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.
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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, phones1.5
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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.
