What Is High Frequency Transformer Leakage Sense

- Jun 28, 2018-

What is high frequency transformer leakage sense

We know that transformer is mainly composed of primary coil, secondary coil and iron core (also called magnetic core). It is a device that USES the principle of electromagnetic induction to change the ac 

The magnetic field lines produced by the coil cannot all pass through the secondary coil, so the inductance of magnetic leakage is called leakage inductance. Refers to the part of magnetic flux that is missed in the initial stage of the transformer during the coupling process.

he sense of leakage increases with the working frequency, because the working frequency of the power frequency transformer (the working frequency of the power frequency transformer generally refers to 50HZ or 60HZ); The working frequency of high frequency transformer are generally above 1 KHZ, or even hundreds of KHZ), the working frequency is low, can generally for the influence of the leakage inductance of the negligible, but for high frequency transformer, it is particularly important to reduce the leakage inductance is, now more and more high frequency switch power supply requirements, transformer has become an important indicator to measure the quality of switch power supply, because it is a great influence on performance of switch power supply, because of the leakage inductance of the circuit causes radiation interference, interference noise for the switching power supply, some of the transformer and blocked, but there will be some interference exists.

Leakage inductance occurs because some primary (secondary) magnetic flux is not coupled through the core to the secondary (primary), but is returned to the primary (secondary) by air closure.
The conductance of a wire is about 109 times that of air, while that of a ferrite core material used in transformers is about 104 times that of air. Therefore, when magnetic flux passes through the magnetic circuit formed by ferrite core, a part of magnetic flux will leak into the air and form a closed magnetic circuit in the air, thus producing magnetic flux leakage. With the increase of working frequency, the magnetic conductivity of ferrite core materials will be reduced. So at high frequencies, it's more obvious.