Ferrites and accessories
Cautions and warnings
Mechanical stress and mounting
Ferrite cores have to meet mechanical requirements during assembling and for a growing number
of applications. Since ferrites are ceramic materials one has to be aware of the special behavior
under mechanical load.
As valid for any ceramic material, ferrite cores are brittle and sensitive to any shock, fast changing
or tensile load. Especially high cooling rates under ultrasonic cleaning and high static or cyclic loads
can cause cracks or failure of the ferrite cores.
For detailed information see Data Book 2007, chapter “General – Definitions, 8.1”.
Effects of core combination on A
L
value
Stresses in the core affect not only the mechanical but also the magnetic properties. It is apparent
that the initial permeability is dependent on the stress state of the core. The higher the stresses are
in the core, the lower is the value for the initial permeability. Thus the embedding medium should
have the greatest possible elasticity.
For detailed information see Data Book 2007, chapter “General – Definitions, 8.2”.
Heating up
Ferrites can run hot during operation at higher flux densities and higher frequencies.
NiZn-materials
The magnetic properties of NiZn-materials can change irreversible in high magnetic fields.
Processing notes
– The start of the winding process should be soft. Else the flanges may be destroid.
– To strong winding forces may blast the flanges or squeeze the tube that the cores can no more
be mount.
– To long soldering time at high temperature (>300 °C) may effect coplanarity or pin arrangement.
– Not following the processing notes for soldering of the J-leg terminals may cause solderability
problems at the transformer because of pollution with Sn oxyd of the tin bath or burned insulation
of the wire. For detailed information see Data Book 2007, chapter “Processing notes, 2.2”.
– The dimensions of the hole arrangement have fixed values and should be understood as a
recommendation for drilling the printed circuit board. For dimensioning the pins, the group of
holes can only be seen under certain conditions, as they fit into the given hole arrangement. To
avoid problems when mounting the transformer, the manufacturing tolerances for positioning the
customers’ drilling process must be considered by increasing the hole diameter.
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Important notes
The following applies to all products named in this publication:
1. Some parts of this publication contain
statements about the suitability of our products for
certain areas of application.
These statements are based on our knowledge of typical
requirements that are often placed on our products in the areas of application concerned. We
nevertheless expressly point out
that such statements cannot be regarded as binding
statements about the suitability of our products for a particular customer application.
As
a rule, EPCOS is either unfamiliar with individual customer applications or less familiar with them
than the customers themselves. For these reasons, it is always ultimately incumbent on the
customer to check and decide whether an EPCOS product with the properties described in the
product specification is suitable for use in a particular customer application.
2. We also point out that
in individual cases, a malfunction of passive electronic components
or failure before the end of their usual service life cannot be completely ruled out in the
current state of the art, even if they are operated as specified.
In customer applications
requiring a very high level of operational safety and especially in customer applications in which
the malfunction or failure of a passive electronic component could endanger human life or health
(e.g. in accident prevention or life-saving systems), it must therefore be ensured by means of
suitable design of the customer application or other action taken by the customer (e.g.
installation of protective circuitry or redundancy) that no injury or damage is sustained by third
parties in the event of malfunction or failure of a passive electronic component.
3.
The warnings, cautions and product-specific notes must be observed.
4. In order to satisfy certain technical requirements,
some of the products described in this
publication may contain substances subject to restrictions in certain jurisdictions (e.g.
because they are classed as “hazardous”).
Useful information on this will be found in our
Material Data Sheets on the Internet (www.epcos.com/material). Should you have any more
detailed questions, please contact our sales offices.
5. We constantly strive to improve our products. Consequently,
the products described in this
publication may change from time to time.
The same is true of the corresponding product
specifications. Please check therefore to what extent product descriptions and specifications
contained in this publication are still applicable before or when you place an order.
We also
reserve the right to discontinue production and delivery of products.
Consequently, we cannot guarantee that all products named in this publication will always be
available.
6. Unless otherwise agreed in individual contracts,
all orders are subject to the current version
of the “General Terms of Delivery for Products and Services in the Electrical Industry”
published by the German Electrical and Electronics Industry Association (ZVEI).
7. The trade names EPCOS, EPCOS-JONES, Baoke, Alu-X, CeraDiode, CSSP, MLSC,
PhaseCap, PhaseMod, SIFI, SIFERRIT, SIKOREL, SilverCap, SIMID, SIOV, SIP5D, SIP5K,
UltraCap, WindCap are
trademarks registered or pending
in Europe and in other countries.
Further information will be found on the Internet at www.epcos.com/trademarks.
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