9

Ferrites and accessories

Symbols and terms

10/24

L/L

Relative inductance change

H

L0

Inductance of coil without core

H

LH

Main inductance

H

Lp

Parallel inductance

H

Lrev

Reversible inductance

H

Ls

Series inductance

H

Ie

Effective magnetic path length

mm

IN

Average length of turn

mm

N

Number of turns

PCu

Copper (winding) losses

W

Ptrans

Transferrable power

W

PV

Relative core losses

mW/g

PF

Performance factor

Q

Quality factor (Q =

L/Rs = 1/tanL)

R

Resistance



RCu

Copper (winding) resistance (f = 0)



Rh

Hysteresis loss resistance of a core



Rh

Rh change



Ri

Internal resistance



Rp

Parallel loss resistance of a core



Rs

Series loss resistance of a core



Rth

Thermal resistance

K/W

RV

Effective loss resistance of a core



s

Total air gap

mm

T

Temperature

°C

T

Temperature difference

K

TC

Curie temperature

°C

tTime

s

tv

Pulse duty factor

tan



Loss factor

tan

L

Loss factor of coil

tan

r

(Residual) loss factor at H

 0

tan

e

Relative loss factor

tan

h

Hysteresis loss factor

tan

i

Relative loss factor of material at H

 0

U

RMS value of voltage

V

Û

Peak value of voltage

V

Ve

Effective magnetic volume

mm3

Z

Complex impedance



Zn

Normalized impedance |Z|n = |Z| /N2   (le/Ae)

mm

Symbol

Meaning

Unit