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Transcript of 4 Way Traffic
TITLE PAGE
DESIGN AND CONTRUCTION OF A FOUR-WAY TRAFFIC LITHENING SYSTEM
A PROJECT PRESENTED TO THE DEPARTMENT OF ELECTRICAL/ ELECTRONICS ENGINEERING
WRITTEN BY
UBAH STEPHEN U. 08EH / 0076 / EE
UBANI INNOCENT U. 08EH / 0074 / EE
IN FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF HIGHER NATIONAL DIPLOMA OF FEDERAL POLYTECHNIC
NEKEDE, OWERRI.
SUPERVISED BY: ENGR.
AUGUST, 2010
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CERTIFICATION
This project has been accepted and approved by the Department
of Electrical/Electronics Engineering of Federal Polytechnic
Nekede, in fulfillment of the award of Higher National Diploma
(HND) certificate.
…………………………………… ………………………….. ENGR.(LADY) M.I ARIRIGUZO(MNSE) SIGNATURE/DATE PROJECT SUPERVISOR
………………………………….. ……………………………ENGR. OKONKWO CHARLES SIGNATURE / DATEHEAD OF DEPARTMENT
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DEDICATION
This project work is dedicated to God Almighty for his mercy and
empowerment throughout the accomplishment of this piece of
work.
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ACKNOWLEDGEMENT
With heart full of joy, we acknowledged the Almighty God for his
wonderfully protection and mercy throughout this work.
We will also forever remain indebted to our lovely parents and
other members of our families and friends for their immeasurable
financially and morally.
Our profound gratitude also goes to our supervisor Engr
(Lady) M.I Aririguzo (MNSE) for her pain-staking efforts and
guidance throughout this project and also to all the
Electrical/Electronics Engineering Department Lectueres.
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ABSTRACT
Four-way traffic lighting system is a signaling device positioned at
road intersections, pedestrian crossings and other locations to
control competing flows of traffic. Traffic Lights assign the right
way to road users by the lights in standard colours; Red, Amber
(or yellow) and green. In a typical cycle illumination of the green
light allows traffic to flow in the directions denoted, illumination of
the Amber light denoting prepare to stop while the illumination of
the red signal prohibit any traffic from proceeding.
This project work is composed of Five Chapters: Chapter one
introduction, traffic light location, types of traffic lights,
implementation and warrants for traffic signals. Chapter Two is on
literature review. Chapter Three is on the description of
components used, construction, circuit diagram and its
description and circuit operation. Chapter Four is on Result
analysis, testing analysis and safety rule observed when building
the system. Chapter Five is on conclusion, Recommendation and
References.
TABLE OF CONTENT
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Title Page
Approval Page
Dedication
Acknowledgement
Abstract
Table of Content
CHAPTER ONE
Introduction 1
Traffic Light Location 2
Types of Traffic light 2-3
Implementation 4
Warrants For traffic Signal 4-5
CHAPTER TWO
Literature Review 6-7
CHAPTER THREE
Description of Companies Used 8-12
Circuit Diagram 13
Power Supply Unit 14
Circuit Operation 14-15
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Parts List 15-16
Power Supply Parts list 16
Circuit Description 17-18
CHAPTER FOUR
Result Analysis 19
Test Analysis 19-20
Safety Rule Observed when Building the System 20-21
Components Precaution 22-23
CHAPTER FIVE
Conclusion 24
Recommendation 24
References 25
CHAPTER ONE
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INTRODUCTION
Traffic lights also known as stoplights, traffic lamps, stop-and-go
lights, robots or semaphore are signaling devices positioned at
road intersections, pedestrian crossing and other locations to
control competing flow of traffic. They assign the right way to
road users by the lights in standard colours (Red, Amber or Yellow
and Green).
Typically, traffic light consists of a set of three coloured light: red,
amber (yellow) and green in a typical cycle;
Illumination of the green light allows traffic to proceed in the
direction denoted.
