DESIGN AND CONSTRUCTION OF AN ELETRONIC DIGITAL DISPLAY SYSTEM (MOVING MESSAGE DISPLAY)

By

OKONKWO IKECHUKWU INNOCENT UGOCHUKWU

Presented To

Department of Science Laboratory Technology

Abstract

The aim of this project work is to design and construct an electronic digital display system, based on light-emitting diodes connected in an array that forms the information to be displayed i.e. "GREAT NIGERIAN STUDENTS". This project is useful for creating attention - getting messages, presentations, advertisements and location identifiers. The system consists of power supply unit, oscillator unit, counter unit, driver unit and output unit. The power supply unit uses alternating current (AC) from the mains which will be stepped down to 12V using a step-down transformer, rectified with bridge rectifier, filtered with the actual capacitor and regulated to 9 volt using an IC regulator. The oscillator unit contains a 555 timer IC set as astable multivibrator used to produce clock pulses for the counter unit which contains 4017 decade counter IC. The 4017 counter enables the information to be displayed sequentially as desired. The driver unit uses transistor to amplify the signal strength of the counter's output. The output unit enables the information to be displayed using light emitting diodes (LEDs).

Table of Contents

Title page

Certification

Dedication

Acknowledgement

Table of contents

List of plate

List of table

List of figures

Abstract

CHAPTER ONE: INTRODUCTION

11 Background of the problem

12 Statement of the problem

13 Objectives of the study

14 Significance of the study

15 Scope of the study

16 Research questions

CHAPTER TWO : LITERATURE REVIEW

21 Component description

CHAPTER THREE : MATERIALS AND METHODS

31 Power supply unit

32 Oscillator unit

33 Counter unit

34 Driver unit

35 Output unit

36 Description of Electronic Digital Display System

CHAPTER FOUR

40 Results

CHAPTER FIVE : DISCUSSION, CONCLUSION AND RECOMMENDATION

51 Discussion

52 Conclusion

53 Recommendations

Cost of Construction

REFERENCES

List of plate

Plate 1: The photograph of the constructed electronic digital display system

List of tables

Table 1: Experiments carried out and their frequency

List of figures

Fig 21: Symbol of a transformer

Fig 22: Circuit symbol of bridge rectifier

Fig 23: Symbol of a polarized and non-polarised capacitors

Fig 24: Symbol of a diode

Fig 25: Symbol of a LED

Fig 26: Circuit diagram of rectifier diode and LED connected in

parallel

Fig 27: Pinout connection of 7809IC

Fig 28: Symbols of fixed and variable resistors

Fig 29: Symbols of transistor

Fig210: Pinout diagram of 555 timer

Fig211: Pin connection of 4017 decade counter

Fig212: Diagram of a veroboard

Fig 31: Block diagram of electronic digital display system

Fig 32: Circuit diagram of full wave rectification

Fig33: Circuit diagram of a 9 volt regulated power supply

Fig34: Circuit diagram of astable multivibrator

Fig 35: Complete circuit diagram of electronic digital display

System

Chapter one

INTRODUCTION

11 Background of the study

Electronic digital display system as used in this reports refers to a sign that uses electronic hardware and software to display its copy, messages or images Also, a sign utilizing a fixed light source to provide a message in text, images pictures, and / or symbols that may appear to move or may appear as on/off messages This is contrast to traditional non-electronic signs where the copy displayed is physically applied to the sign surface by printing, painting or otherwise attaching it onto the sign The materials or substrate to which the copy is applied is typically paper, wood, plastic or the wall of a building

In this modern time, solid materials have helped man to show that he really exists by doing wonders in the world of electronics One major development, made possible by the enormous advances in solid state technology, is the "digital revolution" Circuits are designed to implement the basic digital logic functions fundamental to all digital systems Digital electronics therefore comprises the design, manufacture and use of circuits for processing information in digital form (Simpson, 1978)

An information display is a way of providing information and it is also used as an object for promotion It can be seen in a form of cardboard or tarpaulin at stores / shops, sign posts, placards, notice boards and electronic display boards But the advent of new technologies has made the information in the form of an electronic display in the world of advertisements and promotions (Gupta, Shukla and Nagwekar, 2013) The ability to display a short message can be useful application to be available for any business Electronic digital display system is perfect for this application It can be used for both indoor and outdoor which makes it universal fit for any business or event Electronic digital display system is very efficient and cost effective way to spread messages to thousands of people, without any personal contact or door to door sales Light-Emitting Diode (LED) is a solid state light source with several attractive properties for display application LED is a diode that gives off visible light when forward biased (Mehta and Mehta, 2014) It is chosen as the main component for displaying messages because, today LED is the most energy efficiency example and other useful systems

