This project work deals on the design and construction of an Rf based remote control for an electronic/electrical device say electric lamp with the aim of switching on/off of the lamp at discretion and from a distance. It also eliminates the inconveniences associated with manual switching of lamps. This electronic system is designed in two functional units; the transmitter and the receiver using radio frequency (RF) communication wave band. The transmitter is a hand-held remote control while the receiver consists of a tuned radio frequency receiver, clock generator, delay circuit, flip-flop and a driver circuitry and electromagnetic relay which actuates the load (lamp). When the remote control button is pressed, the lamp comes ON and remains ON until the remote is pressed again – it goes OFF. Many advantages are accredited to this design in terms of robust, durability, cost effectiveness and components availability. The result being the simple design of a system easy to operate and maintain. A miniaturized design of it will be a reliable, robust and rugged consumer electronics that will sell like a German burger.

TABLE OF CONTENTS

Title Page - - - - - - - i

Certification Page - - - - - - - ii

Approval Page - - - - - - - iii

Dedication - - - - - - - iv

Acknowledgement - - - - - - v

Abstract - - - - - - - - vi

Table of Contents - - - - - - - vii

CHAPTER ONE

1.1 Introduction - - - - - - 1

1.2 General Description of the Project - - - 1

1.3 Objectives of the Project - - - - - 2

1.4 Significance of the Project - - - - 3

1.5 Scope of the Project - - - - - 3

1.6 Project Report Layout - - - - - 4

CHAPTER TWO: LITERATURE REVIEW

2.1 The Historical Background of the Project- - 5

2.2 Applications of the Project - - - - 7

2.3 Theories and Models Relevant to the Design - 7

2.3.1 Electromagnetic Spectrum. - - - - 7

2.3.2 Radio Frequency Wave Band - - - 12

2.3.3 Tuned Class – C Amplifiers - - - 15

2.3.4 Transistors and Electromagnetic Relays - 16

2.3.5 Flip-Flops and Delay Circuits - - - 21

2.4 Other System Components - - - - 23

2.4.1Resistors - - - - - - - 23

2.4.2Capacitors - - - - - - - 26

2.4.3Junction Diodes - - - - - - 29

2.4.4Linear Voltage Regulators - - - - 39

2.4.5Voltage Regulator 78xx - - - - - 32

Chapter Three: Methodology and System Analysis

3.1 Methodology - - - - - - - 35

3.1.1Top Down - - - - - - - 35

3.1.2Bottom up - - - - - - - 37

3.1.3Prototyping - - - - - - 37

3.1.4Choice of Design Approach - - - - 39

3.2 Analysis of Existing System - - - - 39

3.2.1Information Gathering - - - - 40

3.2.2Data Analysis - - - - - - 41

3.2.3Limitations of the Exiting System - - - 41

Chapter Four: System Analysis and Design

4.1 Description of the System Building Blocks - 42

4.2 Block Diagram Development into Working Circuit,

System Design Specification and Power Supply Unit. 44

4.2.1Block Diagram Development into Working Circuit 44

4.2.2System Design Specification - - - - 45

4.2.3Power Supply Unit - - - - - 46

4.3 Description of the System Operation - - 48

4.4 System Design Calculation - - - - 51

4.4.1. Power Supply Unit - - - - 51

4.4.2 Modulated Frequency Generator - - 52

4.4.3 Modulator Circuit - - - - 53

4.4.4 Carrier Generator - - - - 53

4.5 Complete Circuit Diagram of the System - - 51

Chapter Five: implementation, Testing and Results

5.1 System Implementation - - - - 59

5.2 System Testing - - - - - - 59

5.3 Results - - - - - - - 60

5.4 Packaging - - - - - - - 61

5.5 Limitation - - - - - - - 61

5.6 Billing of Engineering Quantity - - - 62

Chapter Six: Summary and Conclusion

6.1 Summary - - - - - - - 64

6.2 Problems Encountered - - - - 65

6.3 Recommendation - - - - - 65

6.4 Conclusion - - - - - - 67

Reference - - - - - - - 69

User’s Guide - - - - - - 70

CHAPTER ONE

1.1 INTRODUCTION

Electronic communication has gained a holistic approach in the world technological growth. Apparently, no modern electronic system is capable of fascinating the society without an aspect of telecommunication. This trend is so progressive that most remote control systems are designed with RF.

1.2 GENERAL DESCRIPTION OF THE PROJECT

The above-mentioned development motivated me to embark on a project research work on the design and construction of an Rf based remote control electric lamp. This electronic system is designed with a handheld remote control realized using frequency generator and modulator coupled into a tuned class-C amplifier. The amplified signal is radiated into the atmosphere through a tank circuit at a particular frequency. The receiver is realized with a tuned radio frequency (TRF) receiver coupled into a transistor static switch. These solid state switches are used to clock a D-type flip-flop through a delay circuit. The output of the flip-flop biases a driver circuitry realized using a Darlington pair transistors which drives the relay to switch ON/OFF the lamp connected to its normally open contact, whenever the remote is pressed.

1.3 OBJECTIVES OF THE STUDY/PROJECT

One of the objectives of this project is to design and implement an Rf based remote control for electric lamp capable of switching ON/OFF of electric lamp from a maximum distance of 200m at convenience.

It is also aimed at exposing the graduating student to electronic system design using random logic. It is also aimed at familiarizing the young engineers with digital system design involving telecommunication systems. Another objective of this project is to ground the young engineers in engineering design which is indispensable in engineering professional practice.

1.4 SIGNIFICANCE OF THE PROJECT

This project work signifies a lot in telecom, computer and electronic engineering. It is very useful in a number of domestic places like in bedroom and security lamps in the compound. A project of this type if modified can be used as a gate/door opening system, car immobilizer and for industrial process control. Another vital significance of this system is in the control of Air conditioner and refrigerators and other lamps in modern buildings. This system can be used to start and stop a power generating set from a distance.

1.5 SCOPE OF THE PROJECT

This project work covers the following: tuned radio frequency transmitter and receiver, flip-flops, Darlington pair transistors and delay circuits. It also lays great emphasis on passive and active components used to implement the system. It x-rays the mode of calculation of the basic circuit parameters and other areas of application of the system.

1.6 PROJECT REPORT ORGANIZATION

This project is presented in six chapters to appropriately illustrate the steps involved in its implementation. Chapter one introduce the design overview, objective and significance of the project. Chapter two is basically the literature review and some theories relevant to the design. Chapter three x-rays the methodology and analysis. Chapter four is on the system design analysis while chapter five elaborates on the implementation, testing and results. Finally chapter six summarizes the entire thesis and recommendations.