Illuminations of the amber light denoting prepare to stop.
Illumination of the red signal prohibits any traffic from
proceeding.
In traffic light system, different countries have different
colours wit different meanings, but our major concern will be on
Nigeria Traffic Lightening system.
TRAFFIC LIGHT LOCATIONS
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Places where traffic light is needed are:-
Road Intersections.
At the landing-stage of a ferry and aboard a ferry.
At a ramp meter.
Before a drawbridge.
Before a narrowing of the road.
TYPES OF TRAFFIC LIGHTS
Traffic light can have several additional for filter turns or bus
lanes. Traffic lights are in types namely:-
Single Aspect lightening system:- This traffic light
comprises either a single or a pair of colour ed aspects that
warns any user of the shared light of a possible collision or
danger, i.e. when the lightening system is flashed Red, it
means a stop sign while when it flashes an amber sign, it
means caution, crossing or road hazard ahead.
Dual Aspects
Three or more aspects:- The universal standard is for the
red to be above the green and the amber place in between.
When mounted vertically, red is on top and when mounted
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horizontally, red is on the left. In addition to the standard
red, amber and green aspects, other aspects are usually
mounted when intersection requires more control i.e. Public
transport and Remissive turns. Traffic lights in this
configuration tends to have a delay between any entry
points to allow any residual traffic in the intersection to
clear. The delay can be dependent upon the type of
intersection, traffic and road conditions.
Pedestrian Scramble: - This is a special traffic light that
stops all vehicle traffic. Pedestrians then have exclusive
access to the intersection and can cross diagonally across
the intersection. They are useful when there is a heavy
diagonal pedestrian traffic in general. In intersections with
heavy pedestrian traffic, pedestrians have the right of
blocking drivers from turning. A pedestrian scramble gives
vehicles exclusive access to the intersection for a period of
time as well.
IMPLEMENTATION
According to transportation engineers, traffic light has both
positive and negative effects on traffic safety and traffic flow. The
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separation of conflicting streams of traffic in time can reduce the
chances of right-angle collisions. But also the frequency of rear-
end crashes can be increased by the installation of traffic lights
and they can adversely affect the safety of bicycles and
pedestrian traffic. They can increase the traffic capacity at
intersections but can also result in excessive traffic delay.
WARRNTS FOR TRAFFIC SIGNALS
Criteria have been developed to help ensure that new
signals are installed only where they will do more good than
harm. These criteria are called ‘WARRANT’. Warrants for traffic
signals are:-
Pedestrian Volume:- If the traffic volume on a major street
is so heavy that pedestrians experience excessive delay in
attempting to cross it.
Coordinating Signal System:- For places where adjacent
traffic control signals do not keep traffic grouped together
efficiently.
Roadway Network: - Installing a traffic control signal at
some intersections might be justified to encourage
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concentration and organization of traffic flow on a roadway
network.
Intersection near a Grade Crossing:- A traffic control
signal is often justified at an intersection near a railway
crossing in order to provide a pre-emption sequence to allow
traffic queued up on the tracks an opportunity to clear the
tracks before the train arrives.
School Crossing: - If there are not enough safe gaps in
traffic for school children to safely cross the street.
CHAPTER TWO
LITERATURE REVIEW
In1903, J .P Knight was the first inventor of the first traffic light.
He is a British. He was a railroad Engineer that came up with it. It
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was a lantern with red and green signals. It was put up to make
sure none would get into wrecks. It could be found in http:// www.
Answer.ask.com/consumer-electronics/ dictionaries.
William L. Poths in 1920, who was a police officer in Detroit,
Michigan. He had the idea of the first four- way, three coloured
traffic light. This could be found on http://
answer.ask.com/vehicle/other/who-invented-tra.
Alexander E. Becquerel, a French physicist, experimented with an
early type of fluorescent lighting in 1901; Peter Cooper Hewitt
received a patent for a mercury-vapour type.
