API BF User Manual

BF SERIES
Split Ferrite Suppressors for Round Cables
Actual Size (BF2125)
Suppressors
Electronic cables and wires, by virtue of their length-to-width ratios, are perfect natural antennas. In the presence of high speed microprocessor signals, cables will conduct, radiate and/or receive unwanted high frequency interfering signals. Radio interference sources usually radiate their RFI power at frequencies above 30 MHz by way of the main cabling, which acts as an antenna. Control of radio interference can be assured by proper placement of an insertion loss device, such as a ferrite suppressor. Any device used to block an RFI signal between its source and a receiver is an electromagnetic interference (EMI) shield. The measure of this ability to attenuate RFI is shielding effectiveness, "SE", which is expressed in decibels, "dB", the ratio of field strength on one side of the shield to the other side.
One of the most versatile and cost effective shielding methods that can be used today is the API Delevan bisected ferrite cable snap assembly. The bisected styling, or familiar clamshell enclosure design offers the ultimate in adaptability. The RF absorbing material interacts directly with unwanted high frequency energy and dissipates it effectively while allowing data signals to pass unimpeded.
Bisected ferrites have a concentrated, homogeneous magnetic structure with high permeability. These are consistently stable at +20°C to +60°C and provide RF suppression without eddy current losses.
POSITION OF SUPPRESSOR The suppressor should normally be located close to the cable termination where it exits the enclosure. Where a cable connects two enclosures containing RF sources, a suppressor on each end may be required. For circuits within an enclosure, a position close to the RF is best. However, other locations along the circuit may work as well.
Material and U.L. Data API-1 Material, see characteristics and information in the Technical Notes Section of our website, www.delevan.com.
Continued on next page
Actual Size (BF2125)
AIR GAP EFFECT
The air gap in bisected ferrites actually extends current carrying capabilities with only an extremely small reduction in impedance versus solid ferrites of the same size. The gap is magnetically insignificant while it is electrically significant as a discontinuation, thereby accommodating more current.
270 Quaker Rd., East Aurora NY 14052 • Phone 716-652-3600 • Fax 716-652-4814 • E-mail: apisales@delevan.com • www.delevan.com
1/2009
BF SERIES
Suppressors for Round Cables
DIMENSIONS
Inches ± 0.04; mm ± 1.0
P
A
R
T
N
U
MB
E
R
BF2930
BF2223
BF1719
BF1835
BF1125-5
BF1125-3
BF1429
BF1225
BF3024
BF2125
BF2123
BF1835-9
BF3121
B
O
D
Y T
U
N
YPE
IT
S
SERIES BF - FOR ROUND CABLES
1.16
in.
A
29.6
mm
in.
0.87
A
mm
22.3
in.
0.70
A
mm
17.8
in.
0.70
B
mm
18.0
in.
0.46
B
mm
11.7
0.46
in.
B
11.7
mm
0.57
in.
C
14.5
mm
0.50
in.
C
12.8
mm
1.20
in.
D
30.5
mm
0.84
in.
D
21.5
mm
0.84
in.
D
21.5
mm
0.73
in.
E
18.6
mm
1.24
in.
D
31.5
mm
A
B
1.20
30.5
0.91
23.3
0.76
19.5
0.77
19.7
0.51
13.0
0.51
13.0
0.61
15.7
0.57
14.7 —
C D L
0.51
13.0
0.39
10.0
0.25
6.5
0.35
9.0
0.19
5.0
0.13
3.5
0.22
5.6
0.15
4.0
0.45
11.4
0.32
8.15
0.32
8.15
0.35
9.0
0.59
15.0
1.30
33.0
1.28
32.6
1.28
32.5
1.37
35.0
0.98
25.0
0.98
25.0
1.14
29.0
0.98
25.0
0.69
17.7
0.77
19.7
0.66
16.8
1.22
31.0
0.60
15.2
MPED-
I
NCE
A
OHMS)*
(
25 MHz
0.94
24.0
1.01
25.8
0.90
23.0
1.38
35.2
0.84
21.5
Suppressors
100 MHz
155
136
171
112
96
139
85
82
51
50
42
126
41
257
250
325
172
154
191
157
146
103
107
94
174
95
Physical Parameters
Material and U.L. Data API-1 Material, see characteristics and information in
the Technical Notes Section.
Note Impedance is typical, based on 1⁄2 turn (4.0") 18 AWG wire. Impedance
*
measurement using HP4191A.
Color Black; Special colors Available for bases on a non-cancellable, non returnable basis C = Cream; W=White; Gr = Grey
U.L. Recognized
All plastic and adhesive components use U.L. Recognized materials with Flammability Ratings of UL94V-0, UL-510 or UL-746C
SEE Z vs. f GRAPHS ON NEXT PAGE
270 Quaker Rd., East Aurora NY 14052 • Phone 716-652-3600 • Fax 716-652-4814 • E-mail: apisales@delevan.com • www.delevan.com
1/2009
BF SERIES
Split Ferrite Suppressors for Round Cables
Suppressors
Additional Information on Preceding Pages
Note Impedance is typical, based on 1⁄2 turn (4.0") 18 AWG wire. Impedance measurement using HP4191A
270 Quaker Rd., East Aurora NY 14052 • Phone 716-652-3600 • Fax 716-652-4814 • E-mail: apisales@delevan.com • www.delevan.com
1/2009
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