Design And Construction Of A 3 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.

Three way intercommunication system is nothing but the communication within three  persons not close to one another. This does not mean we should categorize telephones, fax, teleprinters, telegraphs etc. an example of intercom system sine they are used in communication between people. Infact, intercom involves short distance places. It is limited in electronics, offices, and hospitals.
The intercom system under is a three 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.

                                                             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 three offices earlier specified. Other offices can also be attached/ connected to the system as time goes on since thee 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 3-way intercom units is cheaper to construct when compared to the cost of procuring PABX system talkless of design and construction.

By embarking on the 3-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 three individuals in different parts of the home and in the case of injury or 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                                        LIMITATION 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.

1.5                                       APPLICATION OF THE PROJECT

1. This circuit can be used as a home intercom circuit.
2. It can be used at small buildings like coffee shops and small offices.
3. This circuit can also be installed in vehicles.