BF1719

API_newlayouts_single:APIcatalog_newlayouts 8/27/10 10:01 AM Page 118 r pp Su es BF SERIES rs so Split Ferrite Suppressors for Round Cables Actual Size (BF2125) 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. 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) 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. 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 API_newlayouts_single:APIcatalog_newlayouts 8/27/10 10:02 AM Page 119 R BF1719 BF1835 BF1125-5 BF1125-3 BF1429 BF1225 BF3024 BF2125 BF2123 BF1835-9 BF3121 C D L rs so E MB BF2223 in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm B Hz 0M 10 z MH 25 NU BF2930 A IMPEDANCE (OHMS)* es T Suppressors for Round Cables PE TY DY S BO NIT U R PA BF SERIES r pp Su DIMENSIONS Inches ± 0.04; mm ± 1.0 SERIES BF - FOR ROUND CABLES 1.16 1.20 0.51 1.30 A 29.6 30.5 13.0 33.0 — 0.87 0.91 0.39 1.28 A 22.3 23.3 10.0 32.6 — 0.70 0.76 0.25 1.28 A 17.8 19.5 6.5 32.5 — 0.70 0.77 0.35 1.37 B 18.0 19.7 9.0 35.0 — 0.46 0.51 0.19 0.98 B 11.7 13.0 5.0 25.0 — 0.46 0.51 0.13 0.98 B 11.7 13.0 3.5 25.0 — 0.57 0.61 0.22 1.14 C 14.5 15.7 5.6 29.0 — 0.50 0.57 0.15 0.98 C 12.8 14.7 4.0 25.0 — 1.20 — 0.45 0.69 0.94 D 30.5 11.4 17.7 24.0 0.84 — 0.32 0.77 1.01 D 21.5 8.15 19.7 25.8 0.84 — 0.32 0.66 0.90 D 21.5 8.15 16.8 23.0 0.73 — 0.35 1.22 1.38 E 18.6 9.0 31.0 35.2 1.24 — 0.59 0.60 0.84 D 31.5 15.0 15.2 21.5 155 257 136 250 171 325 112 172 96 154 139 191 85 157 82 146 51 103 50 107 42 94 126 174 41 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 API_newlayouts_single:APIcatalog_newlayouts 8/27/10 10:03 AM Page 120 r pp Su es BF SERIES rs so Split Ferrite Suppressors for Round Cables 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