Construction Of A Full-Duplex Intercom System

🔥HOT!! Get admission now directly into 200Level into the school of your choice without writing JAMB & Post UTME exam (Click Here)👈🏽 for details | Registration is On-going

👁‍🗨Download up-to-date Post UTME past questions here

Download Now

📩Get complete project / seminar material for any topic

Get Material Now

Project and Seminar Material For Electrical Electronics Engineering EEE

Project and Seminar Material For Electrical Electronics Engineering EEE


This project work is solely dedicated to the Most High God, our greatest motivator and source of inspiration.


This project of ours is an outcome of a series of combine efforts. Hence, we deem it feat to be thankful to all who contributed in one way or the other to enhance the success of this project.

An unprecedented appreciation yet an immeasurable debt go to our parents for their moral and financial empowerment.

A parallel and unalloyed heart of gratitude to our supervisor Engr, J.N Amadi, whose fatherly guidance, corrections and trouble shooting aids has made this work a reality. A profound appreciation to our project co-ordinator, Engr. Onyeje I.N who was all present for us at times of need, Our HOD Engr, Okoronkwo Charles who has input much to metamorphorsize this noble department and our noble yet a digital rector Engr. O.I Nwankwo (FNSE) for his special concern about our department and lastly a special and sincere one to our course mates-in-arms at the department, Aluta struggle, all our friends and well wishers. Thanks to you all.

Table Of Content

  • Title page
  • Certification page ii
  • Dedication  iii
  • Acknowledgement  iv
  • Table of content v-vi
  • Abstract  vii

Chapter One

  • 1.0 Introduction
  • 1.1 Preamble
  • 1.2 Intercom system
  • 1.3 Design objectives

Chapter Two

  • 2.0 The review of Related Literature
  • 2.1 Car Com
  • 2.2 Mini Gard
  • 2.3 Public III
  • 2.4 Claro
  • 2.5 Gard MC
  • 2.6 Modems
  • 2.7 Classification of modems according to operational mode
  • 2.8 Screened cable
  • 2.9 TDA 7052 BTL mono audio amplifier

Chapter Three

  • 3.0 Basic design and construction
  • 3.1 Design approach
  • 3.2 Description of individual component used
  • 3.3 System construction description
  • 3.4 Description of the system building block
  • 3.5 The Construction Techniques
  • 3.6 Comments on construction

Chapter Four

  • 4.0 Testing and trouble Shooting
  • 4.1 Introduction to Testing
  • 4.2 Component testing
  • 4.3 Testing of circuit parameters
  • 4.4 Powering the circuit
  • 4.5 Packaging
  • 4.6 Cost Analysis

Chapter Five

  • 5.0 Conclusion and Recommendation
  • 5.1 Conclusion
  • 5.2 Recommendation
  • Bill Of Quantity
  • Reference


The design of full duplex intercom system is an absolute implementation of strategic components to perfect a modern semi-conductor technology (electronics) and communications. The simple circuit design allows the two intercom stations to be operated leaving the operation free of the usual “push-to-talk” operation mode, no complex changeover switch is required.

As both microphones are always in operation, a special circuit is used to avoid that the loud speaker output is being picked up by the microphone enclosed in the same box, causing a very undesired and loud “howl” i.e. the well known “Larson effect”. A private switch allows microphone muting, if required.

Chapter One


1.0 Preamble

This project is on the design and construction of a full duplex intercom system. The design is such that the full duplex intercom will be used to enable two parties to signal and communicate with each other without interference.

1.1 Intercom System

Intercom is a short form for intercommunicating telephone. An intercom uses relating two-wire system, two for transmitting and two for reception (full duplex) and cannot be used on normal exchange lines. It is electronic communication system within a building or group of buildings.

Intercom (i.e. wireless intercom) aims to be a high quality voice communication tool use on the internet or local area networks. Intercoms are generally composed of fine microphones/speaker units which connect to central control panel. A small home intercom might connect a few rooms in a house; large systems might connect all the rooms in a school or hospital to a central office.

Intercoms in large buildings often function as public address systems, capable of broadcasting announcements.
Therefore a full duplex intercom is a situation whereby two people simultaneously talk to each other without interference or loss of signal power. Its connection is different between the door stations and the inside station.

1.2 Design Objectives

A general objective of the present invention is to provide local intercom circuit arrangement for use with and between multiple, similarly configured telephone instruments interconnected by common local cabling so as to overcome the drawbacks of an advance state of the prior art.

One specific objective of the invention is to provide a full duplex intercom arrangement by employing a dual frequency FM radio carrier talk circuit coupled to a single telephone system subscriber line (tip and ring wire pair or optical path) using two carrier frequencies sufficiently separated specifically as not to cause audible interference with each other and as not to cause interference with the use of the lines for conventional telephone communications.

Another specific objective of the present invention is to provide a full duplex intercom circuit arrangement by employing single frequency FM radio carrier talk circuits over two of the locally extending telephone company subscriber lines.

