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DESIGN AND CONSTRUCTION OF MOBILE .~
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PHONE SIGNAL DETECTOR
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BY
ABIOYE OBAFEMI MICHAEL MATRICULATION NUMBER 2007/212640SEE
A FINAL YEAR PROJECT SUBMITTED TO THE DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING FEDERAL UNIVERSITY OF TECHNOLOGY MINNA, NIGER STATE.
IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF BACHELOR OF ENGINEERING (B.ENG) DEGREE IN ELECTRICAL AND COMPUTER ENGINEERING
NOVEMBER, 2011
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DEDICATION This project specially dedicated to God almighty and to my beloved family thanks for your morale support and understanding.
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DECLARATION I Mr. Abioye Obafemi Michael, hereby declare that this work was done by me and has never been presented elsewhere for the award of a degree. I also hereby relinquish the copyright to the Federal University of Technology, Minna Niger state .
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ACKNOWLEDGEMENT Thanks to God all mighty for giving me good health to undergo this project. I would like to use this opportunity to express my deep gratitude and appreciation to those people who have helped me to complete my final year project course, and to individuals to whom i am very much indebted and who, without their support, this achievement would not have been possible. First of
all , spec ial thanks to my supervisors, Mr. U.N . Galadima and Mr Bakudu Saleh for their guidance, advice and encouragement and also to Mr. A.G Raji (HOD electrical), Prof Oria Usifo and to all lecturers and lab technologies of electrical department, thank you all for imparting in me the ri ght knowled ge throughout my educational career in this school. My greatest appreciations and thanks are dedicated to my parents Mr. and Mrs. Joseph Abioye from whom i have taken the lesson of life and always prayed for my success, i am very proud of them. Also, many thanks to my friends with whom i have shared so much fun and so many good times over the past few years in my campus life especially my roommate, Jimmy Enebi and my class-mate Lawrence Emmanuel, Segun Adetayo Peter for their suggestion and help in the co mpl etio n of thi s project. Although i cannot mention them all by their names, i am grateful to
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all of them and wish them all the best. Finally, special thanks to all the members of my family Tunde, Moses, Segun, sister Tope. Mrs. Maaji. my niece and nephew Eniola Ayeni and Joseph Ayemoba, thank you very much for the warmth and kindness you all always offered me and also to my big sister Bunmi Emmuela Abioye for her support both financially and encouragements, thank you very much.
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ABSTRACT The project mobile phone signal detector presents the design of an RF detector circuit device or sensor that detects the presence of a mobile phone in active mode use in making incoming and outgoing calls as well as sending SMS messages i.e. the device senses the presence of any mobile phone activities within a distance of 3m, as the signal is detected the buzzer sounds alerting the users to switch off their mobile phones. Also in the circuit a part is design in ~Ul'h
a \\ a) th at it can be use to sw itch ON and OFF appliances i.e. as the phone is dialed it
switches ON the appliance and as it is dialed again for the second time it switches OFF. The idea is to design a circuit that detect the presence of mobile phone signal and to investigate basic electronic components involve in RF circuit design in order to test and simulate analogue RF circuit. The principle of Radio frequency and wireless communication is employed to develop the device.
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TABLE OF CONTENTS Title page ..................................................................................................... .i Dedication .................................................................................................... .ii
Declaration .................................................................................................... .iii
Acknowledgement ........................................................................................... .iv
Abstract ......................................................................................................... v
Table of content ............................................................................................... vi
List of tables .................................................................................................. vii
... · 0 ffi19ures ................................................................................................. VIlI L 1st List of abbreviations ......................................................................................... .ix Chapter One: Introduction .................................................................................... 1
1.1
Significance .... '........................................................................................ 2
1.2
Aim and objective ..................................................................................... 2
1.3
Methodology ..................................................................................... .. ... 2
1.4
Scope of work .................................... ..................................................... 3
1.5
Constraint and materials used ....................................................................... 3
1.6
Outline on thesis .................................................. ... ................. . ....... ... ..... 3
Chapter Two: Literature review ..................................................................... .... ... 4 2.1
Historical backgrounds ............................................................................. 4-5
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2.2
2.3
Theoretical backgrounds ........................................................................... 5-6 2.2.1
Integrated circuits (lCs) .................................................... ............... 6-8
2.2.2
Transistors (BJT) ........................................................................ 8-10
2.2.3
Passive components .................................................................... 10-13
limitations ........................................................................................... .13
Chapter Three: Design and implementation .............................................................. 14 3.1
Block diagram ....................................................................................... .14
3.2
Justifications of components ....................................................................... 16
3.3
3.2.1
Operational amplifier (741 Op-Amp IC) ............................................ 16-17
3.2.2
Transistor (C945) .......................................................................... .17
3.2.3
Ceramic and Electrolytic capacitors ................................................. 18-19
3.2.4
555 timer (IC) ............................................................................... 19
3.2.5
40I7B integrated circuit (lC) ............................................................. 20
circuit design for each stage ....................................................................... .20 3.3.1
RF detector circuit ..................................................................... 20-23
3.3.2 Amplification circuits .................................................................. 24-28
3.4
3.3.3
555 timer circuit ............................................................................ 29
3.3.4
Selector circuit .............................................................................. 30
3.3.5
Power supply circuit .. ; ................................................................... .31
Circuit diagram of mobile phone detector. ..................................................... 32 3.4.1
Principle of operation ................................................................ .. 33-34
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LIST OF TABLES PAGE
TABLE NO. 2.1
Light emitted by four different types of LEDs
12
3.1
properties of741 Op-Amp
17
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LIST OF FIGURES PAGE
FIGURE NO . 2.1
Op-amp symbol and schematic
7
2.2
555 timer
8
2.3
Bipolar transistor (npn and pnp)
9
2.4
Different type of resistor symbol
11
2.5
Various type of capacitors
12
2.6
Symbol of LED
13
3.1
Block diagram of mobile phone detector
14
3.2
8 pin Dip (dual-inline package)
16
3.3
Various type of ceramic capacitor
18
3.4
Electrolytic capacitor pictures
19
3.5
RF detector circuit
20
3.6
Op-amp circuit
24
3.7
Comparator circuit
25
3.8
Transistor amplifier circuit
27
3.9
555 timer circuit
29
3.10
Selector circuit
30
3. 11
Power supply circuit
31
3.12
Complete circuit diagram of mobile phone detector
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LIST OF ABBREVIATIONS DC
Direct current
MHz
Megahertz
GSM
Global System for Mobile Communications
Hz
Hertz
IC
Integrated Circuits
kHz
kilohertz
rnA
Miliampere
Op-Amp
Operational Amplifier
Vcc
supply voltage
SIP
single in-line package
Dip
dual in-line package
RF
radio frequency
SMS
short messaging system
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