Amplifiers, which are devices that increase the gain of an audio signal, dominate modern audio technologies. In this project, we designed and built an audio amplifier from scratch in order to demonstrate that such a key device can be constructed using basic electrical engineering principles.

After performing major circuit calculations by hand, we modeled our circuit in PSpice, which is computer software that analyzes electrical circuits. In particular, we studied the variance that using budget electrical components introduced into the circuit overall by comparing three different amplifiers that we constructed.

We found the variance between the three amplifiers to be minimal, confirming our method of building a low budget, low power audio amplifier.

INTRODUCTION

Many centuries back people found it difficult to be heard over a few metres away from them while addressing their audience. This motivated the need for man to pursue new technologies which will increase his reliability and efficiency. 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. Through this system for instance, a clergyman can address his congregation, an entertainer can communicate to his 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 increases 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 that 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 accepts signals at its input and gives out signals at its output grater 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

TABLE OF CONTENT

Title page certification

Certification

Acknowledgement

Abstract

Table of content

CHAPTER ONE:

Introduction

Objective of study

Scope of Study

Background of Study

Definition of terms

CHAPTER TWO:

Background

Circuit Components

Classes of Amplifiers

Negative Feedback

CHAPTER THREE:Methodology

Design Requirements

CHAPTER FOUR:

Theoretical Design

The First Stage

The Second Stage

The Output Stage

Computer Simulation

Lab Work

Final Assembly

CHAPTER FIVE: 

Results

CHAPTER SIX:

Conclusion 

References