●All specifications in this catalog and production status of products are subject to change without notice. Prior to the purchase, please contact NEC TOKIN for updated product data.

●Please request for a specification sheet for detailed product data prior to the purchase.

●Before using the product in this catalog, please read "Precautions" and other safety precautions listed in the printed version catalog.

9603FERVOL05E1001T0

Ferrite Cores VOL.05

6

Terms and Definitions

●Alternating current initial magnetic permeability

μi

At the initial magnetization curve's origin point, the magnetic

permeability of the magnetic core is used as shown in the formu-

la below.

μ

Here

μ

H : alternating current magnetic field strength (A/m)

B : alternating current magnetic flux density (T)

●Effective magnetic permeability

μ

e

In the magnetic core of a closed magnetic circuit (one in which

flux leakage can be ignored), this refers to the magnetic perme-

ability indicated in the following formula through the effective

self-inductance.

Here L : effective self-inductance (H)

N : Number of all windings

M: Magnetic path lengths (cm) of each of the same mate-

rials and same cross-section areas

μ : Each of the materials' magnetic permeabilities

Note : The first formula is used in measurement and the second

in calculating when the dimensions and magnetic permeabilities

of each part of the magnetic core are given.

●Effective saturation magnetic flux density Bms(G ; T)

This refers to the saturation magnetic flux density in actual use.

●Effective saturation residual coercive force Brms(G ; T)

This refers to the magnetic flux density when the magnetic field

is removed from the condition of effective saturation magnetic

flux density.

●Effective saturation coercive force Hcms(Oe ; A/m)

When the magnetic field is removed from the condition of effec-

tive saturation magnetic flux density and further magnetized in

the opposite direction, this refers to the strength of the magnetic

field in which the magnetic flux becomes 0.

●Loss factor tan

δ

This refers to the hysteresis loss factor, vortex current loss fac-

tor and residual loss factor. The hysteresis loss coefficient

B

H

lim

H

0

1

μ

0

m = tan m

B

m

θ

H

θ

i

μ

θ

μθ

Ba : saturation magnetic flux density

Bms : effective saturation magnetic flux density

Bm : maximum magnetic flux density

Brs : saturation residual magnetic flux density

Brms : effective saturation residual magnetic flux density

Br : residual magnetic flux density

B

Hcs : saturation coercive force

Hcms : effective saturation coercive force

Hc : coercive force

Hms : effective saturation magnetic field strength

Hm : maximum magnetic field strength

Bs

Bms

Brs

Bm

Br

Hcs

Hcms

Hc Hm

Hcms

Hms

H

∞

H

Brms

Hc

μ

L

4

⋅

R

A

∑

μ

R

A

R

∑

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