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Design And Construction Of A TV Transmitter Circuit

Designing and constructing a TV transmitter circuit involves a meticulous process of selecting components, configuring circuits, and optimizing performance for efficient transmission of audiovisual signals. Key components include a modulator to convert the baseband signal into a modulated signal suitable for transmission, such as amplitude modulation (AM) or frequency modulation (FM), and an oscillator to generate the carrier frequency. The circuit must also incorporate amplifiers to boost the signal strength and filters to remove unwanted noise and harmonics. Careful consideration of the transmitter’s frequency range, power output, and compatibility with broadcast standards is essential. Furthermore, ensuring compliance with regulatory requirements and standards is crucial for legal operation. By employing innovative design techniques and leveraging modern semiconductor technologies, engineers can develop robust and efficient TV transmitter circuits capable of delivering high-quality signals over extended distances, thereby facilitating seamless broadcasting experiences.

ABSTRACT

Television is considered as a device of delivering images and sounds. In this respect, television technology has reached to a “perfection”. Media art using television would rely on such a “perfect” technology and would be satisfied with merely providing the “contents” to such a delivering device. However, it would be not an art. Art cannot remain the modernist “division of labour” of means and contents. As long as art shares the origin with technology, art should intervene into the technology itself. The main aim of this work is to build a low cost television transmitter. This a device or set of devices used to convert a television video signal and the accompanying audio signal into a composite radio frequency signal for transmission from an antenna.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

1.0 INTRODUCTION

1.1 AIM ANS OBJECTIVE OF THE PROJECT

1.2 PROBLEM STATEMENT

1.3 SCOPE OF THE STUDY

1.4 SIGNIFICANCE OF THE STUDY

1.5 APPLICATION OF THE PROJECT

1.6 LIMITATION OF THE PROJECT

1.8 DEFINITION OF TERMS

1.9 PROJECT ORGANISATION

CHAPTER TWO

2.0 LITERATURE REVIEW

2.1 TELEVISION TRANSMISSION AND RECEPTION

2.2 TRANSMISSION – GENERATING THE COLOUR PICTURE SIGNAL

2.3 THE TELEVISION CHANNEL

2.4 BROADCAST TELEVISION

CHAPTER THREE

3.0 METHODOLOGY

3.1 SYSTEM BLOCK DIAGRAM

3.2 BLOCK DESCRIPTION

3.3 SYSTEM CIRCUIT DIAGRAM

3.4 CIRCUIT COMPONENTS

3.5 TV TRANSMITTER CIRCUIT DESIGN

3.6 DESCRIPTION OF COMPONENTS USED

3.7 DESCRIPTION OF COMPONENTS USED

CHAPTER FOUR

RESULT ANALYSIS

4.0 CONSTRUCTION PROCEDURE AND TESTING

4.1 CASING AND PACKAGING

4.2 ASSEMBLING OF SECTIONS

4.3 TESTING OF SYSTEM OPERATION

4.4 HOW TO OPERATE THE SYSTEM

CHAPTER FIVE

5.0 CONCLUSION

5.1 RECOMMENDATION

5.2 REFERENCES

CHAPTER ONE

1.0 INTRODUCTION

1.1 BACKGROUND OF THE STUDY

A television transmitter is a transmitter that is used for terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, along with a synchronized audio channel, which is received by television receivers (‘televisions’ or ‘TVs’) belonging to a public audience, which display the image on a screen. A television transmitter, together with the broadcast studio which originates the content, is called a television station. Television transmitters must be licensed by governments, and are restricted to a certain frequency channel and power level. They transmit on frequency channels in the VHF and UHF bands. Since radio waves of these frequencies travel by line of sight, they are limited by the horizon to reception distances of 40–60 miles depending on the height of transmitter station.