A further specific objective is to provide a full duplex intercom circuit arrangement with a frequency modulated carrier or carriers imposed locally on a telephone cable in a manner which does not cause any interference with telephone system signaling or central office equipment.

One more specific objective is to provide a full duplex intercom circuit which is easily operated, which is fully contained in a user telephone instrument, which requires very little power for operation, which may be manufactured and installed in the instrument at low cost and which has a long and reliable useful life in the telephone environment, glad to say that this is our project objective.

This material contains electrical diagrams, circuits, illustrations and more (Very detailed)

I bet you, the complete material is fully loaded. This is just an excerpt. The Material is in MS-Word Format which you can easily edit and is comprehensive for a complete research work for this topic

📩How to get the complete material

The complete material is N3,000. You are to make payment to :

Account No: 0811003731,
Bank Name: Access Bank,
Acct Name: Samphina Academy.

The mode of payment is through bank transfer or bank deposit 

After Payment

After Payment, send us the following information:

  • 📍Payment Details (For Transfer:Send the account name you transferred money from | For Deposit:Snap and send the deposit receipt)
  • 📍Project / Seminar Material you need (Topic)
  • 📍An Active Email Address

The three(3) ways in which you can send us these information are:

  • Through our email address “” 
  • Through Text Message to “08143831497” 
  • Through WhatsApp click to start chat 

After Sending your information and making payment, the material will be forwarded to you in less than 10mins via your email address

How to nail it on the head during your project defence

You are through with writing that project. Now what?

You have found yourself at that point where you have to defend what you have written. Of course you have to stand in front of your supervisor and other literary personalities to prove that you know what you wrote in your project paper. Unfortunately, the more you think about it, the more it looks like you are about to face a legion. It is not a war. But the emotion of dread welling up inside of you makes it look like one. So now you are asking yourself questions.

  • How am I going to start?
  • I hope I will do well enough to get an A.

You really want to nail it, but you need to come to terms with exactly how to get everything in perfect control. Especially your emotions of fear that seem to make a wreck of you every time you think about public speaking.
So here is the deal. I want to help you avoid that feeling that would ruin your precious moment if you dare to let it. And we are going to do it together.

I am going to highlight some very important tips to help you get in control for you to be comfortable enough to move from that feeling of DREAD to CONFIDENT; and making an awesome Impression for that great rating your supervisors should be giving to you so freely.

Consider these tips as you prepare for your defence. We will be taking them one after the other so here we go.

Watch Your Body Language And Keep It Confident:

Can you tell that a person is falling apart if they look confident? … If I can second guess you rightly, am sure you answered no to that question. Remind yourself that you need to come out that way. Now this might seem like a huge big deal when you are dealing with the foreboding. Maintaining a poise of confidence is very important. So find your most comfortable position, sitting or standing and draw up your body. You must exude confidence. It is something you need to do for yourself. People can only see what you allow your body language to show. So you must endeavour to put that out. Remember the story of David and Goliath? … At the end of your defence day, you want to be David.

Dress In Your Most Comfortable And Impressive:

Am sure this one is a no brainer. However I must highlight that you choose comfortable pieces. You don’t want to look so good and yet look like you were forced to wear something that does not belong to you. It’s great to ensure that as impressive as your clothes are on you, that they are also very comfortable.

Speak With Authority:

Going hand to hand with that aura of confidence is your most powerful asset:your words. If you look that confident, your words must not come out like whimpers. To be able to pull this off, you definitely need to speak as deliberately as possible in expressing yourself. Let them also hear what they see.

Use, Your Gestures:

I have often found this to come to my rescue in dealing with shyness and conveying my confidence. Usually it gives you an edge to also drive home your point. You must, however, ensure that you do not over use it. It doesn’t mean that your hands should be flying all over the place. That would be absolutely unnecessary. If you do this well, after a while you will realize that you are not as self-conscious as you used to be at the very start. For most situations, it would have completely disappeared altogether; leaving a really confident you talking.

Have A Good Opening And Closing Line:

Make sure you have perfected a good opening line. You should also be armed with a good closing line too. Try and rehearse it to a friend. If for the first time you presented it, your friend does not say “wow, that’s beautiful” or something like that; just know you need to keep refining it until you get the perfect line. Both opening and closing lines will go a long way in how impressed your panel gets to rate you high.

Make Sure You Know Your Work:

Certainly you should understand how important it is to know your own work from start to finish. Not having in-depth knowledge of your own work is tantamount to a suicide mission. Why should you kill yourself?
When all is said and done, this is what you came to defend in the first place. You should know your work from A to Z.

Prepare For The Questions:

Now this part is truly essential. You must be sure you do not floor all the good work you did on your presentation by not answering correctly. You must pay attention to the questions you are asked to be sure you will give the right answer. Many people get it wrong at this stage and spoil their good presentation. When you do not understand any question do endeavour to ask the person to expatiate what they mean before you answer.

