Ferrites and accessories
E 70/33/32
Core and accessories
Series/Type:
Date:
B66371, B66372
April 2018
EPCOS
AG 2018. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS’ prior express consent is prohibited.
EPCOS AG is a TDK Group Company.
E 70/33/32
Core
■
Delivery mode: single units
B66371
Magnetic characteristics
(per set)
l/A
l
e
A
e
A
min
V
e
= 0.22 mm
–1
= 149 mm
= 683 mm
2
= 676 mm
2
= 102000 mm
3
Approx. weight
514 g/set
Ungapped
Mate- A
L
value
nH
rial
N27
N87
N97
N95
8850 +30/–20%
9700 +30/–20%
e
B
S
*
mT
P
V
W/set
Ordering code
1530 320
1700 320
< 19.00 (200 mT, 25 kHz, 100 °C) B66371G0000X127
< 9.50 (100 mT, 100 kHz, 100 °C) B66371G0000X187
< 8.60 (100 mT, 100 kHz, 100 °C) B66371G0000X197
< 11.30 (100 mT, 100 kHz, 25 °C) B66371G0000X195
< 9.00 (100 mT, 100 kHz, 100 °C)
10000+30/–20% 1740 330
13000+30/–20% 2260 330
* H = 250 A/m; f = 10 kHz; T = 100 °C
Gapped
(A
L
values/air gaps examples)
Material
g
mm
N27
N87
1.500.05
2.000.05
2.500.05
4.00.05
A
L
value
approx.
nH
655
520
435
200
e
Ordering code
113
90
75
35
B66371G1500X127
B66371G2000X187
B66371G2500X187
B66371G4000X187
The A
L
value in the table applies to a core set comprising one ungapped core (dimension g = 0 mm)
and one gapped core (dimension g > 0 mm).
Other A
L
values/air gaps and materials available on request – see Processing remarks on page 5.
Please read
Cautions and warnings
and
Important notes
at the end of this document.
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E 70/33/32
Core
Calculation factors
(for formulas, see
“E cores: general information”)
Material
Relationship between
air gap – A
L
value
K1 (25 °C)
N27
N87
Validity range:
903
903
K2 (25 °C)
–0.789
–0.789
Calculation of saturation current
K3 (25 °C)
1568
1485
K4 (25 °C)
–0.847
–0.796
K3 (100 °C) K4 (100 °C)
1470
1438
–0.865
–0.873
B66371
K1, K2: 0.20 mm < s < 5.00 mm
K3, K4: 290 nH < A
L
< 2880 nH
Please read
Cautions and warnings
and
Important notes
at the end of this document.
3
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E 70/33/32
Accessories
Coil former
Material:
B66372A: Polyphenylene suplhide, UL 94 V-0, insulation class to IEC 60085:
F max. operating temperature 155 °C), color code natur
Ryton R-4-280 [E95746 (M)] SOLVAY SPECIALITY POLYMERS
B66372B: GFR ASA/ PBT, UL 94 HB, insulation class to IEC 60085:
H max. operating temperature 130 °C), color code black
Ultradur 4090G6 [E41871 (M)], BASF SE
see Processing notes, 2.1
A
N
mm
2
389
l
N
mm
230.5
A
R
value
20
Pins
–
Ordering code
B66372A2000T001
B66372B2000T001
B66372
Winding:
Sections
1
Please read
Cautions and warnings
and
Important notes
at the end of this document.
4
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Ferrites and accessories
Cautions and warnings
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 tempera-
ture 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, 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, chapter
“General - Definitions, 8.1”.
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.
Ferrite Accessories
EPCOS ferrite accessories have been designed and evaluated only in combination with EPCOS
ferrite cores. EPCOS explicitly points out that EPCOS ferrite accessories or EPCOS ferrite cores
may not be compatible with those of other manufacturers. Any such combination requires prior te-
sting by the customer and will be at the customer‘s own risk.
EPCOS assumes no warranty or reliability for the combination of EPCOS ferrite accessories with
cores and other accessories from any other manufacturer.
Processing remarks
The start of the winding process should be soft. Else the flanges may be destroyed.
– Too strong winding forces may blast the flanges or squeeze the tube that the cores can not be
mounted any more.
– Too long soldering time at high temperature (>300 °C) may effect coplanarity or pin arrange-
ment.
– Not following the processing notes for soldering of the J-leg terminals may cause solderability
problems at the transformer because of pollution with Sn oxyde of the tin bath or burned insula-
tion of the wire. For detailed information see chapter
“Processing notes”,
section 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.
Please read
Cautions and warnings
and
Important notes
at the end of this document.
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