Television transmitters use one of two different technologies: analog, in which the picture and sound are transmitted by analog signals modulated onto the radio carrier wave, and digital in which the picture and sound are transmitted by digital signals. The original television technology, analog television, began to be replaced in a transition beginning in 2006 in many countries with digital television (DTV) systems. These transmit pictures in a new format called HDTV (high definition television) which has higher resolution and a wider screen aspect ratio than analog. DTV makes more efficient use of scarce radio spectrum bandwidth, as several DTV channels can be transmitted in the same bandwidth as a single analog channel. In both analog and digital television, different countries use several incompatible modulation standards to add the video and audio signals to the radio carrier wave.

The principles of primarily analog systems are summarized as they are typically more complex than digital transmitters due to the multiplexing of VSB and FM modulation states.

1.2 STATEMENT OF THE PROBLEM

A rapidly growing demand for the use of television transmitter exists among individuals and institutions. For example universities and other tertiary institutions need to broadcast educational, entertainment and even news programme that are particularly designed for campus audience. Commercial television transmitter attempting to satisfy this need in Nigeria institutions. Private individual also wish to provide a view of local and community news that is independent government stand. These plants are however complex equipment demanding high power supply, high voltage system design, critical maintenance and exorbitant price. Farlex (2015) stated that transmitters of large powers require large current flow with high voltage up to 20kiv and transmitting plants are exposed to increased over voltage risk due to the usually exposed tower. Walter (2017) complained that the power supply and high voltage system design are probably the major problems for any new transmitter type.

These problems of the transmitter constitute major impediments to individual and institution that may wish to adopt television broadcast as means of electronic media. The private individual and organizations lack resources to purchase and maintain complex transmitting plant whose price is exorbitant and requires critical maintenance. The solution to this dilemma is the design and construction of a television transmitter where power supply is derived from low voltage system which is inherently safe to handle. The present project is design to make use of 12VDC supply, yet produce the range as required for local broadcast. If effort is not made to produce an television transmitter that is cheap in price, simple in maintenance, efficient in use and yet operate on low power, individual and private organization may not achieve their desire in radio broadcast.

1.3 AIM AND OBJECTIVES OF THE STUDY

This study is aimed at building a television transmitter. The following were the objectives developed for this particular project study:

To design and construct of television transmitter circuits which works over FM frequency
To transfer of video as well as audio signals over definite distance

To design of audio and video sender circuit by applying a voltage of 12V throughout the battery to circuit

1.4 SCOPE OF THE STUDY

The scope of this project work fusses on design and construction of television transmitter circuits. The circuit of TV transmitter is used for transmitting the audios along with the video signals. I analyzed the signals of the audio which are frequency modulated while there is PAL modulation of the video signals. I applied the modulated signals to the antenna. I had analyzed some of the applications of TV transmitter circuits such as it was used in the broadcasting applications, transmission of both audios as well as video signals.

1.4 SIGNIFICANCE OF THE PROJECT

This work will help mainly student involved in the design of television system so that embrace the required capabilities of the sense of vision of people. It will serve as a means of providing television services such as broadcast services into the television standards adopted. It will also help the student to know how to test the circuit and telecommunication equipment.

1.5 APPLICATION OF THE PROJECT

TV Transmitter Circuit has the following Applications

This is used in broadcasting applications.
This circuit can transmit audio and video signals from DVD, videogames, etc.
The circuit can be used in surveillance cameras.

1.6 LIMITATIONS OF THE CIRCUIT

The transmitter circuit is compatible with PALB and PALG systems.
To get optimum performance, one should adjust the value of C8.

1.7 DEFINITION OF TERMS

Direct Current (DC): The unidirectional flow of electric charge produced by sources such as batteries and solar cells.

Frequency Modulation (FM): A method of radio modulation in which the frequency of the carrier wave are varied. FM frequency range is 88 to 108 MHz

Hertz (Hz): Unit of frequency in the International System of Units (SI) defined as 1 cycle per second, named for Heinrich Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves.

Modulation: In electronics and telecommunications, the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted. The information may take the form of audio or data.

Radio Frequency (RF): A rate of oscillation that corresponds to the frequency of radio waves and the alternating currents that carry radio signals.

Oscillator: device that generates a frequency

1.8 PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work, chapter two presents the literature review of the study, chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.