I too have had similar problems with saturating inductors. Your inductor design may be just too efficient; if you can achieve the necessary inductance on an open former such as a bobbin the you will find that it is almost impossible to saturate one of those.
Best regards Neil R. Barker CEng MIET FSEE MIEEE Manager Quality Engineering e2v technologies (uk) ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: (+44) 1245 453616 Fax: (+44) 1245 453571 Mob: (+44) 7801 723735 From: [email protected] [mailto:[email protected]] Sent: 06 October 2006 15:17 To: [email protected] Cc: [email protected]; [email protected] Subject: Re: Inductor mystery Hi K. I've had this kind of problem in the past on Mains filters. My problem was the core material was saturating, at the far ends of the BH curve. This non linearity actually boosted emissions around 2MHz! The cure was to space the inductor core halves apart with about 0.05mm of plastic shim to increase reluctance and to keep the cores away from saturation. Worked for me! Regards, Chris Duprés Kbalasubramanian@ scmmicro.co.in Sent by: To [email protected] [email protected], [email protected] cc 06/10/2006 13:02 Subject Inductor mystery Dear Experts, We use the inductor part "1812CS-102XJLC" of Coilcraft in our RFID product as EMI filter. Continuously we face one issue, about 20 to 30 % products are functionally failing due to this inductor. While we change the inductor alone the product passes the functional tests. Hence we studied the characteristics of the inductor. Measurements carried out using the Agilent Impedance analyser 4294A shows the failing inductors and passing inductors are identical with respect to the below listed parameters for the entire measuring range of 40 Hz to 110 MHz. Our frequency of operation is 13.56 MHz and both the failing inductors and passing inductors are identical in this particular frequency also with respect to the below parameters. Is there anything else than the below listed parameters critical for an inductor? Has any one of you come across such an issue in your devices? I request your help. a. Ra.c b. Conductance - 'G' c. Reactance - 'X' d. Susceptance - 'B' e. Impedance - 'Z' f. Phase angle of the impedance g. Value of R, L & C measured using the equivalent circuit method of measurement. Sincerely K.Balasubramanian Project Leader - Hardware. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
