final year project topics and materials

ABSTRACT

Uninterruptible power supplies (UPS) are used to provide power when regular utility power is unavailable.  Although they are commonly used for providing power in remote locations or emergencies, this is not because they are the same as auxiliary power units, emergency power units or standby generators.

Unlike the aforementioned power sources, UPS provides an immediate and continuous supply of power to a device, hence protecting it from power interruption and allowing time for auxiliary or emergency powers, to kick in equipment to be safely shut down or utility power restored.

The major aim of this was to design a system which will be able to convert battery voltage(12v) to 220v, which is equivalent to wall outlet and secondly able to charge the battery.

The chapter one of this work, gives the over-view of UPS, it’s importance, uses, and application and some of its special features like its ability to correct frequency instability and many more.

Secondly, this work dealt with all components used in the construction of the device, there working condition and uses. Some basic abstract phenomenon were also treated like wave forms and electronic switching.

The chapter three, basically dealt on all electrical measuring instrument used in and on the device, how they are used, why and where.

The fourth chapter explains how the components where assembled into section and the sectional connection used to form the device.

The last chapter is a simple conclusion with honest recommendation.

TABLE OF CONTENT

CERTIFICATION         -        -        -        -        -        -        -        -        i

DEDICATION     -        -        -        -        -        -        -        -        ii

ACKNOWLEDGEMENT       -        -        -        -        -        -        iii

ABSTRACT        -        -        -        -        -        -        -        -        iv

