COMPUTER ENGINEERING PROJECT: DESIGN AND CONSTRUCTION OF AN UNINTERRUPTIBLE POWER SUPPLY FOR A PERSONAL COMPUTER

CONSTRUCTION OF AN UNINTERRUPTIBLE POWER SUPPLY FOR A PERSONAL COMPUTER

BY

SYLVESTER OSEGHALE

MATRIC NO: I.C.P/014/DO309

DEPARTMENT OF COMPUTER ENGINEERING TECHNOLOGY, FACULTY OF ENGINEERING

IKARE CITY POLYTECHNIC,

JULY. 2015.

CERTIFICATION

           

This Project construction of an ‘UNTERRUPTIBLE POWER SUPPLY’ (UPS) was completed under the supervision and found acceptable in partial fulfillment of the requirement for the award of National Diploma in Computer Engineering Technology Ikare City Polytechnic, Ondo State.

Certified by:

………………….                                                    ………………………

Engr.  Adams. O                                                                     Date

(Project supervisor)

ABSTRACT

Digital equipment such as computers, telecommunication systems and instruments use microprocessors that operate at high frequencies allowing them to carry out millions or even billions of operations per second. A disturbance in the electrical supply lasting just a few milliseconds can affect thousands or millions of basic operations. The result may be malfunctioning and loss of data with dangerous or costly consequences (e.g. loss of production). That is why many loads, called sensitive or critical loads, require a supply that is protected. Many manufacturers of sensitive equipment specify very strict tolerances, much stricter than those in the distribution system for the supply of their equipment, one example being Computer Business Equipment Manufacturer’s Association for computer equipment against distribution system disturbances. The design of this uninterrupted power supply (UPS) for personal computer (PC) is necessitated due to a need for enhanced portability in the design of personal computer desktop workstations. Apart from its original functionality as a backup source of power, this design incorporates the unit within the system unit casing, thereby reducing the number of system components available. Also, the embedding of this unit removes the untidiness of connecting wires and makes the whole computer act like a laptop. Not to be left out is the choice of a microcontroller as an important part of the circuitry. This has eliminated the weight and space-consuming components that make up an original design. The singular use of this microcontroller places the UPS under the class of an advanced technology device.

                                  DEDICATION

This work is dedicated to God almighty, my beloved parents, Rev & Dr. Mrs.  P.E Oseghale.  Without their help I wouldn’t realized this work.

ACKNOWLEDGEMENT

I wish to thank Almighty God who in his infinite mercy, granted me the strength to do and complete this work. Secondly, to my lecturers, My project supervisor Engr. Adams, My friends and many others.

Once again am particularly grateful to my parents for their encouragement till this stage of my life. However, am indebted to all the staff and teachers of faculty of Engineering, Ikare City Polytechnic. My brother Joshua, my sisters Oseremen, Osesonaga and Wuraola should also be thanked for their supports and encouragement.

Finally I wish to thank all my departmental staff for their help.

TABLE OF CONTENT

ABSTRACT        -        -        -        -        -        -        -        i

DEDICATION -   -        -        -        -        -        -        -        iii

ACKNOWLEDGEMENT       -        -        -        -        -        iv

TABLE OF CONTENT          -        -        -        -        -        -        v

TABLE OF FIGURES-  -        -        -        -        -        -        x

CHAPTER ONE

1.1     INTRODUCTION         -        -        -        -        -        1

1.1     AIMS AND OBJECTIVES     -        -        -        -        7

1.2     SCOPE OF THIS PROJECT   -        -        -        -        7

1.3     AVAILABILITY OF DESIGN MATERIALS      -        7

CHAPTER TWO

2.1     LITERATURE REVIEW        -        -        -        -        8

2.1     WHAT IS A UPS?         -        -        -        -        -        -        8

2.2     WAVEFORMS    -        -        -        -        -        -        8

2.2.1 SQUAREWAVE  -        -        -        -        -        -        8

2.2.2 MODIFIED SINE WAVE        -        -        -        -        9

2.2.4 TRUE SNE WAVE        -        -        -        -        -        -        9

2.3     RESISTORS        -        -        -        -        -        -        10

2.4     CAPACITORS     -        -        -        -        -        -        11

1.4.1 CAPACITANCE  -        -        -        -        -        -        12

2.4.2 ELECTROLYTIC CAPACITOR       --       -        -        13

2.4.3  PLASTIC FILM, CERAMIC NAD MONOLITHIC

CAPACTOR -      -        -        -        -        -        -        14

2.5     DIODE       -        -        -        -        -        -        -        15     

2.5.1 MOUNTING A DIODE -        -        -        -        -        16

2.5.2 CHARACTERISTICS CURVES OF A DIODE   -        17

2.5.3 IDEAL DIODE     -        -        -        -        -        -        17

2.5.4 LIGHT EMITTING DIODE     -        -        -        -        18

2.5.5 DIODES AS RECTIFIERS      -        -        -        -        19

2.5.5.1 HALF-WAVE RECTIFIER  -        -        -        -        20

2.5.5.2  FULL-WAVE, CENTER-TAP RECTIFIE       -        21

2.5.6    FILTERS  -        -        -        -        -        -        -        22

2.6     TRANSISTORS   -        -        -        -        -        -        23

2.6.1 TRANSISTOR AS A SWIRCH        -        -        -        -        23

2.6.2 MOSFETS  -        -        -        -        -        -        -        25     

2.6.2.1 SUPER-HIGH INPUT IMPEDANCE -    -        -        25

2.6.2.2. SETBACKS IN MOSFETS -        -        -        -        26

2.6.2.3 ITS FLEXIBILITY      -        -        -        -        -        26

2.7      OPTO-COUPLER        -        -        -        -        -        -        27

2.7.1  OPTO-COUPLER CHARACTERISTICS -         -        -        28

2.7.2  ITS INPUT -        -        -        -        -        -        -        28

2.7.3 ITS OUTPUT       -        -        -        -        -        -        28

2.7.4  ITS OPERATING MODE      --       -        -        -        29

2.8     THE SG3524 INTEGRATED CIRCUIT   -        -        29

2.8.1  OPERATING PRINCIPLE OF SG3524    -        -        30

FULL PROJECT