Design And Construction Of A Transformerless Power Supply

Electrical Electronics Engineering

The design and construction of a transformerless power supply involves the creation of a circuit capable of converting AC voltage from the mains into a stable DC output without the use of a traditional transformer. This endeavor typically requires the utilization of components such as capacitors, resistors, diodes, and voltage regulation circuitry to step down, rectify, and regulate the voltage safely and efficiently. Transformerless power supplies offer advantages in terms of reduced size, weight, and cost compared to transformer-based counterparts, making them suitable for applications where space and economy are paramount. However, they also pose unique challenges such as limited isolation between input and output, necessitating careful consideration of safety measures and insulation. Furthermore, ensuring compliance with regulatory standards and mitigating common issues like electromagnetic interference (EMI) and voltage fluctuations are crucial aspects of the design process. By implementing appropriate circuit topology, component selection, and protective measures, transformerless power supplies can provide reliable and efficient power delivery for various electronic devices and systems, catering to the demands of modern technology while enhancing energy efficiency and reducing environmental impact.

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.

It is used in cellphone charger
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.

Its cost is lesser than transformer power supply
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.