Design And Construction Of A USB Powered 30W Audio Amplifier

ABSTRACT

This work is titled the design and construction of a USB powered 30Watt Amplifier. An audio Amplifier is a device for increasing the audio power of a signal by use of an external energy source. It is design to meet up with the amplification demand in homes, offices, industries and especially in music industries. An audio Amplifier low-power audio signals (signals composed primarily of frequencies between 20 – 20 000 Hz, the human range of hearing) to a level suitable for driving loudspeakers and is the final stage in a typical audio playback chain, While the input signal to an audio amplifier may measure only a few hundred microwatts, its output may be tens, hundreds, or thousands of watts.

This device is designed to be powered with 5v dc source from pc to deliver appreciable 30Watt power to the load.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• PROBLEM STATEMENT
• AIM / OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• SCOPE OF THE PROJECT
• APPLICATION OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• HISTORITICAL BACKGROUND OF AN AMPLIFIER
• REVIEW OF CLASSIFICATION OF POWER AMPLIFIERS
• CLASSIFICATION ACCORDING TO MODE OF OPERATION
• OVERVIEW UNIVERSAL SERIAL BUS (USB)

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1      SYSTEM BLOCK DIAGRAM

3.2     SYSTEM CIRCUIT DIAGRAM

3.3      SYSTEM DESCRIPTION

3.4      DESCRIPTION OF COMPONENT USED

CHAPTER FOUR

4.0      CONSTRUCTION PROCEDURE AND TESTING

4.1      CASING AND PACKAGING

4.2      ASSEMBLING OF SECTIONS

4.3      TESTING OF SYSTEM OPERATION

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

An audio amplifier is an electronic amplifier that amplifies low-power audio signals to a level suitable for driving loudspeakers. It is the final electronic stage in a typical audio playback chain.

This amplifier is a small signal amplifier that delivers an appreciable power to the load, and as we know from above, is the product of the voltage and current applied to the load with the output signal power being greater than the input signal power. In other words, a power amplifier amplifies the power of the input signal which is why these types of amplifier circuits are used in audio amplifier output stages to drive loudspeakers.

This power amplifier works on the basic principle of converting the DC power drawn from the laptop computer into an AC voltage signal delivered to the load. Although the amplification is high the efficiency of the conversion from the DC power supply input to the AC voltage signal output is usually poor.

1.2                                        AIM/OBJECTIVE OF THE PROJECT

The main objective of this work is to build an audio power amplifier that will receives power sources from a Laptop usb port.

At the end of this work, the student involved shall be able to

1. Construct this device with power rating of 30w.
2. Understand how to use and connect USB in the system.

1.3                                         APPLICATION OF THE PROJECT

Important applications of this device include:

1. little public address systems
2. for amplifying computer audio signal

• for amplifying of our home potable audio devices for entertainment such as “world receiver” radio

1.4                                              PURPOSE OF THE PROJECT

The main purpose of this work is to build a small signal, low-voltage power supply, compatibility with USB power amplifier.

1.5                                         SIGNIFICANCE OF THE PROJECT

Today there are many categories of amplifiers used for multifarious purposes. In simple terms an amplifier picks up a weak signal and converts it into a strong one. It is widely used in several devices to boost electrical signals such Radios, televisions computer and telephones. This circuit of multimedia speakers for PCs has single-chip-based design, low-voltage power supply, compatibility with USB power, easy heat-sinking, low cost, high flexibility and wide temperature tolerance.

1.6                                           LIMITATION OF THE PROJECT

1. Noise: This device tends to add some random noise to the signals passing through them, hence degrading the SNR (signal to noise ratio). This, in turn, limits the accuracy of any measurement.
2. Limited output voltage, current, and power levels. This amplifier cannot output signals above 30w.
3. it is powered by 5v supply from the laptop computer usb port
4. audio signal is sent to the amplifier using rf plug

1.7                                                         PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work, chapter two presents the background for USB powered audio amplifier, chapter three describes the methods applied, chapter four discusses the test and results, chapter five concludes the research outcomes and the recommendations.