CHAPTER ONE
INTRODUCTION
As the growing population of human race widens the gulf between energy supply
and energy demand, the imbalance in energy availability sent researchers into
excavating for a way of settling this age long squabble. A lasting solution is vested
on alternative use of the renewable energy source, a project that is yet to be
widely applied. Hence, the continuation of the unsettled yearns for sufficient
power. Consequently, the power lines are frequently over loaded resulting to a
trip of power by the action of switch gears or by the load shading process
undertaken by the distribution authorities.
Since it is crystal clear that some institutions such as health related institutions
and some other delicate systems should not be allowed to suffer equally with
their counterparts, Automatic Phase Selector is used to sustain energy
consumption in the time of phase trip. The design of this circuit involves the use
of automatic switches but the details of design varies from place to place, time to
time and also depends on the type of load involved.
This project involves the use of transistor driven relays to affect the change of
phase whenever the voltage condition becomes intolerable in the previous phase
connected.
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1.1 BACKGROUND
The intelligent phase selector is a system that is capable of comparing three
phases and switching automatically to any of the three phases. The system
consists of three main parts namely; the transformer, comparators (which is the
brain of the system) and electrical switching device (relay).
The transformer used here is the step down type of transformer (it step down
240v to 12v) and these transformer is feed in with different phase voltage,
rectified and smooth. Then fed in to a voltage regulator that has positive output.
The regulator outputs were connected to comparators. Here the comparators are
three in number. We call the comparators the brain of the system because these
comparators are connected in a way that each of them will give out an output.
The relay in the system is where the output voltage is connected. In this project
we even went as far as using pictures for illustration of some components.
1.2 AIMS/OBJECTIVES OF THE PROJECT
The analysis of this project cannot go without enumerating the goals meant to be
achieved in the pursuit of the work. These objectives include:-
i. To develop a simple low cost device aimed at easing the prevalent burden
faced by delicate offices, parastatals and institutions who need very low but
constant power supply. Since supply is always on along the distribution lines
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that supply such sites, what pesters on the progress of work thereof is always the unwarranted trip of phases due to power usage from neighboring consumers. The automatic phase selector therefore, erases this setback form the face of progress of work in such offices.
ii. To stimulate the interest of upcoming students to take up research not only in their field of study “Electrical/Electronic Engineering” but also to extend their arms to other disciplines, thus enhancing the versatility of Electrical/Electronic Engineering.
iii. To create awareness that will stimulate the interest of fellow students who intend to take up research topic on automatic switch of any type.
1.3 RELEVANCE OF THE PROJECT
The issue of selecting or switching over manually is now a thing of the past. Nowadays we know that homes and offices enjoy steady power supply once the three phases are available (i.e. red yellow and blue phases). Is just a question of making a quick and automatic three phase selector?
1.4 SCOPE OF THE PROJECT
The scope of the project covers aspects like the features of automatic three phase selector, its applications, and its operations. Its advantages and its components. Finally, it covers the importance on the need of automatic three phase selector
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and contributions toward a greater sharing load balance and a better three phase power distribution and monitoring for domestics consumers.
1.5 LIMITATIONS
Owning to the nature of this project, the research centers and the resources were not easy to come by within the immediate environment. Some of the limitation encountered on the course of this project include financial and time constrains which did not really take much room for additional capacity beyond what is at hand.

This material content is developed to serve as a GUIDE for students to conduct academic research