What is “effective permeability μe”?
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A. It is the permeability from the effective self-inductance in the magnetic core of a closed magnetic circuit (with a leakage flux that can be ignored) as shown in the following formulas.





  • L : Effective self-inductance (H)
  • N : Total number of turns
  • ℓ : Magnetic path lengths (mm) of each of the same materials and same cross-sectional area parts
  • A : Each of the cross-sectional areas (mm2)
  • : C1 = core constant (mm–1)
  • μ : Permeability of each material


Reference: Formula (1) is used for measurements and formula (2) is used for the dimensions of the various parts of the magnetic core and for calculations when permeability is added.

* Terminology related to ferrites can be found in the website in ”Terms Definitions and Explanations” under ”Ferrite Summary”.
* The symbol and the catalog of this data are in accordance with IEC Publication 60401-3.
* Our terminology and settings were established by reference to JIS C 2560-1,-2.