Design And Construction Of A Transformerless Power Supply

ABSTRACT

Tranformer less power supply is an electronic device that supplies electric energy to an electrical load without a transformer for stepping up or down. The primary function of a power supply is to convert one form of electrical energy to another. This is done by use a reactance to limit the current, rectify the voltage with a diode, regulate the voltage with a zener, and use a large electrolytic capacitor to filter out the ripples.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• AIM OF THE PROJECT
• APPLICATION OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• LIMITATION OF THE PROJECT
• PROJECT WORK ORGANIZATION

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF POWER SUPPLY
• REVIEW OF GENERAL APPLICATION OF POWER SUPPLY APPLICATIONS
• REVIEW OF OTHER TYPES OF POWER SUPPLY
• CATEGORY OF POWER SUPPLY
• REVIEW OF POWER SUPPLY PACKAGING

CHAPTER THREE

SYSTEM DESIGN

• SYSTEM BLOCK DIAGRAM
• SYSTEM CIRCUIT DIAGRAM
• CIRCUIT EXPLANATION
• CONSTRUCTION NOTES
• DESCRIPTION OF COMPONENTS USED

CHAPTER FOUR

4.0   TESTING AND RESULTS

• CONSTRUCTION PROCEDURE
• CASING AND PACKAGING
• ASSEMBLING OF SECTIONS
• PACKAGING
• TESTING OF SYSTEM OPERATION
• INSTALLATION OF THE COMPLETED DESIGN
• COST ANALYSIS
• OBSERVATIONS

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

 CHAPTER ONE

1.0                                                        INTRODUCTION

A power supply is an electronic device that supplies electric energy to an electrical load. The primary function of a power supply is to convert one form of electrical energy to another and, as a result, power supplies are sometimes referred to as electric power converters. Some power supplies are discrete, stand-alone devices, whereas others are built into larger devices along with their loads. Examples of the latter include power supplies found in desktop computers and consumer electronics devices.

Every power supply must obtain the energy it supplies to its load, as well as any energy it consumes while performing that task, from an energy source. Depending on its design, a power supply may obtain energy from various types of energy sources, including electrical energy transmission systems, energy storage devices such as a batteries and fuel cells, electromechanical systems such as generators and alternators, solar power converters, or another power supply.

All power supplies have a power input, which receives energy from the energy source, and a power output that delivers energy to the load. In most power supplies the power input and output consist of electrical connectors or hardwired circuit connections, though some power supplies employ wireless energy transfer in lieu of galvanic connections for the power input or output. Some power supplies have other types of inputs and outputs as well, for functions such as external monitoring and control. It’s often necessary to power a low voltage circuit such as a microcontroller with HV AC line current. For example, most fire alarms are powered this way. In these situations, a transformer is both bulky and expensive especially if the device is a consumer product. The solution is to use a reactance to limit the current, rectify the voltage with a diode, regulate the voltage with a zener, and use a large electrolytic capacitor to filter out the ripples.

1.2                                           AIM OF THE PROJECT

The aim of this work is to provide the required DC power to the load using an AC supply at the input without using transformer. Different applications require different attributes, but more often than not these days DC power supplies provide an accurate output voltage – this is regulated using electronic circuitry (such as zener diode) so that it provides a constant output voltage over a wide range of output loads.

1.3                               APPLICATION OF THE PROJECT

This device is used in powering of electronics appliances such as radio, DVD.

1. It is used in cellphone charger
2. It is used in Solar energy system

• It is used in vehicles

1.4                              SIGNIFICANCE OF THE PROJECT

The output voltages can be use to achieve different voltage level by varying the value of the zener diode.

1. Its cost is lesser than transformer power supply
2. it is more portable than transformer power supply

1.5                              LIMITATION OF THE PROJECT

The main limitation of transformer-less power supplies is that they don’t offer isolation from the HV line and present more of a safety issue.

1.6                              PROJECT WORK ORGANIZATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to a transformer less power supply. In this chapter, the background, significance, objective limitation and problem of a transformer less power supply were discussed.

Chapter two is on literature review of a transformer less power supply. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.