Welcome on our presentation. My name is Mateusz and here is my colleague Bartek. We would like to remind you some basic information about transformers.

So let’s take a look at the plan of our presentation. First of all we will cover the construction of a basic transformer. Then we are going to remind you the basis of its operation and the last point will introduce you into the topic of its application. If there will be any questions, please be patient and remember them and at the end of our presentation there will be enough time to answer them.

So, I would like to begin with transformer's construction: As we all know transformers are used to increase or decrease AC voltages. A simple transformer consist of two inductive coupled coils with a soft, laminated iron core. Input voltage is applied across the primary coil and as a result on the secondary coil we are receiving output voltage. Core is made of iron to intensify the magnetic flux. The reason why a core is laminated is to prevent eddy currents. Thus, it increases the efficiency of a machine that might be up to 99,9%. Layers of insulation are inserted between layers of windings to prevent arcing. The transformers are put into an enclosure which is filled with dielectric oil. The oil performs several functions. Mainly it plays a role as an electrical insulation and as a coolant. It also prevent moisture. Large transformers are equipped with fans and radiators for better heat dissipation from the enlarged outside surface.

Now, we will talk about basic operation of a transformer. They operate on the basis of mutual induction principle. When alternating current flows through the primary coli, it produces magnetic field which is continuously changing. Created magnetic flux, which flows through the core, cuts the loops of the secondary coil and as a result an output voltage is produced in accordance with Faradays induction principle. There are two types of transformers. Transformers which are used to decrease voltage are called step-down transformers, and ones that are used to increase voltage are called step-up transformers. The type of a transformer and the size of the output voltage depends on the size of the voltage across the primary coil and the number of turns of wire on the primary and the secondary coils. This relationship between the number of turns in the two windings is called the turns ratio and it’s expressed by the formula:

$$\frac{n_{2}}{n_{1}}$$

Where n is a number of turns in a secondary coil (2) and a primary coil (1).

This is the construction and operation of a transformer in its simplest and shortest form.

Moving to the last point of our presentation lets consider the applications of transformers. I must notice that transformers are very commonly used and they can be found in almost every home. Thanks to them the more efficient energy transmission and distribution is provided and it is why the alternating current is used in a present grids across the world. Large step-up block transformers are used to convert the power plants output energy for high voltage line transmission. At a substation voltage are stepped down and split for further transmission on medium voltages to be lowered again near the consumer to provide proper domestic voltage in case of a standard household. Above that there are small transformers in almost every appliance to convert the voltage to the required level.

To sum up what have been told before we can state that the transformer is an essential part of every electric system and without it the present technological advancement wouldn’t have been reached.

Ending our presentation we would like to thank you for your attention and now if there are any questions we are ready to answer them.