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. UBANI INNOCENT U. 08EH / 0076 / EE 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 1 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 HEAD OF DEPARTMENT …………………………… SIGNATURE / DATE 2 DEDICATION This project work is dedicated to God Almighty for his mercy and empowerment throughout the accomplishment of this piece of work. 3 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. ABSTRACT 4 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 Title Page Approval Page 5 Dedication Acknowledgement Abstract Table of Content CHAPTER ONE Introduction Traffic Light Location Types of Traffic light Implementation Warrants For traffic Signal CHAPTER TWO Literature Review CHAPTER THREE Description of Companies Used Circuit Diagram Power Supply Unit Circuit Operation Parts List Power Supply Parts list 6 1 2 2-3 4 4-5 6-7 8-12 13 14 14-15 15-16 16 Circuit Description CHAPTER FOUR Result Analysis Test Analysis Safety Rule Observed when Building the System Components Precaution CHAPTER FIVE Conclusion Recommendation References 17-18 19 19-20 20-21 22-23 24 24 25 CHAPTER ONE INTRODUCTION 7 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 Places where traffic light is needed are: Road Intersections. 8 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 horizontally, red is on the left. In addition to the standard red, amber and green aspects, other aspects are usually mounted 9 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 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 10 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 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 11 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 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. 12 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 version of thee traffic light base on railroad. Http: www.askville.amazon.com/traffic-light-invented-1868. 13 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 CD4017BP decade counter. The typical symbol of IC is shown below: 14 1 2 3 4 8 7 6 5 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; C B E 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 15 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; + + - While the symbol is 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 are used in the circuit above, i.e. electrolytic and ceramic type. Their symbols are as follows: + - 16 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; While the symbol is 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: N/C Pole 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: 17 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: N1 N2 REGULATOR: - This device is used to regulate dc voltage. 12V regulator numbered LM7812 is used. The symbol is shown below: 78xx LED: - Light emitting diode is used as an indicator. In this project, it is used as a power indicator. The symbol is shown below: 18 12V D1 – D8 = IN4007 R1 – R6 = 330S2 Q1 – Q6 = 2N2222 16 8 43 50K D1 R1 D7 Cr 0.1uF + Cr Q1 22uf Q2 14 3 D2 R2 Q2 Set Switch (NPN) CD4017BP 2 D3 R3 4 D4 R4 Q2 7 D5 R5 15 5 10 8 13 D6 R6 555 Timer 6 2 5 1 Q2 Q2 RL1 RL2 R3 R4 R5 R6 GND AC + 220 LIVE AC Neutral Green Lamp Green Orange Red Lamp or Lamp or Lamp Amber Orange Lamp or Amber Red Lamp or Green allows the traffic to proceed Orange (yellow) denoting prepare to stop Red denoting stop 19 POWER SUPPLY UNIT Regulator 240V 15A Switch 18V Full Wave Regulator 7812 12 + 1000uf 35V Transformer Secondary = 9 – 0 -9 Primary 240V GND 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 achieved 20 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 2VRC ═ 1.44 2x50kx22x10-6 PARTS LIST: DESCRIPTION MANUFACTURING QUANTITY PART NNUMBER 555 timer Lm555 1 4017 decade 50kΏ variable CD4017BP 50k 1 1 2 6 6 2 yards 6 Press-makecontact 12 12 21 COST 60 120 30 40 180 60 60 300 50 720 720 0.1 and 22uf cap transistors 2N2222 330Ώ resistor Jumper wire 12volts relay Momentary switch 220VAC 25W lamp Lamp holder 1 Rectifying diode Flexible wire casing Total 6 12 yards 1 60 360 1500 #4,260 POWER SUPPLY PARTS LIST DESCRIPTION 18V transformer 12V regulator Mains lead 220VAC switch Full rectifier 1000uf/35V capacitor 1KΏ resistor Red LED TOTAL 1 1 10 10 620 1 50 wave 4 40 15A Lm7812 1 1 1 50 50 60 MANUFACTU RING PART QUANTITY NUMBER 1 COST 350 CIRCUIT DESCRIPTION 22 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 transistors which act as a switch and a relays which when 23 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. 24 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: NAZE CMMUNITY ROAD OWERRI TOWN ROAD ABA ROAD FEDERAL POLYTECHNIC NEKEDE ROAD 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 25 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. b) The component must not be over crowed to avoid mistakes in locating the component wire to the appropriate holes, 26 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 nonlinearly 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. 27 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. The copper foil between the legs of each pin should be open circuited after the fixing to avoid improper operation. 28 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. 29 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. 30 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 Asphalt‟. (1952-02-05) . The History of Roads and 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 31