High-frequency transformer is a power transformer whose working frequency exceeds intermediate frequency (10kHz). It is mainly used as high-frequency switching power transformer in high-frequency switching power supply, and also used as high-frequency inverter in high-frequency inverter power supply and high-frequency inverter welding machine. 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, a half-bridge power conversion circuit, when working, two switching transistors are turned on in turn to generate a high-frequency pulse wave of 100kHz, and then the voltage is transformed through a high-frequency transformer to output alternating current, and the ratio of turns of each winding coil of the high-frequency transformer is determined. the output voltage. The most conspicuous in a typical half-bridge transformer circuit are three high-frequency transformers: main transformer, drive transformer and auxiliary transformer (standby transformer). Each transformer has its own measurement standard in national regulations, such as the main transformer, As long as it is a power supply above 200W, the core diameter (height) must not be less than 35mm. As for the auxiliary transformer, it is enough for the magnetic core diameter to reach 16mm when the power supply does not exceed 300W.

　　A transformer is a device that transforms AC voltage, current, and impedance. When an AC current passes through the primary coil, an AC magnetic flux is generated in the iron core (or magnetic core), which induces a voltage (or current) in the secondary coil.

　　The 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 the secondary coil.