A transformer is called an electromagnetic machine designed to raise or lower the voltage in the network. The transformer was invented at the end of the century before last by a Russian engineer named Yablochnikov. That was a long time ago.
The transformer arrangement is quite simple. In its simplest form, it is a core of electrical steel plates , on which two windings are wound. The first winding, which is called the primary, is connected to the source of energy. Second winding, secondary, connected to the consumer - to the load.
If a current is passed through the primary winding connected to the source, this current will create in the core a magnetic alternating current that will be induced in the secondary winding of the EMF (electromotive force). For all transformers, the concept of the coefficient of transformation is used. This is a characteristic of the ratio of the voltage on the primary winding to the voltage on the secondary winding. Also, you can calculate the transformation ratio by the ratio of the number of turns on the windings. W1 / W2 = k, where W1 - the number of turns of the primary winding, W2 - respectively, the number of turns of the secondary winding.
Speaking about the device transformer, it should be said that these electrical machines are divided into up and down. In the event that the voltage on the secondary winding is greater than at the primary, such a transformer is called boosting. And if the secondary voltage is less than the primary voltage, then the lower voltage. The current in the windings always has an inverse relationship with the voltage, and hence with the number of turns. Therefore, the primary winding is made of a wire with a small cross-section, but with a large number of turns. A secondary winding - on the contrary: fewer turns, but a larger cross-section of the wire. The core and yoke are assembled from sheets of electrical steel, as it perfectly conducts the magnetic flux. The sheets are insulated from each other to reduce eddy currents and reduce core losses. This method of assembly increases the efficiency (efficiency).
The device transformer allows you to classify this machine for several more features. For example, in terms of the number of phases, the transformers are divided into three-phase and single-phase. They are also divided according to purpose. In general, we can identify power and special transformers. The power transformer device is designed for transmission and distribution of electrical energy. Special transformers can be very different - these are welding, and measuring, and test, and furnace, and instrumental. Also, they can include autotransformers (this electric machine has a secondary and primary winding connected to one electrical circuit, creating also an electrical connection, not just a magnetic one).
These transformers are not too different in design, since the principle of operation is virtually the same everywhere. Speaking about the device of a welding transformer, for example, it can be said that in addition to a conventional power transformer, a special device has been added that regulates the welding current.