These tips are by no means exhaustive, but applying these tips will give you some necessary advantage you need for a great outcome. Of course that outcome would mean that you eventually earn all your points on this project.

The structure of a good project work

Undergraduate projects in Nigeria is a prerequisite for graduation amongst Nigerian tertiary students who will which to obtain bachelors degree in their respective courses of study such as accounting, banking and finance, business administration and a host of others. Writing an undergraduate project in Nigeria for final year students entails a lot both financially and otherwise. Being able to develop any final year project depends on getting a researchable topic whether it is Accounting Undergraduate project topics, Banking and Finance research topics or banking and finance project topics and materials and it all requires diligent hard work of students who are willing to develop best undergraduate projects in Nigeria and graduate in flying colors.

A typical Undergraduate project in Nigerian tertiary institutions can be said to be divided into five or six chapters depending on the format of the school and course of study which are

1. Introduction

The introduction of an undergraduate project states the main research problem and research argument. What precisely the study is all about and why it is important. It looks at the originality of the research work and how it will fill the gap in other studies. Justification for a research undergraduate topic should not be lengthy before it has been explicitly stated.

Below are the contents in chapter one of an undergraduate research project which includes;

  • Background of the study,
  • Statement of the problem,
  • Objectives or aims of the study,
  • The research questions,
  • Research hypothesis,
  • Significance of the study,
  • Scope of the study,
  • Limitations of the study and
  • Operational definition of terms.

2. Literature review

Literature review of any undergraduate research work, be it business administration project topics or Economics project topics just to mention a few is very critical to securing a high grade in one’s project work. The literature review of a research process uncovers what other writers have written about the student’s topic. A student’s undergraduate research work should include a discussion or review of what is known about the subject and how that knowledge was acquired. The review could conclude with a brief summary of the literature and its implications. The contents of the literature review are the theoretical review, conceptual framework, empirical review and summary of literature review.

3. Research Methodology

This section includes a description of the research methods used in the undergraduate research work such as the sample size, data collection methods, measurement instruments, research data analysis procedures and the population from which the sample was selected.  This section also describes the method used in selecting the sample or samples, validation and reliability of the instruments used in the research work. There are different research statistical techniques used in undergraduate research work such as SPSS, e-views etc.

4. Results & Discussion

This section presents and discusses the data analysis results used in an undergraduate research work, the results of each analysis is being summarized, tabulated, and then discussed for each research question.  Then for each research hypothesis, the statistical test of significance selected and applied to the data is briefly described, followed by a statement indicating whether the hypothesis was supported or not supported.  In presenting the result analyses/summary in an undergraduate project tables and figures and or graph are used to add clarity to the presentation.

5. Summary, Conclusions And Recommendations

This section summarizes the findings of the study in an easy to understand manner.  It also explains the practical implications of those findings, and points to recommended directions for future research in that area.


This is where every source cited in the undergraduate research work is being included. Every undergraduate research work must be properly referenced for its authenticity.

Choosing A Good Project / Research Topic

Students in Nigerian universities these days wish to choose a very simple project topic/material. There is no issue choosing a simple project topic; the only problem is your ability to choose a good project or research topic that your supervisor will easily approve for you.

Most project supervisors really want to see how good his or her project student understands his or her surrounding through the kind of topic he or she chooses for their project work.

There are some project topic that are not reject-able; for instance in Nigeria of today; what do you think is the major issue on ground now?

If a project student can choose or craft a topic on the effect of dollar increment on the economy of Nigeria. Such project topic will be very interesting to write on.

Now what are the qualities of a good project topic?

  1. The materials for the project topic must be easily assessable.
  2. The project topic itself must be meaningful.
  3. The variables must be able to give a clear aim of the project topic.

What do I mean by variable?

Well I am deriving my point from the area of project writing; the variables here are those main words in the project topic.

Like the above project topic; the effect of dollar increment on the economy of Nigeria. You can see the main variables that really define this project topic are:dollar, increment and economy.

Before you present your topic to your project supervisor, first of all understand your project topic, and then secondly try to do some research for your topic to see if at least you can get up to 60% of what you need to write the complete project.

I said that above because you might have a very nice topic that the materials are not available online and there are no books as regard the topic; in this case the project topic becomes difficult for you even though the topic is catchy.

What do I mean by your topic being assessable?

Well what I mean is very simple and easy to understand. Simply pick your project topic, type it on google and see if you will have at least a good background for the topic you are writing on.

If you can have a good background for your project topic and you can understand the problem associated with the project topic, then I believe the aim of the project is not far-fetched.



Samuel Obiora Blessed is the CEO and founder of Samphina Academy ( a.k.a Nigeria Students Media, the youngest engineering graduate of Federal Polytechnic Nekede in 2017 and the engine brain behind this great platform. He is the man behind the scene, filled with many potentials, a musician as well as a pro developer with the interest of Nigerian students at heart.

You may also like...