The loss of the electronic transformer includes core loss (iron loss) and coil loss (copper loss). Iron loss as long as the electronic transformer input work, has been the main part of the loss of electronic transformers. Therefore, the selection of core materials according to the iron loss is the main content of the design of the electronic transformer, and the iron loss has become a main parameter for the evaluation of soft magnetic materials.
The iron loss is related to the working flux density and working frequency of the magnetic core of the electronic transformer, when the iron loss of the soft magnetic material is introduced, the loss under what work flux density and what operating frequency must be explained. For example: p0.5/400, indicating a loss of iron at work flux density of 0.5T and 400Hz of working frequency. The p0.1/100k represents a loss of iron at work flux density of 0.1T and 100kHz of working frequency. Soft magnetic materials include hysteresis loss, eddy current loss and residual loss. Eddy current loss is inversely proportional to the resistivity of the material. The larger the rho, the smaller the eddy current loss. The order of various soft magnetic materials from big to small is as follows: Mn-Zn ferrite is 108~109μω?cm, Fe-ni-based amorphous alloy is 150~180μω?cm, fe-based amorphous alloy is 130~150μω?cm, cobalt-based amorphous alloy is 120~140μω?cm, and high Magnetic guide slope mo Alloy is 40~ 80ΜΩ?CM, Fe-Si-Al alloy is 40~60μω?cm, iron-aluminum is 30~60μω?cm, silicon Steel is 40~50ΜΩ?CM and Fe-CO alloy is 20~40μω?cm. Therefore, the 106~107 of Mn-Zn ferrite is higher than that of metal soft magnetic material, and the eddy current in high frequency is small and the application is dominant. However, when the working frequency exceeds a certain value, the insulator inside the Mn-Zn ferrite particles is penetrated and melted, and the rho becomes quite small, and the loss rapidly rises to a high level, which is the limit working frequency of Mn-Zn ferrite.