SIST EN 60205:2017

SLOVENSKI STANDARD
01-junij-2017
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SIST EN 60205:2006
SIST EN 60205:2006/A1:2009
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Calculation of the effective parameters of magnetic piece parts
Berechnung der effektiven Kernparameter magnetischer Formteile
Calcul des paramètres effectifs des pièces ferromagnétiques
Ta slovenski standard je istoveten z: EN 60205:2017
ICS:
29.100.10 Magnetne komponente Magnetic components
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60205
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2017
ICS 29.100.10 Supersedes EN 60205:2006
English Version
Calculation of the effective parameters of magnetic piece parts
(IEC 60205:2016)
Calcul des paramètres effectifs des pièces Berechnung der effektiven Kernparameter magnetischer
ferromagnétiques Formteile
(IEC 60205:2016) (IEC 60205:2016)
This European Standard was approved by CENELEC on 2016-12-23. 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 CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, 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 CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60205:2017 E
European foreword
The text of document 51/1149/FDIS, future edition 4 of IEC 60205, prepared by IEC/TC 51 "Magnetic
components, ferrite and magnetic powder materials" was submitted to the IEC-CENELEC parallel vote
and approved by CENELEC as EN 60205:2017.
The following dates are fixed:
(dop) 2017-09-23
• latest date by which the document has to be implemented at
national level by publication of an identical national
standard or by endorsement
(dow) 2019-12-23
• latest date by which the national standards conflicting with
the document have to be withdrawn

This document supersedes EN 60205:2006.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 60205:2016 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated :
IEC 62317-13 NOTE Harmonized as EN 62317-13.

IEC 60205 ®
Edition 4.0 2016-11
INTERNATIONAL
STANDARD
Calculation of the effective parameters of magnetic piece parts

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.100.10 ISBN 978-2-8322-3775-5

– 2 – IEC 60205:2016 © IEC 2016
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions. 7
4 Basic rules applicable to this standard . 7
5 Formulae for the various types of cores . 8
5.1 Ring cores . 8
5.1.1 Ring cores in general . 8
5.1.2 For ring cores of rectangular cross-section with sharp corners . 9
5.1.3 For ring cores of rectangular cross-section with an appreciable average
rounding radius r . 9
5.1.4 For ring cores of rectangular cross-section with appreciable chamfer c . 9
5.1.5 For ring cores of trapezoidal cross-section with sharp corners . 9
5.1.6 For ring cores of trapezoidal cross-section with an appreciable average
rounding radius r . 9
5.1.7 For ring cores of cross-section with circular arc frontal sides . 9
5.2 Pair of U-cores of rectangular section . 10
5.3 Pair of U-cores of rounded section . 10
5.4 Pair of E-cores of rectangular section . 11
5.5 Pair of ETD/EER-cores . 12
5.6 Pair of pot-cores . 14
5.7 Pair of RM-cores . 16
5.8 Pair of EP-cores . 20
5.9 Pair of PM-cores . 21
5.10 Pair of EL-cores . 23
5.11 Pair of ER-cores (low profile) . 25
5.12 Pair of PQ-cores . 28
5.13 Pair of EFD-cores. 31
5.14 Pair of E planar-cores . 33
5.15 Pair of EC-cores . 34
Bibliography . 37

Figure 1 – Ring cores . 8
Figure 2 – Pair of U-cores of the rectangular section . 10
Figure 3 – Pair of U-cores of rounded section . 11
Figure 4 – Pair of E-cores of rectangular section . 12
Figure 5 – Pair of ETD/EER-cores . 13
Figure 6 – Pair of pot-cores . 14
Figure 7 – Pair of RM-cores . 18
Figure 8 – Pair of EP-cores . 20
Figure 9 – Pair of PM-cores . 22
Figure 10 – Pair of EL-cores . 23

