Construction of Power Supply with Positive and Negative Output Voltage and Variable Current Output

Construction of Power Supply with Positive and Negative Output Voltage and Variable Current Output

CHAPTER ONE

1.0 INTRODUCTION

A power supply is an electronic device that converts A.C to a lower regulated D.C output. The primary function of a power supply is to convert electric current form a source to the correct current, voltage and frequency to power the load. The beauty of this power supply is that it has various current and voltage outputs that can work at the same time. Hence, it is known as a multiple power supply.

The project is a low cost power supply that has double positive and negative output voltages with various values of current: 1A, 2A and 3A. The project uses a step down transformer connected in parallel with each other in other to produce more current values. The major part of the circuit that does the rectification is the bridge rectifier.

It converts the A.C to D.C form therefore other things such as electrolytic and ceramic capacitors used to be connected to the circuit to make the D.C output pure.

The D.C power supply is a modular power supply used as power source to electronic equipment and industrial instrumentation, it can also be used as a power pack. The regulated power supply provides short circuit protection/over voltage potential in addition to maintain load voltage regulation. The power supply is termed as fixed voltage power supply because the voltage present does not vary.

1.1 AIM OF THE PROJECT

The aim of the project is to construct a power supply that is able to charge various electrical devices within 5 and 12volts with current value of 1-3amps.

1.2 OBJECTIVE OF THE PROJECT

The objective of this project is to develop a power conversion system suitable to produce a multipurpose D.C. power supply.

1.3 SCOPE OF THE PROJECT

There are several scope that can be propose for the project:

This project is focus on A.C. to D.C. converter

The D.C. power supply circuit is able to convert the fix voltage of 220/240Vac to desire D.C. volts within 0 to 24V.

1.4 RELEVANCE OF THE PROJECT

This project is to convert high voltage A.C. to low voltage D.C. in order to power electrical devices of low current values, e.g. computers, phones.

1.5 LIMITATIONS OF THE PROJECT

It is not able to power above 12V electrical devices.

It is not able to supply current above 3amps.