What is the function of the transformer?

What is the function of the transformer? As the name suggests, transformer certainly has the function of voltage transformation. In addition, it also has the function of transforming impedance, current transformation and isolation circuit. It is widely used in power system. Generally, the number beginning with t is often used as the symbol of the equipment circuit, such as T202, T05, etc. There are many types of transformers. If they are divided according to different classification methods, there are many different types of transformers with different functions.

Transformer is a device that uses the principle of electromagnetic induction to change AC voltage. The main components are primary coil, secondary coil and iron core (magnetic core). The main functions are: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. It can be divided into: power transformer and special transformer (electric furnace transformer, rectifier transformer, power frequency test transformer, voltage regulator, mining transformer, audio transformer, medium frequency transformer, high frequency transformer, impulse transformer, instrument transformer, electronic transformer, reactor, mutual inductor, etc.)
There are usually three types of transformers. The first is divided according to the number of power phases, the second is divided according to the cooling mode, and the third is divided according to the working frequency, as follows:
The first division method: according to the number of power phases, it can be divided into single-phase transformer, three-phase transformer and multi-phase transformer.
The second type can be divided into dry-type transformer and oil immersed transformer according to the cooling mode. The former is often a transformer with small capacity, which is usually used for local lighting and other places. Its cooling mode is to cool it through air convection; The latter is generally used in large environment lighting and other places, using oil for cooling and self cooling.
The third type can be divided into the following four types according to the working frequency:
1. Pulse transformer: it usually appears in pulse circuit. For example, the line output transformer in our TV is one of them.
2. Low frequency transformer: components for voltage conversion or impedance matching, mainly including audio transformer and power transformer.
3. Medium frequency transformer: also known as medium frequency transformer, it not only has the characteristics of low-frequency transformer, but also has the characteristics of resonance at a fixed frequency. It is widely used, such as radio, TV, if transformer and so on.
4. High frequency transformer: it is also used in many fields, such as magnetic antenna in radio, antenna impedance matcher in TV, etc.