Design And Construction Of A Telephone

DEDICATION

This project is dedicated to Almighty God for his protection, kindness, strength over my life throughout the period and also to my — for his financial support and moral care towards me.Also to my mentor — for her academic advice she often gives to me. May Almighty God shield them from the peril of this world and bless their entire endeavour Amen.

ACKNOWLEDGEMENT

The successful completion of this project work could not have been a reality without the encouragement of my — and other people. My immensely appreciation goes to my humble and able supervisor Mr. — for his kindness in supervising this project. My warmest gratitude goes to my parents for their moral, spiritual and financial support throughout my study in this institution.
My appreciation goes to some of my lecturers among whom are Mr. —, and Dr. —. I also recognize the support of some of the staff of — among whom are: The General Manager, Deputy General manager, the internal Auditor Mr. — and the —. Finally, my appreciation goes to my elder sister —, my lovely friends mercy —, —, — and many others who were quite helpful.

ABSTRACT

This project work is on a telephone. A telephone is an instrument that transmits voice over a distance. A person can talk and communicate with another person at distant place with the use of a telephone. A telephone is a device that converts the human sound into a form that is transmittable through wire or radio technology, and reproduces it at a far away place in an audible format.  A telephone receives the voice of one person through the microphone, transmit it over long distance in a way that the receiver can listen to the voice through the speaker provided with the telephone.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
TABLE OF CONTENT

CHAPTER ONE

1. INTRODUCTION
2. BACKGROUND OF THE PROJECT
3. AIM/OBJECTIVE OF THE PROJECT
4. SIGNIFICANCE OF THE PROJECT
5. SCOPE OF THE PROJECT
6. LIMITATION OF THE PROJECT
7. PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW
2.0      LITERATURE REVIEW
2.1      BASIC PRINCIPLES OF LANDLINE TELEPHONE SYSTEM
2.2     DETAILS OF OPERATION LANDLINE TELEPHONE
2.3     HISTORICAL BACKGROUND OF THE PROJECT
2.4     GRAPHICAL SYMBOLS USED TO DESIGNATE TELEPHONE

CHAPTER THREE

SYSTEM DESIGN

• SYSTEM BLOCK DIAGRAM
• SYSTEM OPERATION
• CIRCUIT DIAGRAM OF THE SYSTEM
• PARTS LIST
• CIRCUIT DESCRIPTION
• SYSTEM DESIGN NOTES

CHAPTER FOUR

• IMPLEMENTATION, TESTING AND RESULTS
• CONSTRUCTION PROCEDURE AND TESTING
• INSTALLATION OF THE COMPLET DESIGN
• CASING AND PACKAGING
• ASSEMBLING OF SECTIONS
• TESTING OF SYSTEM OPERATION
• PROBLEM ENCOUNTERED

CHAPTER FIVE

• COST OF ANALYSIS
• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals suitable for transmission via cables or other transmission media over long distances, and replays such signals simultaneously in audible form to its user.
The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice in a distant location. In addition, most telephones contain a ringer which produces a sound to announce an incoming telephone call, and a dial or keypad used to enter a telephone number when initiating a call to another telephone. Until approximately the 1970s most telephones used a rotary dial, which was superseded by the modern DTMF push-button dial, first introduced to the public by AT&T in 1963. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The dial may be located either on the handset, or on a base unit to which the handset is connected. The transmitter converts the sound waves to electrical signals which are sent through the telephone network to the receiving phone. The receiving telephone converts the signals into audible sound in the receiver, or sometimes a loudspeaker. Telephones permit duplex communication, meaning they allow the people on both ends to talk simultaneously.

1.2                                         BACKGROUND OF THE PROJECT
In 1876, Scottish emigrant Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice. This instrument was further developed by many others. The telephone was the first device in history that enabled people to talk directly with each other across large distances. Telephones rapidly became indispensable to businesses, government, and households, and are today some of the most widely used small appliances.
The first telephones were directly connected to each other from one customer’s office or residence to another customer’s location. Being impractical beyond just a few customers, these systems were quickly replaced by manually operated centrally located switchboards. This gave rise to landline telephone service in which each telephone is connected by a pair of dedicated wires to a local central office switching system, which developed into fully automated systems starting in the early 1900s. For greater mobility, various radio systems were developed for transmission between mobile stations on ships and automobiles in the middle 20th century. Hand-held mobile phones was introduced for personal service starting in 1973. By the late 1970s several mobile telephone networks operated around the world. In 1983, the Advanced Mobile Phone System (AMPS) was launched, offering a standardized technology providing portability for users far beyond the personal residence or office. These analog cellular system evolved into digital networks with better security, greater capacity, better regional coverage, and lower cost. The public switched telephone network, with its hierarchical system of many switching centers, interconnects telephones around the world for communication with each other. With the standardized international numbering system, E.164, each telephone line has an identifying telephone number, that may be called from any authorized telephone on the network.
Although originally designed for simple voice communications, convergence has enabled most modern cell phones to have many additional capabilities. They may be able to record spoken messages, send and receive text messages, take and display photographs or video, play music or games, surf the Internet, do road navigation or immerse the user in virtual reality. Since 1999, the trend for mobile phones is smartphones that integrate all mobile communication and computing needs.

