Transformers are common electrical devices which transform, either by increasing or by decreasing, the alternating voltages in electric power applications. Electromagnetic induction, which is the production of a voltage across a conductor in a magnetic field, was discovered in 1831 by Michael Faraday. Transformers use the electromagnetic induction in order to change the voltage from a primary voltage to a secondary one in a circuit. The transformer was designed and invented by Ottó Bláthy, Miksa Déri and Károly Zipernowsky that came from the Austro-Hungarian Empire. They used the transformer in experimental and commercial systems. In 1885, William Stanley, Lucien Gaulard, and Sebastian Ferranti perfected the initial design using electromagnetic induction. One of the most obvious applications of an electrical transformer is in power distribution. A transformer is used to increase or decrease voltage in an AC electrical circuit. Sometimes transformers can be used in order to convert AC power to DC power. One of the problems a transformer addresses is, that the voltage which comes from a power station to go to houses, buildings, etc. is way too high. If transformers were not used to convert the voltage, the second a computer was plugged in, it would explode. That would happen with any home appliance since they are not capable of tolerating such a high current of energy, therefore ending in an explosion. There are transformers all over every house, even though occasionally we do not spot them. These transformers are inside the black plastic case which is plugged into the wall in pursuance of recharging a cell phone or any other devices. The earlier mentioned transformer types are often called “wall warts”. They can be very large and powerful, as in national utility systems, or they can be very small embedded inside electronic devices. Transformers are an essential part of all electronics nowadays. The first AC power system that used the modern transformer was in Great Barrington, Massachusetts in 1886. Earlier forms of the transformer were used in Austro-Hungary 1878-1880s and 1882 onward in England. Lucien Gaulard (French) used his AC system for the revolutionary Lanzo to Turin, Northern Italy electrical exposition in 1884. In 1891 mastermind Mikhail Dobrovsky designed and demonstrated his 3 phase transformers in the Electro-Technical Exposition at Frankfurt, Germany. (Center, 2018) A transformer consists of at least two coils of wire wrapped around a laminated iron core. The basic components of a transformer are the following;Laminated CoreIt is made with a laminated steel sheet in all type of transformers to provide a continuous magnetic path and also minimum air gap. WindingsSingle-phase transformers have one primary and one secondary winding. On the other hand, three-phase transformers consist of three primary and three secondary windings which connects to each other with proper methods. Low voltage winding is always placed on the inner side of the core. High voltage is placed above the low voltage winding. Insulating materialsInsulating paper and cardboard are used in transformers to isolate primary and secondary winding from each other and from the transformer core.Oil GaugeIt is used for the measurement of oil in a transformer. It displays the level of oil. It is used in medium to high voltage transformers.Tap ChangerIt is used to regulate secondary voltage in case of low voltage in the primary side of a transformer. Two types are used:Offload switch: used to change winding voltage ratio. It is used only in transformer’s off condition.On Load Switch: it can be used with an on load transformer.Oil ConservatorIt is a box made of steel, where the core is placed inside this tank. Windings and other devices are placed inside as well. It is filled with insulating oil, and it usually has a cylindrical or cubical shape depending on the construction. BreatherIt is a device used for the breathing of transformers. When hot oil expands, air goes out of the transformer and when oil contracts after cooling, air enters the transformer. One side of the breather is connected to the oil conservator tank. Cooling Tubes/FansOil temperature gauge provides on or off signal for the cooling fans. When the temperature becomes greater than 75ºC, the oil gauge turns on the cooling fans. Buchholz RelayThis relay provides protection for low oil level and high temperature. It is connected to a pipe between the main tank and conservator tank. Explosion VentIt provides protection to the transformer from greater pressure. Occasionally greater pressure is developed inside a transformer due to the decomposition of oil. The vent is a necessary part of a high power transformer. The transformer can burst without the explosion vent. Transformers burst above 1.01kg/cm³ of pressure. (Microcontrollers Lab, 2018)In order for a transformer to work, it needs an alternating current which will create a changing magnetic field. The changing magnetic field will induce a changing voltage in a coil. The way transformers work is first by the primary coil being connected to an AC supply. Then an alternating current has to pass through the primary coil wrapped around a soft iron core. The alternating current then produces a changing magnetic field, which induces a changing voltage in the secondary coil. The changing voltage will induce an alternating current (AC) in the circuit that is connected to the secondary coil.There are two types of different transformers; step-up transformers and step-down transformers. In a step-up transformer, the potential difference across the secondary coil is greater than the potential difference across the primary coil, since it has more turns on the secondary coil than on the primary coil. What a step-up transformer is used for, is to increase the voltage from a power station 25 kV to up to 400 kV. In a step-down transformer, the potential difference across the secondary coil is smaller than the potential difference across the primary coil, since it has fewer turns on the secondary coil than on the primary coil. What a step-down transformer is used for, is to decrease the voltage from the mains supply from 230V to 18V. The reason why transformers are used is because, without them, we would not be able to charge our electronic devices. Also, the reason voltage that comes from a power station is so high is due to the fact that the higher the voltage used, the greater is the efficiency of energy transmission. Energy is lost to heat because of the cables’ resistance when using lower voltages. The greater the energy loss is the more money that is lost. This device interacts a lot economically since it prevents companies and power stations from losing energy which they are supposed to deliver. In the end, transformers make our life much easier since we are able to do daily things without having to worry about the voltage that comes to our homes. They are such a technological advance which allow more technological advances to be made.