapter 6 Layout Diagram 42

Chapter 7 Algorithm and Flowchart 43

7.1 Algorithm of the Embedded System 43

7.2 Flowchart of the Embedded System 44

Chapter 8 Coding 45

8.1 Compiler 45

8.2 Source Code 52

Chapter 9 Hardware Testing 58

9.1 Continuity Test 58

9.2 Power on Test 58

Chapter 10 Result 60

Conclusion 61

Future Scope 62

References 63

vi

List of FiguresName of the Figure Page no.

Figure 1.1 Embedded System design calls 01

Figure 1.2 V Diagram 02

Figure 2.1 Block Diagram 04

Figure 3.1 A Typical Transformer 05

Figure 3.2 Ideal Transformer as a Circuit Element 06

Figure 3.3 Voltage Regulator 7805 07

Figure 3.4 Block diagram of Voltage Regulator 08

Figure 3.5 Bridge Rectifier 09

Figure 3.6 Bridge Rectifier with Filter 09

Figure 3.7 Block Diagram of AT89S52 11

Figure 3.8 Pin Diagram of AT89S52 13

Figure 3.9 Oscillator Connections 15

Figure 3.10 External Clock Drive Configuration 16

Figure 3.11 Liquid Crystal Display 17

Figure 3.12 44780 LCD Background 17

Figure 3.13 Pin Configuration of ADC0804 19

Figure 3.14 Pin Diagram of ULN2003 20

Figure 3.15 Diagram of ULN2003 21

Figure 3.16 Schematics of Darlington’s Pair 21

Figure 3.17 Darlington Pair 22

Figure 3.18 Different Types of Relays 23

Figure 3.19 Relay showing coil and switch contacts 23

Figure 3.20 1N4007 diodes 25

Figure 3.21 PN Junction Diode operation 25

Figure 3.22 Different Types of Capacitors 29

Figure 3.23 Existence of Electric Field between plates of a Capacitor 30

Figure 5.1 Schematic Diagram 38

Figure 5.2 Connections between Relay and ULN2003 40

Figure 6.1 Layout Diagram 42

Figure 7.1 Flow Chart of the Embedded System 44

vii

List of Tables

Name of the Table Page no.

Table 3.1 Ratings of the Voltage Regulator 08

Table 10.1 ADC output for various distances of Fault 60

viii