The birth of signs and display can be said to be as old as the existence of man on the planet earth From the beginning of the world, different types of displays have been in use, each mode to serve the purpose of invention efficiently Signs are any kind of visual graphics created to display information to a particular audience (David, 2013) In 1389, King Richard II of England compelled landlords to erect signs outside their premises (Manton, 2008) In ancient Rome, signboards were usually made from stone or terracotta (Chris, 1995)

With the advancement in technology, man started carving woods and trees The use of special dyes on wood as a means of identifying special locations With the discovery of Bronze and iron, man started using the materials to display sign, thus the advent of metal sign boards were born, which are mostly used in developing countries On semiconductors and vacuum tubes technology, light displays and sign boards were built to add more beauty in the old system and as a way to increase visibility LED technology is frequently used in signs now instead of Neon signs, introduced in 1910 at the Paris Motor show (Bellu, 2006) The use of electronic is now becoming very important It is extensively applied in almost our day to day activities

Electronic digital display system is also used for outdoor advertisement Before, outdoor advertising was mainly characterized by the use of paper Every bus stop and billboard had a paper advertisement inside The reason for this was simple paper was easy to use and extremely cheap It had some draw backs as well Before an image is actually on the street, it first has to be printed, pasted and placed The journey from design to placement is quite long Another disadvantages is the considerable amount waste generated by the use of paper Finally, many people ignore a paper advertisement and there attention is drawn to the vibrant environment around them and not to a still image

The extent of development in information dissemination has made it possible that the well known method of displaying information using sign posts, notice boards, etc has to be modified by using electronic digital display system In today's rapidly advancing technology market, most conventional digital display system are not being implemented using individual logic gates and integrated circuits (ICs) such have been used in the past instead, programmable devices such as microprocessor and microcontroller chips which contain the circuitry necessary to create logic functions are being used to implement digital systems The use of 555 timer as a stable multivibrator and decade counter (CD4017) can be used to build less expensive electronic display system The use of these two major ICs will bring about less board space, less power consumptions and overall, low cost in manufacturing

This project however; emphasizes mainly on the display of information using two major integrated circuits (ICs) namely NE555 timer (ICI) and CD4017 (IC2) to control the lighting of LEDs This message display circuit is built around readily available, low cost components It is easy to fabricate A total of 250 LEDs will be used to display the message "GREAT NIGERIAN STUDENTS"

12 Statement of the Problem

Due to limitation of the sign board or local sign board which could not display clearly at night expect light shines on it, it is then necessary that electronic display system is employed to counter the limits of the local sign board The information displayed on the local sign board is less attractive compared to the information displayed using electronic digital display system

Thus, researchers are prompted to tirelessly hold up to these challenges by initiating some means of improving the above among which is the design and construction of an electronic digital display system

13 Objectives of the Study

The main objective of this study is to design and construct an electronic digital display system Specifically this study will achieve the following:

i To display "Great Nigerian students"

ii To use the electronic digital display system constructed as a sign post for federal polytechnic, Oko

iii To have more knowledge on what electronic digital display system is all about

v To know the benefits of electronic digital display system

v To design and realize the moving message display panel

14 Significance of the Study

In all field of human endeavour, electronic digital display system plays very vital role, such as means of advertisement, means of communication, presentations, exhibitions, identification and direction It is also used in giving warning or safety instructions, such as warning signs, traffic signs, exit signs or signs conveying rules and regulations This project write-up will be a guide to future designing in a related work

15 Scope of the Study

This project covers the use of peripheral solid state electronic components alongside with two major integrated circuits (ICs) namely NESSS timer and CD4017 decade counter to solve above stated problems It is limited to display GREAT NIGERIAN STUDENTS

16 Research Questions

This research will try to provide answers to the following research questions:

1) What is electronic digital display system?

2) How can electronic digital display system be constructed?

3) What are the users of electronic digital display system?

4) What are the benefits of electronic digital display system?

5) What kind of content that can be shown on electronic digital display system?