CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE PROJECT
A transformer is a static electromagnetic device that transfers energy by inductive coupling between its winding circuits. In another way, a transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Electromagnetic induction produces an electromotive force within a conductor which is exposed to time varying magnetic fields. A varying current in the primary winding creates a varying magnetic flux in the transformers core and thus a varying magnetic flux through the secondary winding. This varying magnetic flux induces a varying electromotive force (e.m.f) or voltage in the secondary winding. Transformers are used to increase or decrease the alternating voltages in electric power applications. In simple terms, it is an electromagnetic device that steps up or steps down voltages. Making use ofFaraday's Law (discovered in 1831) in conjunction with high magnetic permeabilitycore properties, transformers can be designed to efficiently change AC voltages from one voltage level to another within power networks (Gottlieb, 2012.).
A wide range of transformer designs are used in electronics and electric power applications. Transformers are essential for the transmission, distribution and utilization of electric energy. There are many sizes, shapes and configurations of transformers from tiny to gigantic like those used in power transmission.  Some come with stubbed out wires, others with screw or spade terminals, some made for mounting in PC boards, others for being screwed or bolted down.
Transformers are composed of a laminated iron core with one or more windings of wire.  They are called transformers because they transform voltage and current from one level to another.  An alternating current flowing through one coil of wire, the primary, induces a voltage in one or more other coils of wire, the secondary coils.  It is the changing voltage of AC current that induces voltage in the other coils through the changing magnetic field. DC voltage such as from a battery or DC power supply will not work in a transformer.
Figure 1.1: A typical Transformer
Only AC makes a transformer work.  The magnetic field flows through the iron core.  The faster the voltage changes, the higher the frequency (Edward, 2011). However, the output of transformers various from single to double or multiple.