Why are high frequency transformers smaller than other transformers?

- Nov 29, 2019-

The improvement of efficiency is a common requirement of today's power supply and electronic equipment. The traditional transformer can not meet the requirements of today's efficiency. The high-frequency transformer can not only improve efficiency, but also save power resources, and it is much longer than the average transformer in terms of service life. Moreover, it has the dual social and economic benefits of energy conservation and environmental protection. We all know that high-frequency transformers are much smaller than ordinary transformers. Why?

This is due to the magnitude of the induced potential of the transformer, which depends on how much the magnetic flux changes in a unit, that is, the faster the flux changes, the larger the induced potential. Although the core of the high-frequency transformer is small, the maximum magnetic flux is not large, but he works at high frequency, and the magnetic flux changes rapidly. Therefore, it is possible to generate a sufficient potential when the core is small and the number of turns is small, and the low frequency is This is the opposite.

Through the design and calculation of the transformer, the higher the frequency, the smaller the core and the fewer turns per volt under the same power conditions. Designing a high frequency transformer should start with the core. The magnetic core of the switching power supply transformer is mostly a soft magnetic material used in a low magnetic field, which has high magnetic permeability, low coercive force and high electrical resistivity. The magnetic permeability is high, and when a certain number of turns of the coil is used, a relatively high applied voltage can be withstood by a small excitation current, and therefore, the core volume can be reduced under the requirement of outputting a certain power.