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.
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 1MHz. When the transmission power is relatively large, the power device generally uses IGBT. Since IGBT has a shutdown current tailing phenomenon, the operating frequency is relatively low; when the transmission power is relatively small, MOSFET can be used, and the operating frequency is relatively high.
Low-frequency transformers are used to transmit signal voltage and signal power. They can also achieve impedance matching between circuits and have an isolating effect on DC power.