2743037447 Fair-Rite, 2743037447 Datasheet - Page 169

• Manufacturer Part Number: 2743037447
• Description: CHIP BEAD,Ferrite
• Manufacturer: Fair-Rite

Specifications of 2743037447

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14th Edition
P.O. Box J,One Commercial Row, Wallkill, NY 12589-0288
Phone: (888) FAIR RITE / [phone]
DC Bias in Open Magnetic Cores
The discussion so far has been on core types that have a closed
magnetic path, in which a small air gap has been inserted by
either a ground gap or the use of shims. An open magnetic core
can be thought of as a core with a very large fixed air gap. Since
the air gap is determined by the core geometry and cannot be
changed, the Hanna curves can not be used for these types of
cores. Such cores as rods, slugs and bobbins can be used quite
successfully in inductor designs that have relative low induc-
tance values and can accommodate significant amounts of static
currents.
The large air gap will forestall the saturation of this type of core,
hence the inductance will not as rapidly decrease as a function
of the dc ampere-turns. The Fair-Rite bobbins, listed on the
pages 134 and 135 of the catalog, are specified to an inductance
factor or A
of dc ampere-turns, which would reduce the A
more than 5%. For an inductor design the number of turns can
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L
with a tolerance of ± 10% and also by a NI product
100
90
80
70
60
50
40
30
20
10
0
0
Figure 9
1
Percent of original inductance factor vs. DC bias and temperature.
2
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L
3
value but not
Technical Information
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4
DC Bias (A)
5
Fair-Rite Products Corp.
be calculated from the required inductance L and the inductance
factor of the bobbin. N = L / A
current I will give the NI product, which should be less than the
value quoted for the bobbin. For winding fit and dc resistance
check, the same procedure is used as outlined in the example
above, except here the A
winding area. The graphs of Figure 9 show the effect of tempera-
ture on the inductance factor vs. dc bias characteristics of the
9677242409 bobbin. As can be seen from these curves, the
decrease in inductance increases with temperature. The NI
values listed in the catalog are at room temperature, and must be
derated when operating at elevated temperatures. Open mag-
netic cores, rods, slugs and bobbins are used and designed into
SCR and triac controls, speaker crossover networks and differ-
ential-mode input filters. They are also utilized for EMI suppres-
sion applications where relative large direct currents are present
and for output chokes in switched-mode power supplies.
Note: (914) Area Code has changed to (845).
6
100
o
C
7
50
o
C
8
25
w
L
o
, ( L in nH). The turns N times the direct
of the bobbin is the total available
C
9
10
169