EP 0392202 A3 19910403 - USE OF A FINE CRYSTALLINE IRON-BASED ALLOY AS A MAGNET CORE IN AN INTERFACE TRANSFORMER
Title (en)
USE OF A FINE CRYSTALLINE IRON-BASED ALLOY AS A MAGNET CORE IN AN INTERFACE TRANSFORMER
Publication
Application
Priority
DE 3911618 A 19890408
Abstract (en)
[origin: EP0392202A2] In the new digital ISDN communication system, transformation between the mains terminal (2) and terminal units (3) takes place via the so-called S0 interface by means of interface transformers (6, 11). Since the power supply to the terminal units also takes place partly via said transformers, a current imbalance in the conductors (7, 8) or (9, 10) results in a premagnetisation of the transformers. The ISDN requirements imposed on the transformers consequently have to be met even with direct current premagnetisation. Compact transformers with a simple winding structure which meet the ISDN requirements have, according to the invention, a magnet core material consisting of a fine crystalline iron-based alloy containing more than 60 atomic % of iron, more than 50% of whose structure consists of fine crystalline grains with a grain size of less than 100 nm and which has a remanence ratio of less than 0.2 and a permeability in the range from 20,000 to 50,000. <IMAGE>
IPC 1-7
IPC 8 full level
H01F 1/14 (2006.01); C22C 38/00 (2006.01); H01F 1/153 (2006.01); H01F 3/00 (2006.01); H01F 3/08 (2006.01)
CPC (source: EP US)
H01F 1/15308 (2013.01 - EP US); H01F 3/00 (2013.01 - EP US)
Citation (search report)
[AD] EP 0299498 A1 19890118 - HITACHI METALS LTD [JP]
Designated contracting state (EPC)
DE FR GB IT NL SE
DOCDB simple family (publication)
EP 0392202 A2 19901017; EP 0392202 A3 19910403; EP 0392202 B1 19960612; DE 3911618 A1 19901018; DE 59010366 D1 19960718; JP H02295101 A 19901206; JP H0828290 B2 19960321; US 5074932 A 19911224
DOCDB simple family (application)
EP 90104796 A 19900314; DE 3911618 A 19890408; DE 59010366 T 19900314; JP 9196190 A 19900406; US 49792790 A 19900323