Design And Construction Of A 220V/110V Step Down Transformer

ABSTRACT

A transformer is an electrical device that transfers energy between two or more circuits through electromagnetic induction. A varying current in the transformer’s primary winding creates a varying magnetic flux in the core and a varying magnetic field impinging on the secondary winding.

Step down transformer: is one whose secondary voltage is less than its primary voltage. It is designed to reduce the voltage from the primary winding to the secondary winding. This kind of transformer “steps down” the voltage applied to it.

As a step-down unit, the transformer converts high-voltage, low-current power into low-voltage, high-current power. The larger-gauge wire used in the secondary winding is necessary due to the increase in current. The primary winding, which doesn’t have to conduct as much current, may be made of smaller-gauge wire.

The aim of this work is to design and construct a step-down transformer with a primary voltage of 220V and a secondary voltage of 110V.

 CHAPTER ONE

1.1                                                        INTRODUCTION

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Electromagnetic induction produces an electromotive force across a conductor which is exposed to time varying magnetic fields. Commonly, transformers are used to increase or decrease the voltages of alternating current in electric power applications.

A varying current in the transformer’s primary winding creates a varying magnetic flux in the transformer core and a varying magnetic field impinging on the transformer’s secondary winding. This varying magnetic field at the secondary winding induces a varying electromotive force (EMF) or voltage in the secondary winding due to electromagnetic induction. Making use of Faraday’s Law (discovered in 1831) in conjunction with high magnetic permeability core properties, transformers can thus be designed to efficiently change AC voltages from one voltage level to another within power networks.

For the course of this work, which is on step down transformer which is used when one travel from a 110V region with your 110V devices to a 220V region, you’ll need a Step Up Converter. And likewise, if you travel from a 220V country to say, America, a 110V country, you will need to convert down using a Step Down Converter.

A step down transformer: is one whose secondary voltage is less than its primary voltage. It is designed to reduce the voltage from the primary winding to the secondary winding. This kind of transformer “steps down” the voltage applied to it.

As a step-down unit, the transformer converts high-voltage, low-current power into low-voltage, high-current power. The larger-gauge wire used in the secondary winding is necessary due to the increase in current. The primary winding, which doesn’t have to conduct as much current, may be made of smaller-gauge wire.

1.2                                        AIM/OBJECTIVE OF THE PROJECT

Step down transformer is designed to reduce the voltage from the primary winding to the secondary winding. This kind of transformer “steps down” the voltage applied to it. The aim of this work is to construct a transformer with a primary voltage of 220V and a secondary voltage of 110V. At the end of this work:

• a transformer with primary voltage of 220V and a secondary voltage of 110V would be constructed.
• Principle of operation of a transformer would be learned
• Different types of transformer will be discussed
• Different types of Cooling systems of a transformer will be discussed

2.3                                         SIGNIFICANCE OF THE PROJECT

A step down transformer is needed to decrease the incoming 220 Volt electricity found in most parts of the world to 110 Volts USA power. It can be safely used continuously for 110 volt American products in countries with 220 volt power supply.

2.4                                          APPLICATION OF THE PROJECT

Step down Transformers are also used extensively in electronic products to decrease (or step-down) the supply voltage to a level suitable for the low voltage circuits they contain. The transformer also electrically isolates the end user from contact with the supply voltage.

2.5                                                 SCOPE OF THE PROJECT

This is a step-down transformer, as evidenced by the high turn count of the primary winding and the low turn count of the secondary. As a step-down unit, this transformer converts high-voltage, low-current power into low-voltage, high-current power. The larger-gauge wire used in the secondary winding is necessary due to the increase in current. The primary winding, which doesn’t have to conduct as much current, may be made of smaller-gauge wire.

In this work, it is possible to operate either of these transformer types backwards (powering the secondary winding with an AC source and letting the primary winding power a load) to perform the opposite function: a step-up can function as a step-down and visa-versa. However, as we saw in this work, efficient operation of a transformer requires that the individual winding inductances be engineered for specific operating ranges of voltage and current, so if a transformer is to be used “backwards” like this it must be employed within the original design parameters of voltage and current for each winding, lest it prove to be inefficient (or lest it be damaged by excessive voltage or current).

Transformers are often constructed in such a way that it is not obvious which wires lead to the primary winding and which lead to the secondary. One convention used in the electric power industry to help alleviate confusion is the use of “H” designations for the higher-voltage winding (the primary winding in a step-down unit; the secondary winding in a step-up) and “X” designations for the lower-voltage winding.

2.6                                           LIMITATION OF THE PROJECT

If the transformer is used “backwards” like this it must be employed within the original design parameters of voltage and current for each winding, lest it prove to be inefficient (or lest it be damaged by excessive voltage or current).