DESIGN AND CONSTRUCTION OF A WIRELESS LOUDSPEAKER
ABSTRACT
Wireless the speaker is a type of speaker that transmits audio signals using radio frequency (RF) waves rather than over audio cables. As things stand today, the term ‘wireless’ in the audio and video world does not mean wireless rather all it means is fewer wires. A common complaint against home audio systems has been the cables that interconnect the speakers to the audio receiver, tuner, CD player, or stereo units. As more and more channels are added to modern audio equipment, the problem of connecting the speakers to the audio sources is getting worst.
In this project, a wireless loudspeaker that will transmit using radio frequency (RF) is designed and constructed. The receiver and the transmitter circuits were implemented to achieve the aim of this project.
The the method used involves the design of the receiver and the transmitter circuits as well as the amplifier and the nature of the mixer. The transmitter was designed to use a 9V battery which can easily be replaced. The radius of reception is within 100meters with a power output of 0.03MW. The amplifier was designed to produce an output power of 20W to an 8ohms (8 ) loudspeaker. The audio amplifier was powered from the rectified 220Vac.supply.The receiver consists of an aerial and a demodulator with the help of a tuned circuit which helps to pick the required signal.
The components were initially mounted on a breadboard and tested; some of the mistakes were corrected before finally transferring it onto the printed circuit board (PCB) for permanent soldering. The whole circuit was successfully tested, and it was observed that the system is functioning in optimal condition. Due to this fact, one can rate the project’s performance at about 87%.
The the constructed wireless loudspeaker system can stand the test of time in its performance. It is very reliable, and the overall performance is excellent. Conclusively the wireless loudspeaker system successfully achieved the aim of transmitting and receiving voice signals over a distance. I learned and researched more on the use of modulation and demodulation, the amplifier circuitry, etc.
TABLE OF CONTENTS
Title page i
Certification ii
Dedication iii
Acknowledgment iv
Table of contents v
List of figures ix
List of tables x
List of abbreviations xi
Abstract xii
CHAPTER ONE
1.0 INTRODUCTION 1
1.1 Preambles 1
1.2 System block diagram 3
1.3 Background study 5
1.4 Aims and objectives 7
1.5 Problem statement 7
1.6 Justification 7
1.7 Scope of study 9
CHAPTER TWO
2.0 LITERATURE REVIEW 10
2.1 Ancient medium of information transmission 10
2.2 Modern-day medium approach 11
2.2.1 Problems associated with the earlier system 11
2.2.2 Working principles of the modern system 12
2.3 Wireless transmission system 12
2.3.1 Wired transmission system 13
2.4 Public transmission system 13
2.4.1 The transmitter system 13
2.4.2 The receiver system 15
2.4.3 Antenna 15
2.4.3.1 Channel 16
2.4.3.2 Functions of the antenna 16
2.4.4 The tone control and the mixing stage 16
2.4.5 The audio amplifier 17
2.4.6 The loudspeaker 17
2.5 Modulation 18
2.5.1 Frequency modulation 18
CHAPTER THREE
3.0 METHODOLOGY 21
3.1 Power supply unit design 21
3.2 Transmitter design 22
3.3 Amplifier circuit design 24
3.4 Receiver principles 26
3.5 Demodulation 26
3.6 The input stage 27
3.7 Transmitter circuitry 27
3.8 Mixing stage 27
3.9 Audio power amplifier 31
CHAPTER FOUR
4.0 CONSTRUCTION AND TESTING 32
4.1 The power supply 32
4.2 The output power amplifier 32
4.3 Dissipation of excess heat &
.