TABLE OF CONTENT          -        -        -        -        -        -        -        v

CHAPTER ONE

1.1     INTRODUCTION         -        -        -        -        -        -        1

1.1     AIMS AND OBJECTIVES     -        -        -        -        -        8

1.2     SCOPE OF THIS PROJECT   -        -        -        -        -        8

1.3     AVAILABILITY OF DESIGN MATERIALS      -        -        8

CHAPTER TWO

2.1     LITERATURE REVIEW        -        -        -        -        -        9

2.1     WHAT IS A UPS?         -        -        -        -        -        -        -        9

2.2     WAVEFORMS    -        -        -        -        -        -        -        9

2.2.1 SQUAREWAVE  -        -        -        -        -        -        -        9

2.2.2 MODIFIED SINE WAVE        -        -        -        -        -        10

2.2.4 TRUE SNE WAVE        -        -        -        -        -        -        -        10

2.3     RESISTORS        -        -        -        -        -        -        -        11

2.4     CAPACITORS     -        -        -        -        -        -        -        12

1.4.1 CAPACITANCE  -        -        -        -        -        -        -        13

2.4.2 ELECTROLYTIC CAPACITOR       -        -        -        -        14

2.4.3  PLASTIC FILM, CERAMIC NAD MONOLITHIC

CAPACTOR -      -        -        -        -        -        -        -        14

2.5     DIODE       -        -        -        -        -        -        -        -        16     

2.5.1 MOUNTING A DIODE -        -        -        -        -        -        18

2.5.2 CHARACTERISTICS CURVES OF A DIODE   -        -        18

2.5.3 IDEAL DIODE     -        -        -        -        -        -        -        19

2.5.4 LIGHT EMITTING DIODE     -        -        -        -        -        19

2.5.5 DIODES AS RECTIFIERS      -        -        -        -        -        21

2.5.5.1 HALF-WAVE RECTIFIER  -        -        -        -        -        22

2.5.5.2  FULL-WAVE, CENTER-TAP RECTIFIE       -        -        23

2.5.6    FILTERS  -        -        -        -        -        -        -        -        24

2.6     TRANSISTORS   -        -        -        -        -        -        -        26

2.6.1 TRANSISTOR AS A SWIRCH        -        -        -        -        -        26

2.6.2 MOSFETS  -        -        -        -        -        -        -        -        28     

2.6.2.1 SUPER-HIGH INPUT IMPEDANCE -    -        -        -        29

2.6.2.2. SETBACKS IN MOSFETS -        -        -        -        -        29

2.6.2.3 ITS FLEXIBILITY      -        -        -        -        -        -        30

2.7      OPTO-COUPLER        -                  -        -        -        -        -        30

2.7.1  OPTO-COUPLER CHARACTERISTICS -         -        -        -        31

2.7.2  ITS INPUT -        -        -        -        -        -        -        -        32

2.7.3 ITS OUTPUT       -        -        -        -        -        -        -        32

2.7.4  ITS OPERATING MODE      -        -        -        -        -        33

2.8     THE SG3524 INTEGRATED CIRCUIT   -        -        -        33

2.8.1  OPERATING PRINCIPLE OF SG3524    -        -        -        34

CHAPTER THREE    

3.0     METHODOLOGY        -        -        -        -        -        -        36

3.1     ELECTRONIC WORKBENCH        -        -        -        -        37

3.2     GALVANOMETER      -        -        -        -        -        -        37

3.3     OSCILLOSCOPE -        -        -        -        -        -        -        38

3.4     VOLTMETER     -        -        -        -        -        -        -        39

3.5     AMPMETER       -        -        -        -        -        -        -        41

3.6     WATTMETER    -        -        -        -        -        -        -        43

3.7     MULTIMETERS -        -        -        -        -        -        -        44

CHAPTER FOUR

4.0     DESIGN AND CONSTRUCTION METHODS  -        -        46

4.1     COMPLETE CIRCUIT DIAGRAM OF A UPS   -        -        47

4.2     STAGE BY STAGE DESIGN          -        -        -        -        -        47

4.2.1  OSCILLATOR SECTION      -        -        -        -        -        50

4.2.2  DRIVER/SWITCHING SECTION   -        -        -        -        51

4.2.3  THE OUTPUT SECTION      -        -        -        -        -        52

4.2.4  THE CHANGEOVER SECTION    -        -        -        -        53

4.2.5  THE LOW BATTERY CUT-OFF SECTION      -        -        54     

4.3     COMPONENT JUSTIFICATION    -        -        -        -        55

4.3.1  MOSFETS -        -        -        -        -        -        -        -        55

4.3.2 SG3524 OSCILLATOR -        -        -        -        -        -        55

4.3.3 OPTO-COUPLER -        -        -        -        -        -        -        56

4.3.4 RESISTORS         -        -        -        -        -        -        -        -        56

4.4 TEST AND ANALYSIS   -        -        -        -        -        -        56

4.4.1  TESTING AND SETTING THE INVERTER    -        -        57

4.5     BILL OF ENGINEERING CONSTRUCTION    -        -        60

CHAPTER FIVE

5.0 CONCLUSION        -        -        -        -        -        -        -        62

5.1 RECOMMENDATION     -        -        -        -        -        -        62

 REFERENCES   -        -        -        -        -        -        -        63

LIST OF FIGURES

Fig 1.                   Offline/ standby diagram      -        -        -        5

Fig 2.                   A capacitor         -        -        -        -        -        12

Fig 3.                   Capacitors -        -        -        -        -        -        15

Fig 4.                   Circuit Symbol of a diode -   -        -        -        17

Fig 5.                   A Led         -        -        -        -        -        -        20

Fig 6.                   Half-wave rectifier       -        -        -        -        21

Fig 7.                   Half wave Rectifier      -        -        -        -        22

Fig 8.                   A full-wave centre tap rectifier       -        -        24

Fig 9.                   A Simple filter     -        -        -        -        -        25

Fig 10.       Transistor as a Switch -        -        -        -        27

Fig 11.       A Transistor as a Switch      -        -        -        27

Fig 12.       A Mosfet    -        -        -        -        -        -        28

Fig 13        Opto-Coupler’s Input   -        -        -        -        32

Fig 14.       Inputs and output circuit of an opto-coupler - 32

Fig 15.       A Digram of a Voltmeter       -        -        -        41

Fig 16.       Diagram of Amp meter         -        -        -        -        42

Fig 17        Diagram of a Wattmeter arrangement   -        43

Fig 18        Oscillator Circuit           -        -        -        -        -        49

Fig 19        Pre-Driver Section       -        -        -        -        51

Fig 20        Change over circuit of the UPS    -        -        53

Fig 21        Low battery cut-off circuit     -        -        -        54CHARACTERISTICS CURVES OF A DIODE   CITORS

l and may God reward you. , Sir CHristopher chukwu and family, Elder Emmanuel a

CHAPTER ONE

1.10 INTRODUCTION

As blackouts roll through power-starved communities, the threat to you and your computer is not the lack of electricity, but the change in power. When the lights are off and you are about to start any industrial or computer-based projects,  all your efforts will be wasted. Even when your system acts as a server, a sudden shutdown could disrupt the processing of many others. You can make your work immune to the intransigence of rolling blackouts and protect against many other types of unexpected power disturbances. Your secret weapon is the uninterruptible power supply or uninterruptible power source. Commonly called the UPS, this devices is a cleaver threefold package-a set of battery, an inverter that transforms the low-voltage direct current of the batteries into the standard alternating current equivalent to your wall outlet, and a battery changer that assures that reserve power storage system (the batteries) with interfaces to mach it to utility power and your computer system. A UPS differs from an auxiliary emergency power system or standby generator in that it will provide instantaneous or near-instantaneous protection from input power interruptions by means of one or more attached batteries and associated electronic circuitry for low power users, and or by means of diesel generators and flywheels for high power users. While not limited to protecting any particular type of equipment, a UPS is typically used to protect computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption and/or data loss. UPS units range in size from units designed to protect a single computer without a video monitor (around 200 VA rating) to large units powering entire data centers, buildings, or even cities. The UPS is designed to project against changes, specifically a temporary loss of electrical supply.