EN 60205:2006

SLOVENSKI SIST EN 60205:2006
STANDARD
oct 2006
Izračun efektivnih parametrov magnetnih sestavnih delov (IEC 60205:2006)
Calculation of the effective parameters of magnetic piece parts (IEC 60205:2006)
ICS 29.100.10 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD
EN 60205
NORME EUROPÉENNE
July 2006
EUROPÄISCHE NORM
ICS 29.100.10 Supersedes EN 60205:2001

English version
Calculation of the effective parameters of magnetic piece parts
(IEC 60205:2006)
Calcul des paramètres effectifs  Berechnung der effektiven Kernparameter
des pièces ferromagnétiques magnetischer Formteile
(CEI 60205:2006) (IEC 60205:2006)

This European Standard was approved by CENELEC on 2006-05-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in two official versions (English and German). A version in any other language
made by translation under the responsibility of a CENELEC member into its own language and notified to the
Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60205:2006 E
Foreword
The text of document 51/848/FDIS, future edition 3 of IEC 60205, prepared by IEC TC 51, Magnetic
components and ferrite materials, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 60205 on 2006-05-01.
This European Standard supersedes EN 60205:2001.
This European Standard includes the following significant technical changes with respect to
EN 60205:2001:
a) unit of angles through the text are described by using “radian”;
b) new words are added in 2.1 “All angles are in radians”;
l In d g /d l In d g /d
2 2 3 2 2 3
c) replacement, in 3.9, of the equation = by = ;
A Dπ(h − h ) A Dπ(h − h )/2
2 1 2 2 1 2
d) new cores “EL, ER, PQ, EFD and E planar” are added in this edition.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-02-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-05-01
__________
Endorsement notice
The text of the International Standard IEC 60205:2006 was approved by CENELEC as a European
Standard without any modification.
__________
INTERNATIONAL IEC
STANDARD 60205
Third edition
2006-04
Calculation of the effective parameters
of magnetic piece parts
 IEC 2006  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale U
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – 60205  IEC:2006(E)
CONTENTS
FOREWORD.3

1 Scope.5
2 Basic rules.5
3 Formulae for the various types of cores.6
3.1 Ring cores .6
3.2 Pair of U-cores of rectangular section .7
3.3 Pair of U-cores of rounded section.7
3.4 Pair of E-cores of rectangular section .9
3.5 Pair of ETD/EER-cores .10
3.6 Pair of pot-cores .11
3.7 Pair of RM-cores .13
3.8 Pair of EP-cores .16
3.9 Pair of PM-cores.17
3.10 Pair of EL-cores.19
3.11 Pair of ER-cores (low profile) .21
3.12 Pair of PQ-cores.23
3.13 Pair of EFD-cores .25
3.14 Pair of E planar-cores .26

Annex A (informative) Purpose of revision .29

60205  IEC:2006(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
CALCULATION OF THE EFFECTIVE PARAMETERS
OF MAGNETIC PIECE PARTS
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)“). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60205 has been prepared by IEC technical committee 51: Magnetic
components and ferrite materials.
This third edition cancels and replaces the second edition published in 2001, corrigendum 1
(2001). This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) unit of angles through the text are described by using “radian”;
b) new words are added in 2.1 “All angles are in radians”;
l ln d g / d ln d g / d
l
2 2 3 2 2 3
c) replacement, Clause 3.9, of the equation = by = ;
A Dπ()h − h A Dπ()h − h / 2
2 1 2 2 1 2
d) new cores “EL, ER, PQ, EFD and E planar” are added in this edition.

– 4 – 60205  IEC:2006(E)
The text of this standard is based on the following documents:
FDIS Report on voting
51/848/FDIS 51/857/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

60205  IEC:2006(E) – 5 –
CALCULATION OF THE EFFECTIVE PARAMETERS
OF MAGNETIC PIECE PARTS
1 Scope
This International Standard lays down uniform rules for the calculation of the effective
parameters of closed circuits of ferromagnetic material.
2 Basic rules
The following basic rules are applicable to this standard.
2.1 All results shall be expressed in units based on the millimetre, shall be accurate to three
significant figures, but to derive l , A , and V the values of C and C shall be calculated to
e e e 1 2
five significant figures. All angles are in radians.
NOTE The purpose of specifying this degree of accuracy is only to ensure that parameters calculated at different
establishments are identical and it is not intended to imply that the parameters are capable of being determined to
this accuracy.
2.2 A is the nominal value of the smallest cross-section. All the dimensions used to
min
calculate A shall be the mean values between the tolerance limits quoted on the appropriate
min
piece part drawing.
2.3 Calculations are only applicable to the component parts of a closed magnetic circuit.
2.4 All dimensions used for the purpose of calculations shall be the mean value within the
tolerance limits quoted on the appropriate piece part drawing.
2.5 All irregularities in the outline of the core, such as small cut-outs, notches, chamfers, etc.
shall be ignored unless otherwise described.
2.6 When the calculation involves the sharp corner of a piece part, then the mean length of
flux path for that corner shall be taken as the mean circular path joining the centres of area of
the two adjacent uniform sections, and the cross-sectional area associated with that length
shall be taken as the average area of the two adjacent uniform sections.
Calculation of effective parameters l , A and V .
e e e
The effective parameters can be defined as
2 3 2
l = C /C A = C / C V = l A = C / C
e 1 2 e 1 2 e e e 1 2
where
l is the effective magnetic length of the core (mm);
e
A is the effective cross-sectional area (mm );
e
V is the effective volume (mm );
e
–1
C is the core constant (mm );
–3
C is the core constant (mm ).
– 6 – 60205  IEC:2006(E)
3 Formulae for the various types of cores
3.1 Ring cores
X
α
β
r
r
4×
4×
r
ϕ
h h h
X
Section X-X
IEC  584/06
2π
C =
h ln()d / d
e 1 2
4π()1/ d −1/ d
2 1
C =
2 2
h ln()d / d
e 1 2
3.1.1 For ring cores of rectangular cross-section with sharp corners
h = h
e
3.1.2 For ring cores of rectangular cross-section with an appreciable average rounding
radius r
1,7168r
h = h()1− k k =
e 1 1
h()d − d
1 2
3.1.3 For ring cores of trapezoidal cross-section with sharp corners
h()tanα + tan β
h = h()1− k k =
e 2 2
d − d
1 2
3.1.4 For ring cores of trapezoidal cross-section with an appreciable average
rounding radius r
h =()1− k − k
e 1 2
3.1.5 For ring cores of cross-section with circular arc frontal sides
d − d ϕ sinϕ ϕ
 
1 2
h = h − 2sin − −
 
e 2
4sin()ϕ / 2 2 2 2
 
d /2
d /2
d /2
d /2
---
...