Gareth Morgan and in early 1922, African-American inventor.
Gareth designed a cross-shape traffic signal, for which he
submitted a patent application on February 27, 1931.
“1886 in London” the very first traffic light was a revolving gas
lantern with red and green lights installed in a London
intersection in 1868, before the advent of automobiles. A later
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version of thee traffic light base on railroad. Http:
www.askville.amazon.com/traffic-light-invented-1868.
CHAPTER THREE
DESCRIPTION OF COMPONENTS USED
The components used and their descriptions are as follows:-
INTEGRATED CIRCUIT: This is a semiconductor device
which is composed of transistors, resistors and many other
liner devices. Semiconductor ICs used are 555 timer and
14
1
2
3
4 5
6
7
8
CD4017BP decade counter. The typical symbol of IC is
shown below:
BIPOLAR TRANSISTOR: - This is an active device that
consists of two semiconductor diodes. They are use in
switching circuit and in amplifying circuits. It has three
terminals; the emitter, collector and the base. In the circuit
above, NPN type is used as a switch, the symbol is shown as
follows;
B
E
C
15
+ -
+ -
SEMI-CONDUCTOR DIODE: - This is an active device that
conducts in one direction when the anode is anode is
typically less than positive with respect to the cathode.
Semi-conductor diode have voltage barrier of 0.70 for silicon
diode and 0.3v for Germanium. In the circuit above, silicon
diodes are used to prevent reverse bias which can destroy
the IC if it is allow occurring. The physical appearance and
the symbol is shown below;
CAPACITORS: - This is a device made up of two parallel
conducting plates separated by insulating material called a
‘DIELECTRIC’. The unit of capacitor is Farad. In this project, it
is used to control frequency or to set up an oscillation of the
circuits and also to maintain a steady voltage through the
Pin 5 of the 555 timer (IC1). Two different types of capacitor
While the symbol is
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are used in the circuit above, i.e. electrolytic and ceramic
type. Their symbols are as follows:
For electrolytic and For Ceramic
RESISTORS: - Resistors are used to limit the flow of current
in a circuit but in this project, it is used to limit current in IC2
and to control frequency in IC1. Their physical appearance
and symbol are shown bellow;
RELAY: - This is an electromagnetic device that has an
ability to open and close its contact when energized. In this
project, it is used as a switch. The symbol is shown below:
+ -
While the symbol is
N/C
Pole
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N2N1
220VAC LAMP: - This is a transducer which converts
electrical energy to light energy. In this project, it is used as
an indicator which controls the flow of traffic. The symbol is
as below:
TRANSFORMER: - This is a device that is used to transform
electrical energy. It can be step up or step down. Step down
is used in this project. The symbol is as below:
REGULATOR: - This device is used to regulate dc voltage.
