ABSTRACT
T-junction traffic light controller is such a device that will play a significant role in controlling traffic at junctions, to ease the expected increased rush at such junctions and reduce to minimum disorderliness that may arise, as well as allowing the pedestrians a right of the way at intervals rather than being struck down when in a hurry to cross the roads. Such an electrical system with a touch of electronics that control the flow of traffic in a pre-determined sequential pattern at a junction, has its diagram comprising of different components. The power supply unit provides the control unit with specified voltage from primary source. The pulse generator consisting of a timer generates pulse for the system. The clock or counter moderates the signal that enters the decoding logic system. The display unit of each stand consists of led, the first is red in colour, the second is amber in colour and the last is green in colour.
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TABLE OF CONTENTS
Title Page – – – – – – – – – – – -i
Certification – – – – – – – – – – -ii
Dedication – – – – – – – – – – – -iii
Acknowledgement – – – – – – – – – -iv
Abstract – – – – – – – – – – – -v
Table of Contents – – – – – – – – – -vi
List of Figures – – – – – – – – – – -x
CHAPTER ONE
INTRODUCTION
1.1 Background of the Study – – – – – – – -1
1.2 Objective of the Project – – – – – – – – -3
1.3 Scope of the Study – – – – – – – – -3
1.4 Project Report Organization – – – – – – – -3
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CHAPTER TWO
LITERATURE REVIEW
2.1 Introduction – – – – – – – – – -5
2.2 Pre-Emption And Priority – – – – – – – -8
2.3 Special Provisions – – – – – – – – -10
2.4 Technology- – – – – – – – – – -11
2.5 Control And Co-Ordination- – – – – – – -14
2.6 Design Layout And Operation Site- – – – – – -14
CHAPTER THREE
DESCRIPTION OF SYSTEMS
3.1 The Power Supply – – – – – – – – -15
3.2 The Voltage Regulator – – – – – – – – -16
3.3 Crystal Oscillator – – – – – – – – – -21
3.4 Paper Capacitor- – – – – – – – – -26
3.5 The Microcontroller- – – – – – – – -27
3.6 System Flow Diagram- – – – – – – – -33
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3.7 Light Indicator Stage- – – – – – – – -35
3.8 Transistors- – – – – – – – – – -35
3.9 Resistors- – – – – – – – – – -41
3.10 Bridge Rectifier- – – – – – – – – -44
3.11 Electrolytic Capacitor- – – – – – – – -45
3.12 Step Down Transformer- – – – – – – -48
3.13 Seven Segment Display- – – – – – – – -49
CHAPTER FOUR
SYSTEMS OPERATIONAL UNITS
4.1 The Control Unit – – – – – – – – – -55
4.2 System Analysis – – – – – – – – -56
4.3 Choice Of Counter – – – – – – – – -56
4.4 The Interface Unit- – – – – – – – -57
4.5 Test And Result – – – – – – – – – -58
4.6 Observation – – – – – – – – – -58
4.7 Packaging- – – – – – – – – – -59
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4.8 Bill Of Engineering Measurement And Evaluation – – – -60
CHAPTER FIVE CONCLUSION AND RECOMMENDATIONS
5.1 Conclusion — – – – – – – – – -63
5.2 Recommendations- – – – – – – – -63
5.3 Suggestions For Further Research- – – – – – -64
References- – – – – – – – – – -65
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LIST OF FIGURES
Figure 1.1 Traffic light control system
Figure 3.1 Regulated power supply
Figure 3.5 The AT89C51 microcontroller circuit
Figure 3.6 System flow diagram
Figure 3.81 Transistor as a switch
Figure 3.10 The bridge rectifier
Figure 3.13 The individual segments of a seven segment display
Figure 3.14 General circuit diagram
Figure 4.1 Block diagram of a control circuit
Figure 4.7 Project package photograph
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CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
The traffic on our roads, especially intra-city traffic due to increasing number of cars grow by the day and unless adequate steps are taken to control the situation, we shall soon meet with circumstances we do not bargain for. That the innumerable traffic junctions in the country by far out-number the staff strength of the traffic wardens available and that the traffic wardens even where they are enough to control all the junctions cannot do so throughout the day is not in doubt. Traffic control at T.junctions or elsewhere ensures orderliness of movements of vehicles, goods and pedestrians while its absence strongly indicates chaos and most at times leads to accidents.
In the light of the above, it is imperative to recognize the need to compliment the physical exhausting efforts of the traffic wardens. In doing so, steps to be taken should assume permanence in nature rather than any ad-hoc exercise. Such is the role expected to be played by an installed operational road junction traffic controller.
This project –DESIGN AND CONSTRUCTION OF A THREE WAY JUNCTION TRAFFIC LIGHT CONTROLLER is such a device that will play significant role in controlling traffic at junctions to ease the expected increased rush at such junctions and reduce to minimum such disorderliness that may arise as well as allowing the
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pedestrians a right of the way at intervals rather than being struck down when in a hurry to cross the roads.
Such an electrical system with a touch of electronics that controls the flow of traffic in a pre-determine sequential pattern at a junction has its diagram below with blocks representing distinct units.[1]
Fig 1.1: Traffic Light Control System
The power supply unit provides the control unit with specified dc voltage from primary source, which is a 240v, 50Hz ac supply, from public power system. The pulse generator containing a timer generates pulse for the system. The clock or counter moderates the signal that enters the decoding logic system.
The display unit of each stand consists of three bulbs Red in colour showing STOP, three bulbs Amber in colour showing GET READY and three bulbs Green in colour showing MOVE.
1.2 OBJECTIVE OF THE PROJECT
AC Source
Dc Power Supply
Pulse Generator
Counter
Decoder
Lamp Display
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The main objective of the study includes:
5 To investigate the practicality of the theoretical knowledge about these components to be used.
6 To experiment on the compatibility of the working relation between components to be used.
7 To investigate the extent to which the design and construction of the control unit can be useful to mankind.
8 To investigate the immediate usefulness of the control system as complimentary to traffic wardens.
1.3 SCOPE OF THE STUDY
The scope of this project is to enlighten all electronics students on the use of microcontroller base traffic light (3-ways) and timer system in T-junction. On the practical usage it is limited to the laboratory used for reference purpose. The larger application of this project work is found in most of our mega cities like Abuja, Lagos, Calabar, Enugu etc, to control and manage heavy traffic congestion.
1.4 PROJECT REPORT ORGANIZATION
This report is structured to follow the history and origin of traffic light system all through the design and implementation phase. The report takes into account the step-by-step process followed in order to arrive at the final design.
Chapter one of this report introduces the concept of the Traffic light system and its objectives. Chapter two centers on the literature review, the origin and history of Traffic light systems and its basic functionality. Chapter Three explains the components which make up the Traffic light system and their basic functionalities/mode of operation. Chapter Four discusses the design procedure, construction, steps and packaging.
Chapter five handles the tests and results as well as conclusion and recommendation.
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