Design And Construction Of A 4 Way Inter-Communication System

ABSTRACT

An intercom is a stand-alone voice communications system for use within a building or small collection of buildings, functioning independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles. Intercoms can incorporate connections to public address loudspeaker systems, walkie talkies, telephones.

Four-way intercommunication system is nothing but the communication within four persons not close to one another. This does not mean we should categorize telephones, fax, teleprinters, telegraphs etc. an example of intercom system since they are used in communication between people. However, intercom involves short distance places. It is limited in electronics, offices, and hospitals. This intercom system is a four-way station type. This means that a person can communicate to the other at another station at his own convenient time. They call once another attention by the use of the tone generated by the use of tone generator.

Depress a button and the tone sounds, and the same switch is thrown to the intercom circuit thus they communicate.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• PROBLEM AND LIMITATION OF THE PROJECT
• SCOPE OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• HISTORICAL BACKGROUND OF THE PROJECT
• REVIEW OF 4-WAY INTERCOM

CHAPTER THREE

SYSTEM DESIGN

• DESCRIPTION OF THE SYSTEM BUILDING BLOCK
• SYSTEM DESIGN SPECIFICATION
• BLOCK DIAGRAM OF THE SYSTEM
• DESCRIPTION OF THE OVERALL OPERATION OF THE SYSTEM
• LIST AND DESCRIPTION OF THE SYSTEM COMPONENTS
• COMPLETE CIRCUIT DIAGRAM

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

Electronic inter communication is the process of exchanging information between individuals over relatively long distance by the use of electronic system connected together by communication cables or the instrument cable or satellite links. A telephone system and an intercom system can be used to achieve intercommunication.

In the department of Electrical/Electronics Engineering, Institute of Management and Technology, Enugu, there exists the need for intercommunication between all the offices in the department so as to enable the smooth running of activities. Where by information and ideas are exchanged between the individuals concerned just at the press of a button. To achieve this kind of situation and economical means of electronic communication was considered.

Thus the intercom system was chosen so as interconnect the four offices earlier specified. Other offices can also be attached/ connected to the system as time goes on since the is room for modification. One may ask why the telephone system not considered since it is also another system of intercommunication. The telephone system is equally better but less appropriate since it requires a dedicated line form NITEL who charges bills accordingly. The intercom system only makes use of the physical communication cables interlinking the handsets concerned. Also, the telephone system requires PABX system (Private Automatic Box Exchange) for effective communication between the concerned telephone sets. The PABX is a high capacity telephone switching equipment that automatically connects a call to the desired route or extension number. It equally handles both external call and internal call. The telephone set or system is more appropriate for a whole educational complex or company. It is not appropriate to use the telephone for the connectivity of few offices as this under-utilizes the capacity of the PABX since they are designed to handle high capacity of lines. Bearing cost in mind, the 4-way intercom units is cheaper to construct when compared to the cost of procuring wireless intercom.

By embarking on the 4-way intercom, this believed that an efficient communication gadget or communication link between the offices shall be achieved.

1.2                                          OBJECTIVE OF THE PROJECT

The objective of this work is to design a device that can be used to communicate among four individuals in different parts of the home/office/industries and in the case of emergency.

1.3                                      SIGNIFICANCE OF THE PROJECT

Yelling throughout the house or office can be an annoying and inconvenient way to communicate. Using an intercom system in your home or office can save time and provide a more effective communication channel. The home intercom system provides functions ranging from convenience to security. Conversations can be held between individuals in different parts of the home and in the case of injury or emergency.

1.4                                          PROBLEM OF THE PROJECT

• When using an intercom system, anyone in the room of the sender or recipient of the message can hear the conversation. Communication might have to be repeated if static or poor sound quality exists in the intercom.
• An intercom is an electronic communications system within a building or group of buildings. They are generally composed of fixed microphone/speaker units which connect to a central control panel.
• This circuit is based upon theoretical calculations and may require practical changes to be made while implementing the circuit in hardware.
• This is designed for loudspeakers with low range and hence cannot be used at large buildings.
• This requires a changeover switch.

1.4                                        LIMITATION OF THE PROJECT

There are other different types of intercom but this particular work is limited only to a 4-way type of intercom and the circuit is powered with 12v supply.

 1.5                                       APPLICATION OF THE PROJECT

This device may find a place in pre-schools, old folk homes, boy scout/girl guide halls, churches, kids tree houses/fortresses, or maybe even more serious uses such as small offices, factories, workshops and many other applications.

1.6                             PURPOSE OF THE PROJECT

(1) The main purpose of this project is to construct a communication device that will allow communication of four different people within a particular domain, like offices homes, warehouse.

(2) To build a telephone that will transmit signal via a medium at no cost.

(3) To immensely help the engineering students understand the technology behind four way simple intercom and its practical development.

1.7                                    SCOPE OF PROJECT

The scope of this project work design of simple two way intercom system is to limited to the design, construction and test on a two station simple intercom system with specification that; I. The demodulator should operate with a minimum distortion while producing an adequate output

1. The small signal amplifier must provide an undistorted signal into the buffer amplifier to be able to drive a speaker of 8 ohms impedance.

III. A 12 volt d.c power supply is to be design and employed to power the simple intercom for operation at each station.

1. Result shall fully be discussed while suggestions for further study made.

1.8                       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 work is on the introduction to a four-way wired intercom. In this chapter, the background, significance, objective limitation and problem of a four-way wired intercom were discussed.

Chapter two is on literature review of a four-way wired intercom. 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.