IEC 60205:2016 © IEC 2016 – 3 –
Figure 11 – PLT(plate)-cores . 24
Figure 12 – Pair of ER-cores (low profile) . 26
Figure 13 – PLT(plate)-cores . 26
Figure 14 – Pair of PQ-cores . 28
Figure 15 – PQ-cores . 29
Figure 16 – PLT(plate)-cores . 29
Figure 17 – Pair of EFD-cores . 31
Figure 18 – Pair of E planar-cores . 33
Figure 19 – PLT(plate)-cores . 33
Figure 20 – Pair of EC-cores . 35

– 4 – IEC 60205:2016 © IEC 2016
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 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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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, ferrite and and magnetic powder materials.
This fourth edition cancels and replaces the third edition published in 2006 and
Amendment 1:2009. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition, in 5.1, of the drawing of a core of rectangular cross-section with chamfer;
b) addition, in 5.1.3, of the equation of a core of rectangular cross-section with chamfer;
c) equations in 5.1.4, 5.6, 5.7, 5.8, 5.9, 5.11, 5.12, 5.14 are amended or replaced;
d) drawings RM6-S and RM6-R in 5.7 are amended;
e) addition of EC-cores, see 5.15.

IEC 60205:2016 © IEC 2016 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
51/1149/FDIS 51/1156/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – IEC 60205:2016 © IEC 2016
INTRODUCTION
The purpose of this revision is to provide formulae by which everybody can reach the same
effective parameter values. Firstly, it is necessary to have a sufficient number of significant
figures when figures are rounded off in the process of calculation. Additionally, some of the
calculation formulae have been changed to get closer to the actual shape.
In this revision, the basic idea of calculation has not been changed. Recently, analysis of the
magnetic field in the core has been considerably improved, so that, based on these ideas,
development of new approaches and formulae can be expected.
Furthermore, the new “EC-cores” have been added.
The parameters in the existing IEC standards will be revised with the outcome from the
formulae of this document.
IEC 60205:2016 © IEC 2016 – 7 –
CALCULATION OF THE EFFECTIVE PARAMETERS
OF MAGNETIC PIECE PARTS
1 Scope
This document specifies uniform rules for the calculation of the effective parameters of closed
circuits of ferromagnetic material.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Basic rules applicable to this standard
4.1 All results shall be expressed in units based on millimetres, 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.
4.2 A is the nominal value of the smallest cross-section. A is the geometrical cross-
min g
section of a ring core with rectangular shape. All the dimensions used to calculate A shall be
min
the mean values between the tolerance limits quoted on the appropriate piece part drawing. All
results shall be expressed in units based on millimetres, and shall be accurate to three
significant figures.
The minimum physical cross-section area A is given as: A = min (A )
min min i
NOTE A to be used for the measurement of the saturation flux density B on ring cores with rectangular cross-
g max
section.
4.3 Calculations are only applicable to the component parts of a closed magnetic circuit.
4.4 All dimensions used for the purpose of calculations shall be the mean value within the
tolerance limits quoted on the appropriate piece part drawing.
4.5 All irregularities in the outline of the core, such as small cut-outs, notches, chamfers, etc.
shall be ignored unless otherwise described.

– 8 – IEC 60205:2016 © IEC 2016
4.6 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
is the effective magnetic length of the core (mm);
l
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 ).
5 Formulae for the various types of cores
5.1 Ring cores
5.1.1 Ring cores in general
Drawings of ring cores are shown in Figure 1.
X
α
β
c
r
r
4×
4×
r
ϕ
h
X h h h
X-X X-X X-X X-X
IEC
Figure 1 – Ring cores
2π
C =
h ln(d / d )
e 1 2
4π(1/ d − 1/ d )
2 1
C =
h ln (d / d )
e 1 2
d /2
d /2
c
d /2
d /2
IEC 60205:2016 © IEC 2016 – 9 –
5.1.2 For ring cores of rectangular cross-section with sharp corners
h = h
e
The geometrical cross-section of a ring core with rectangular sha
...