High-frequency transformers are power transformers whose working frequency exceeds the intermediate frequency (10kHz). They are mainly used as high-frequency switching power transformers in high-frequency switching power supplies, and are also used as high-frequency inverters in high-frequency inverter power supplies and high-frequency inverter welding machines. Change the 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.