ABSTRACT
This thesis gives the account for the design and construction of a 45W Audio Power Amplifier with the objective of producing a reliable and cheaper amplifier that can be used in a household or stage.
The Audio Power Amplifier was constructed with electrical/electronics components such as resistors, capacitors, transformer, transistors and so on. Many tools/instruments like soldering iron, multimeter and so on were used.
The 45W Audio Power Amplifier when compared with other types of Audio Power Amplifier of the same rating in the market is cheaper as the components and materials used were locally sourced and selected to suit the desired purpose and environment.
LIST OF TABLES, GRAPHS AND FIGURES
Figure 1.1 circuit diagram of a 25W Audio Power Amplifier
Figure 2.1 Resistor colour band table
Figure 2.2a Colour code marking on a resistor
Figure 2.2b Circuit symbol of resisitor
Figure 2.3 Circuit symbols of capacitor
Figure 2.4 Diode circuit symbol
Figure 2.5a Formation of potential barrier
Figure 2.5b Forward biasing a P-N junction diode
Figure 2.5c Reverse biasing a P-N junction diode
Figure 2.6a Structure and symbol of p-n-p and n-p-n transistor
Figure 2.6b Biasing of a transistor
Figure 2.7 Structure of an IC
Figure 2.8 JRC 4558IC circuit diagram
Figure 3.1a The power supply circuit diagram
Figure 3.1b Block diagram of a power supply unit
Figure 3.2a The Pre-amplifier circuit diagram
Figure 3.2b The OP-amp audio mixer
Figure 3.3 The tone control circuit
Figure 3.4a A complementary symmetry class B amplifier
Figure 3.4b The output stage of the public address system
Figure 4.1 The circuit layout diagram
Figure 4.2 The body construction diagram (case)
Figure 4.6 Costing table.
TABLE OF CONTENTS
Title page
Dedication
Acknowledgement
Approval page
Abstract
List of tables, graph and figures
Table of contents
CHAPTER ONE
1.1 Introduction
CHAPTER TWO: DESCRIPTION OF CIRCUIT ELEMENT
2.1 Resistors
2.2 Capacitors
2.3 Diodes
2.4 Bipolar Junction Transistor (BJT)
2.5 Integrated Circuits (ICs)
CHAPTER THREE: PRINCIPLE OF OPERATION
3.1 Power supply
3.2 Pre-amplifier
3.3 Tone control
3.4 Power amplifier
CHAPTER FOUR: CONSTRUCTION AND TESTING
4.1 Breadboard/Prototyping
4.2 Circuit layout
4.3 Construction
4.4 Testing and Result
4.5 Packaging
4.6 Costing
CHAPTER FIVE: CONCLUSION/RECOMMENDATION
References