1.3                                             OBJECTIVE OF THE PROJECT
The objective of this work is construct a device that permits two or more users to conduct a conversation when they are too far apart to be heard directly by converting sound – most efficiently the human voice, into electronic signals suitable for transmission via cables.

1.4                      SCOPE OF THE PROJECT
Telephone is a device that is used to transmit the sound at long distances from its source. In the world there are approximately 400 million telephones used in the world. Handsets and the telephones used worldwide are almost the same. In a telephone sound waves are converted into the electrical oscillations (slightly swinging) and then again turned into the sound waves when reach to the receiver. This oscillation can travel 900,000 times faster than the sound waves. In the mouth piece of a telephone set, there is small transmitter that transmits the sound, produced by the speaker, into vibrating air molecules, generated through speech, that creates the vibration into the electrical diaphragm (disc that creates sound).This vibration is transmitted into a piston that is a metallic box filled with granules of carbon. Sound waves are again converted into electrical signals which are converted back to the sound waves at the ear piece.
The loudspeaker and microphone work in similar but opposite ways. The microphone contains a flexible piece of plastic called a diaphragm with an iron coil attached to it and a magnet nearby. When you speak into the mouthpiece, the sound energy in your voice makes the diaphragm vibrate, moving the coil nearer to or further from the magnet. This generates an electric current in the coil that corresponds to the sound of your voice: if you talk loud, a big current is generated; if you talk softly, the current is smaller. You can think of a microphone as an energy converting device: it turns the sound energy in your voice into electrical energy. Something that converts energy from one form to another is called a transducer. The loudspeaker in a phone works in the opposite way: it takes an incoming electrical current and uses magnetism to convert the electrical energy back into sound energy you can hear. In some phones, the loudspeaker and microphone units are virtually identical, just wired up in opposite ways.

1.5                                         SIGNIFICANCE OF THE PROJECT

Easy and quick to use: Telephone is really very easy to use as well as it very much quick for this advantage of telephone it is very popular amongst every class of people.
Easy and available means of communication: Communication through telephone is really very easy and available because most of people now use telephone and any time and any where you can connect to any one if you have the number of your expected person.
Less expensive: Less expensive is the other great advantage of telephone. Telephone is much less expensive then other communication process.
Distance is not a matter: Distance is not a matter for communication if you have a telephone. You can communicate with a person even if he stay other side of the world. Can communicate as no matter what the distance is.
No barrier: A phone call can reach to any location where there is barrier for physical appearance.
Tracking system: Legal law and enforcement organization can detect any one by telephone. It helps them to find our criminal easily.
Games in mobile phone: You can enjoy your lazy time by playing game in mobile phone. There are various kinds of games which is provided to mobile phone set.

1.6                                           LIMITATION OF THE PROJECT

Physical Damage: In long term use it cause headache and permanent damage of brain specially when it is mobile phone.
Often use for threat: One of the greatest disadvantage of telephone is it is often used for threat for various purpose.
Network problem: Because of network problem we cannot talk properly sometime and this is very annoying limitation of telephone.
Use for criminal activities: Telephone is often used for criminal activities because criminal use telephone for its various advantages
Waste huge time of teens: Undoubtedly telephone is really play a vital role for various purpose including business but telephone west huge time of teens. Often they chat long time with there friend and waste their valuable time of study.
Use for sexual harassment: As I said before criminal use telephone for its huge advantages like this some people often use telephone for sexual harassment.
Often it cause miscommunication: Some time telephone cause miscommunication among people like some misunderstanding because of same word.
Miss call: Though number of miss call goes down but still now some time call goes to wrong number and this is very disturbing some time.
Habit of laying: Telephone and mobile increase the habit of laying in society because people of the other side cannot judge.
Absence of face to face conversation: Telephone cannot provide face to face conversation and this is one of the most common limitations of telephone.
Voice is not clear some time: Some time voice can’t come clearly because of network problem or system fault.

1.7                          PROJECT WORK ORGANISATION
The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:
Chapter one of this works is on the introduction to telephone. In this chapter, the background, significance, objective limitation of a telephone was discussed.
Chapter two is on literature review of telephone. In this chapter, all the literature pertaining to this work was reviewed.
Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.
Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.
Chapter five is on conclusion, recommendation and references.

PROJECT DESCRIPTION

Format = Microsoft word

Chapters = 1-5 chapters

Price: N3,000.

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