Introduction and working principle of high frequency transformer

High-frequency transformer is a power transformer with an operating frequency exceeding medium frequency (10kHz). It is mainly used as a high-frequency switching power supply transformer in high-frequency switching power supplies. It is also used as a high-frequency inverter in high-frequency inverter power supplies and high-frequency inverter welding machines. Power transformer. According to the working frequency, it can be divided into several grades: 10kHz-50kHz, 50kHz-100kHz, 100kHz~500kHz, 500kHz~1MHz, and above 10MHz.

High frequency transformer is the most important component of switching power supply. There are many topologies in switching power supplies. For example, in a half-bridge power conversion circuit, during operation, two switching transistors are turned on in turn to generate a 100kHz high-frequency pulse wave, which is then transformed through a high-frequency transformer to output alternating current. The ratio of the turns of each winding coil of the high-frequency transformer is determined. determines the output voltage. The most conspicuous in a typical half-bridge transformer circuit are the three high-frequency transformers: main transformer, driving transformer and auxiliary transformer (standby transformer). Each transformer has its own measurement standards in national regulations, such as main transformer, As long as it is a power supply above 200W, its core diameter (height) must not be less than 35mm. As for the auxiliary transformer, when the power supply power does not exceed 300W, it is enough for the core diameter to reach 16mm.

A transformer is a device that converts AC voltage, current and impedance. When AC current flows through the primary coil, AC magnetic flux is generated in the iron core (or magnetic core), causing voltage (or current) to be induced in the secondary coil.
A transformer consists of an iron core (or magnetic core) and a coil. The coil has two or more windings. The winding connected to the power supply is called the primary coil, and the remaining windings are called secondary coils.