ABSTRACT
The increasing rate of crime, attacks by thieves, intruders and vandals, despite all forms of security gadgets and locks still need the attention of researchers to find a permanent solution to the well being of lives and properties of individual. To this end, we constructed a cheap and effective security system for buildings, cars, safes, doors and gates, so as to prevent unauthorized person from having access to ones properties through the use of codes, we therefore experiment the application of electronic devices as locks. However, a modular approach was employed in the construction in which the combination lock was divided into units and each unit constructed separately before being coupled to form a whole functional system. During the construction, we conducted five testscarried out with the first three combinations being four digits number, the next two tests being five digits. From the result obtained, combinations (2), (4), (7), (8) gave the correct output combination. The general operation of the system and performance is dependent on the key combinations. The overall system was constructed and tested and it works perfectly.
TABEL OF CONTENT
Title page i
Declaration ii
Certification iii
Dedication iv
Acknowledgement v
Abstract vi
Table of content vii
CHAPTER ONE
1.0 Introduction 1
1.1 Principle of the system 2
1.2 Objective of the study 3
1.3Statement of the problem 3
1.4 Significant of the study 4
1.5 Scope of study 4
CHAPTER TWO
2.0 Literature review 5
2.1 historical development 5
2.2 Types of locks 6
2.3 Digital electronic combination locks 14
2.4 A comparison of the past solutions 16
2.5 An advancement of arguments to support the current choice 17
CHAPTER THREE
3.0 Construction, Testing, and discussion of result 20
3.1 Construction 20
3.2 Circuit diagram
3.3 The input unit 22
3.4 Component selection 22
3.5 Casing 24
3.6 Testing 24
CHAPTER FOUR
4.0 Summary, Conclusion and Recommendation 27
4.1 Summary 27
4.2 Conclusion 28
4.3 Recommendation 29
Reference 30
ix
Figure 3.1
Figure 3.2
Figure 3.3a
Figure 3.3b
Figure 3.4
Figure 3.7
Figure 4.3
Figure 4.3a
LIST OF FIGURE
1)-type flip flop 8
Schematic of D-type flip flop 9
Logic symbol 9
Schematic of JK flip flop 10
Input grounding 12
Circuit diagram 14
Casing design 16
Test procedure 17
