What is the difference between high-frequency and low-frequency transformers

05/09/2022
In general, the low-frequency transformer refers to the "power frequency transformer", which works at (50Hz) and is used to change the voltage. The iron core of the low-frequency transformer is generally silicon steel sheet with high permeability.
High frequency transformer refers to the transformer that works at high frequency and plays the role of energy conversion. Because the frequency of the magnetic field is very high, eddy currents will be generated in the silicon steel sheet (the conversion speed of small magnets in the silicon steel sheet cannot keep up), so high frequency transformers generally use "high frequency ferrite" as the magnetic core. The difference between high-frequency transformer and low-frequency transformer lies in the difference in frequency and working frequency, which leads to some differences in material selection. The working principle of low-frequency transformer is the same as that of high-frequency transformer. No matter the working frequency is high or low, energy is transmitted through electromagnetic induction.
Since the frequencies of high frequency and low frequency are different, the high frequency can only be used in the circuit with high frequency and the frequency of the excitation source matches the frequency of the transformer, while the low frequency can not be mixed, even if the frequency of high frequency is not matched, it can not be used generally.
If a transformer transmits a certain amount of energy, has a high operating frequency, transmits energy many times in a certain time, and transmits less energy each time, the transformer uses less materials and has a small structural size. Therefore, the coil turns of a general high-frequency transformer are relatively small, and the size can be very small. The coil turns of a low-frequency transformer are relatively large.
For the two types of transformers with the same power, the high-frequency transformer will be much smaller than the low-frequency transformer. In this case, the high-frequency transformer will only be about one tenth of the low-frequency transformer. This is because the low-frequency transformer needs to be protected to reduce the U value. It is made of silicon steel sheet, but the efficiency becomes poor, so it needs to do large-scale heat dissipation.