12V regulator numbered LM7812 is used. The symbol is
shown below:
78xx
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LED: - Light emitting diode is used as an indicator. In this
project, it is used as a power indicator. The symbol is shown
below:
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Green Lamp OrangeLamp or Amber
RedLamp or
Green LampOrangeLamp or Amber
RedLamp or
AC Neutral
AC +220 LIVE
RL1 RL2 R4 R5 R6R3
+ Cr Cr
0.1uF
- 22uf
GND
Q1 Q2 Q2 Q2 Q2 Q2
R1 R2 R3 R4 R5 R6
D1 D2 D3 D4 D5 D6
D7
3 2 4 7 1013 8 5 15
16
14
50K555Timer
43 8
Set Switch
(NPN)
D1 – D8 = IN4007R1 – R6 = 330S2Q1 – Q6 = 2N2222
Green allows the traffic to proceed Orange (yellow) denoting prepare to stop Red denoting stop
CD4017BP
62
15
12V
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POWER SUPPLY UNIT
CIRCUIT OPERATION
The 4017 is a CMOS decade counter with 10 decoded outputs,
inputs include a clock (Pin14), a RESET (Pin 15), and a clock
INHIBIT (Pin13). The clock input drives an internal Schmitt trigger
circuit for pulse shaping and allows for unlimited clock rise and
fall times. The counter is advanced count at the rising edge of the
clock signal if the clock INHIBIT line is low. A high RESET signal
resets the counter to the zero count. This circuit is configured for
counts less than 10, 6 counts was used in this project. This was
18V240V 15A Switch
7812
+
-
1000uf35V
GND
Regulator12
Full WaveRegulator
Transformer Secondary = 9 – 0 -9
Primary 240V
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achieved by connecting Pin15 (RESET) to Pin 5 which is the 5th
count. Small signal NPN transistors are used to increase the
output current for the relays to about 20mA which is set by the
330Ώ resistors. Other NPN transistors may be substitute for the
2N2222. The 555 times generates the chock signal, the frequency
being determined by the 22uf capacitor and 50k variable resistor
which is approximately
══ 1.44 ═ 1.44
2VRC 2x50kx22x10-6
PARTS LIST:DESCRIPTION MANUFACTURING
PART NNUMBER QUANTITY COST
555 timer Lm555 1 60
4017 decade CD4017BP 1 120
50kΏ variable 50k 1 30
0.1 and 22uf cap
2 40
transistors 2N2222 6 180
330Ώ resistor 6 60
Jumper wire 2 yards 60
12volts relay 6 300
Momentary
switch
Press-make-
contact
1 50
220VAC 25W
lamp
12 720
22
Lamp holder 12 720
Rectifying
diode
6 60
Flexible wire 12 yards 360
casing 1 1500
Total #4,260
POWER SUPPLY PARTS LIST
DESCRIPTION MANUFACTURING PART NUMBER
QUANTITY COST
18V
transformer
1 350
12V regulator Lm7812 1 50
Mains lead 1 50
220VAC 15A
switch
1 60
Full wave
rectifier
4 40
1000uf/35V
capacitor
1 50
1KΏ resistor 1 10
Red LED 1 10
TOTAL 620
CIRCUIT DESCRIPTION
23
This circuit is used to illuminate four-way traffic lightening
system which is used to control traffic flow. In this operation, a
linear 3 volt (Peak to Peak) ramping waveform is generated at
Pin3 of the 555 timer IC. The 3volt waveform is transferred to
Pin14 of the CD4017BP IC which is decade counter IC. This IC has
one input Pin 10 outputs which delay its output sequentially. In
this project only 6 outputs are used, one output is used to display
or illuminate two lamps which is at opposite direction and vice
versa. The 22uf capacitor and 50k variable resistor connected to
Pin 6 and 2 of the 555 timer is used to establish the frequency
which is about 0.5HZ. This frequency is variable because of the
presence of the capacitor. Also time for the output to display is
also adjustable. The frequency and time is calculated using the
formulas;
T═ 0.69 X VR XC2
F═1.44/2VRC2
The circuit consists of two integrated circuits (ICs), that is, 555
timer and CD4017BP decade counter. 555 timer is for frequency
generation and CD4017BP is for lamp illumination of the
indicators. The illumination is carried with the help of the
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transistors which act as a switch and a relays which when
energized trigger – ON the lamps. The time and frequency can be
lengthen or alter by changing the value of VR and or C2 to higher
values for long time while lower values for lower values of VR and
C2.
25
NAZE CMMUNITY ROAD
CHAPTER FOUR
RESULT ANALYSIS
The construction is aimed at controlling traffic of a four-way
system. It is to be positioned at the center of a four-way, for an
example ‘POLY- OWERRI JUNCTION’ which is describe as below:
TEST ANALYSIS
We use 220VAC 25W lamp as an indicator, it consist of twelve
indicators. Three indicators of each side of the system is timed,
each of the indicator has its own time of display which is carried
out along with the one in opposite direction. Each display is timed
ABA ROAD
FEDERAL POLYTECHNIC NEKEDE ROAD
OWERRI TOWN ROAD
26
10seconds i.e. more indicators will stay ON for 10seconds before
the yellow indicator will indicate and vice versa.
