ABSTRACT
An audio amplifier is a device for
increasing the audio power of a signal by use of an external source, it is
designed to meet up with the amplification demand in concerts and for
adresssing large number of people and for musical system. The circuit is
designed for stereo sound system.This device is designed to deliver appreciable
power to load. Audio amplifier may be called upon to supply power ranging from
few watts in an audio amplifier to many hundreds and thousands of watts to a
load (speaker). In audio amplifier the load is usually the dynamic impedance
presented to the amplifier by the power delivered to the load over a wide range
of frequencies. The power amplifer in a radio transmitter operates over a
relatively narrow band of frequencies with the load essentiallyconstant
impedance.
TABLE OF CONTENTS
PAGES
Title Page i
Certification ii
Dedication iii
Acknowldegement iv
Asbtract v
Table of Contents vi
CHAPTER ONE: INTRODUCTION
1.1 Background
of the Project 1
1.2 Statement
of problem 3
1.3 Purpose
of the project 4
1.4 Significance
of the project 4
1.5 Scope
of the project 5
1.6 Limitation
of the project 5
CHAPTER TWO:
LITERATURE REVIEW
2.1
Introduction 6
2.2
Materials Used 8
2.3 Transformer 9
2.4
Capacitor 10
2.5 Transistor 11
2.6 Diode
12
2.7 Resistor 13
2.8
Mosfet 14
2.9 Light emitting diode 15
2.10
Fuse 16
2.11
Switch 17
2.12
Heat sink 18
2.13 Intergrated circuit 19
2.14
Vero Board 19
CHAPTER THREE: RESEARCH
METHODLOGY
3.1
Preliminary Ideas 20
3.2
Selection Process 20
3.3
Operational Stage 20
3.4
Construction 23
3.5
Sequence of Operation 23
CHAPTER FOUR
4.1
Testing 26
4.2
Safety Precautions 27
4.3
The amplifier Housing/casting 27
4.4
Faults in amplifier 29
CHAPTER FIVE: SUMMARY, CONCLUSIONS AND
RECOMMEDATIONS
5.1 Summary 32
5.2 Conclusion 32
5.3 Recommendation 33
References
CHAPTER ONE
INTRODUCTION
1.1 Background of the
Project
It is essential to have an historical
perspective of live music amplification and public address including the trends
that shaped how amplified music is heard if we wish to be in command of how we
manage it. The following is an abridged overview of the background of an
amplifier.
Many centuries back people found it
difficult to be heard over some few meters away from them while addressing
their audience. If a crowd of twenty to thirty thousand are to be addressed
together, then the person addressing have to go through stress. Some means were
also involved in order to solve this problem of being heard from long distance,
in the case of addressing a very large croud some people were placed at
strategic point. And at times the group is shared into hundreds for
convenience sake, and after addressing them he starts all over again with the
other group with the same message but still yet it was not easy and it was altogether rigorous. Not all performers
express interest in how they are heard by their audience. This motivated the
need for more research and for man to pursue a new technologies which will
increase his reliability and efficiency. This will actually involve passing
information energy over distance by electrical means. Man in search of the audio
boosting instrument developed an aspect of communication called “Public Address
System (PAS)”, which helps an individual to address or communicate to a large
group of people. Public Address System as its name implies is a system whereby
an impute (voice through a microphone) is connected to the output (amplifier)in
order to increase what was initially sent to the system. For instance a clergy
man can address his congregation, an entertainer such as singer can communicate
to his\her audience, a politician can address his supporters and so on. The
Public Address System (PAS) comprises of a microphone which converts sound
energy to electrical energy, an amplifier which increase the strength of the
electrical signals and a loudspeaker which reconverts the electrical energy of
the signals to sound energy. In the PAS, the sound energy at the loudspeaker has
greater power than at the microphone hence, the sound is more louder. This
reduces the stress of the
individual using the microphone from shouting. The power output of the speaker
depends on the power rating of the loudspeaker and that of the amplifier.
Moreover, an amplifier may be defined
as a system or an electronic circuit which accept signals at its input and
gives out signals at its output greater than the signal at its input in
amplitude or power or current. The output signal is similar to the input signal
in shape, form and frequency.
To amplify means to make bigger. English
dictionary explains amplify as to render something larger, more extended and or
intense and to increase the amplitude of something.
Amplifier according to English
dictionary: means any thing that renders larger or more intense or an
appliance or circuit that increases the strength of a weak electrical signal
without changing the other characteristic of the signal.
Therefore an audio amplifier is a
device that accepts a varying input signal and produces an output signal that
varies in the same way as the input but has a larger amplitude. The input
signal may be a current, a voltage, a mechanical motion or any other signal; the
input signal is usually of the same nature.
In a device such a radio receiver,
several amplifier boost a weak input signal until it is powerful enough to
drive a speaker.
1.2 Statement of
problem
Since information must be passed from
one place to another and being heard effectively and clearly is the major
problem in communication, because to say that a meaningful communication has
taken place is to say that what is produced from the voice is clearly heard by
the audience. Also in the case of entertainment, eg ;musical concert, what is
sang must be heard by the people in attendant and not just 50 people or 100 but
at times it ranges from 1000 to 20,000,ordinary voice will not do for such
task.
Then the problem therefore is lack of
device that will make louder the voice and music for a larger number of people
(up to about 20000) either in the church, mosque, musical concerts or seminar to
hear very clearly and audibly.
1.3 Purpose of the
project
Therefore the purpose of this project is
to construct a reliable 1000watt Audio amplifier that is suitable for
addressing a large number of people and that can be effectively produce even in
this depressed economy. In other words, this project is intended to eradicate the
problem that is faced concerning audibility of words, and to amplify all the
audio signals from the microphone and any other source of sound connected to it
and to provide solution to most of problems being faced by the audience.
1.4 Significance of
the project
This project is very useful because of
its significance, it is designed in order to handle and cover a very big
occasion that its attendance is large and it would be able to carry up to about ten (10) loudspeaker
conveniently. It would be very useful in bringing out the best sound that is suitable
to human hearing .And in order to to save the stress that is passed through
when addressing large number of people. This project is also durable and not too
heavy, therefore it can be moved from place to place easily.one other
significance of this project is that it is cheap and economical to produce.
1.5 Scope of the
project
The scope of this project covers the
design and construction of an audio amplifier which will form part of Public
Address System (PAS)and help in good sound production by increasing input
signal which is originally received.
1.6 Limitation of the
project
The actual voltage for which it was
designed is what should be used, because anything greater than that will cause
overheating and will eventually result in damage of the component.
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