Description
 INTRODUCTION
The idea behind a UPS (Uninterruptible Power Supply) is pretty obvious from the name, in addition to filtering, enhancing or modifying the unity power, special circuit and batteries are used to prevent electrical machines from losing power during a disruption (blackout or voltage sag brownout). The units are all called different names depending on the next design, but all fit into general category of backup power.
Before delving into details of how an uninterruptible power supply works, let’s take a quick look of the basic of the type of equipment. An electrical device plugged into the wall or into a surge suppressor has only one source of power. If there is a blackout, the electricity is out an the device obviously goes off immediately. A UPS changes this equation by providing its equipment two source of power.
UPS are designed so that there is one source of power normally used called the primary power source and another source that kicks in if the primary is disrupted called the secondary power source. The power from the wall is always one of those sources and the battery contains within the UPS is the other. A switch is used to control each of these powers and the equipment of any given time. The switch changes from the primary of the secondary when it detects the primary has gone out. It switches back from the secondary power the primary power, source has returned.
Contrary to what you might think, the wall A.C power is not always the primary power source and the battery the secondary source. Which source is primary and which is secondary depends on the type of UPS. Therefore, circuit is provided with this UPS to convert AC power to DC to change the battery. A device called an invert is also provided to change the battery stone DC electricity to AC to run your equipment.
Furthermore, those components of the uninterruptible power supply and other one discussed in details in the section covering the various parts of the UPS. The size of the UPS is primary dictated by the size of the time your equipment can run on battery power switching down, higher units not only can power equipment for more time they can also handle a large total demand for power.
TABLE OF CONTENTS
Title Page
Certification
Dedication
Table of Contents
CHAPTER ONE
1.0 Introduction
1.1 Background of the study
1.2 Aims of the study
1.3 Scope of the study
1.4 Definition of terms
CHAPTER TWO
2.0 Complete Circuit Description
2.0 Simplified block diagram of thee 3-way intercom system
2.1 Operation Principles
2.2 Conversion
2.3 Inversion
2.4 Power Source
2.5 Oscillator
CHAPTER THREE
3.0 Construction
3.1 Circuit Diagram
3.2 Component and Key Symbol
3.3 Sequence of Operation
3.4 Testing and Result
CHAPTER FOUR
4.0 Observation
4.1 Summary
4.2 Suggestion
4.3 Explanation of the Switching Circuit
4.4 Conclusion
4.5 Reference