Practically, indicators in opposite direction are connected directly
to each one with the same meaning of indication. That is RED to
RED, AMBER to AMBER and GREEN to GREEN to the one in
opposite direction. That means they will display at the same time
allowing the traffic to flow in one direction. After the construction,
the system is compose of 12 indicators, one 220VAC , 15A
switch, one reset switch, main lead (or AC cord) and a cone-
shaped casing. To test, the system when it is powered, the reset
switch is pressed to make the indicator start from more indicator.
SAFTY RULE OBSERVED WHEN BUILDING THE SYSTEM
Safety rule have been taken when the circuit was laid on the
project board first in order to achieve satisfactory result before
transferring it to the Vero board. The safety rule observed is as
follows:
a) When laying the components on the Vero board, it is
essential to keep in mind the physical size of the
components.
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b) The component must not be over crowed to avoid mistakes
in locating the component wire to the appropriate holes,
c) During the placement of the component on the Vero board,
we ensured that it was strictly placed according to the circuit
diagram and also observing the number op lead out wires
meeting at the junction in the circuit.
d) For polarized component, their polarities in the circuit
diagram must correspond to that of the layout.
e) We made sure that components used work in their non-
linearly Formby applying voltage and current which are
equal to the component rating such as 12V supply is used for
the sake of the 12V relay.
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COMPONENS PRECAUTION
Components precaution observed when building this system are:
FOR RESISTORS
Excess heat should not be applied to it as there is risk of
damaging it.
The legs of the resistors should not be over stressed in order
not to introduce internal break down.
FOR CAPACITORS
The legs should not be over stressed.
The temperature of the soldering iron should not be too high
in order not to cause damage to it such as going high in
value or leaking.
For electrolytic type, the polarity should be considered when
fixing it to vero board to avoid damage.
FOR ICS
The amount of heat used in soldering it should be considered
in order not to introduce internal distraction on it, for that
reason, socket should be applied.
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The copper foil between the legs of each pin should be open
circuited after the fixing to avoid improper operation.
FOR TRANSISTORS
* The temperature of the soldering must be considered in
order not to cause damage to it.
The configuration of the transistor must be considered.
Before the system is cased, there are other precaution we
observed, these are as follows;
It must be installed into the casing by a qualified student.
It must not be exposed to heat and moisture.
30
CHAPTER FIVE
CONCLUSION
Four-way traffic lighting system is though complex, but has in
long way help to provide desired traffic flow control for local, state
and federal roads
The idea of carrying out this project by student is a right step in
the right direction which should be encouraged.
RECOMMENDATION
Since this project is much useful to our society, which need more
attention and research. Hence, we recommend that this project
should be given to students earlier like in the beginning of the
semester to avoid much stress and pressure.
31
REFERENCES
1. The man who introduce traffic lights’. BBC. 2009-07-16.
http://www.bbc.co.uk.
2. Day, Lance; LAN MCNEIL (1996). ‘Biographical dictionary of
the history of technology’. Taylor & Frances. PP 404.5.
3. Mary Bellies (1952-02-05) . The History of Roads and
Asphalt’.
http://inventors.about.com/library/inventors/blasphalt. Htm.
4. Sessions, Gordon m. (1971). ‘Traffic devices: historical
aspects thereof Washington; institute of traffic Engineers PP.
27-28.
5. New Traffic signal installation’. www.traffic.Inst.co.uk.
6. Moyer, Sheldon (March 1997). ‘Mr. Traffic light’ motor news
(Automobile club of Michigan): 14-15, 27,
http://www33.brukster.com
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