ABSTRACT

Despite all attempt of the federal government to have not only an uninterrupted power supply for all cities in Nigeria, but a voltage that is inconformity with the recommended 220/230v for domestic consumption for example. The NEPA Plc is facing some difficulties in generating, transmitting and distributing the required voltage stabilizer, which could be connected, to the main and then the load is in turn connected to it.
This automatic, AC voltage stabilizer has two major sections.
The transformer section, the control circuit unit the third section is the protective unit.
The output of this voltage stabilizer after series of test were performed on it has a voltage 228 + 12 at an overall output power of 1.5 KVA.

CHAPTER ONE

INTRODUCTION
There are many fundamental different types of stabilizers in use some of which are electron mechanically tap changer, solid state tap changer etc. voltage, stabilizer came into being not by normal design and plain, but as a means of solving electrical “Crisis” situation. This crisis situation does rarely occur in developed countries of the world such as Britain, American, Germany etc, why?
Their system of generation, transmission and distribution of electricity is such that a devoid of variation of fluctuation in the supplied voltage. Now, by the definition given by K.G Jackson and R. Feinberg, a voltage stabilizer is a piece device incorporated in a circuit to maintain a constant output voltage from a poorly generated power supply. A voltage stabilizer like any other piece of equipment is a combination of many electrical and like any other piece of equipment is a combination of many electrical and electronic and circuit with the aim of getting the assemble to perform a specified desired task or function.
Therefore a voltage stabilizer consist for four basic unit
1. The transformer unit
2. The control circuit
3. The protective system
4. The display of monitor (which is optional)

1.1 THE TRANSFORMER UNIT
Thereja B.L. defined a transformer as static piece of apparatus by means of which electric power is one circuit is transformed into power 7 some frequency in another circuit. The power can either be raised or covered. If it is referred to as a step-up transformer but if it is lowered, it is referred to as a step transformer being the one applicable to this project work.

1.2 THE CONTROL CIRCUITRY
This is bike an integrated circuit hat is made of microscopically small transistors, diodes, resistors and components connected together. It is used as complete and is amplifier, voltage amplifier is a comparators connected together. It is used as a complete audio amplifier, voltage amplifier is or comparators to mention just a few of its application. An operational amplifier (op. Amp) is widely sued type of IC, which is designed to manipulate very differences in voltage. The op-amp does the same work has comparator simply because it compares two voltages and provide and output signal when one is bigger.

1.3 AIM AND OBJECTIVE OF THE PROJECT
Most electrical appliance this day highly sophisticated to the entreated that cases of intermitted or regular power outages, under voltages or over voltages are not tolerate in them. The initial outlay and the cost or repair (in case of damage) are so economical that is means of maintain steady or regulated a.c power supply to these expensive appliance/equipment must sought for.
The cost of purchasing some already made imported voltage stabilizer is enormous. Not readily available in our local markets while importing them requires high foreign exchange, the sown tunes is also much before, there is need to embark on this project work the design and construction automatic voltage stabilizer any form of voltage fluctuating (under voltage or over voltage) from the NEPA mains supply to domestic and industrial consumer premise. It is also one of the objectives of this project work that cost comparison between the imported or factory assembled voltage stabilizer e.g SORTEX OR BINATONE products and a locally fabricated voltage stabilizer be embarked on and that work be done on this project in order to finally produce a device that would perform optimally and also relatively cheaper.