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(11)

EP 0 970 491 A1

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(43) Date of publication: 12.01.2000 Bulletin 2000/02 (21) Application number: 97919817.3 (22) Date of filing: 26.03.1997

(51) International Patent Classification (IPC)7: H01F 27/28 (86) International application number: PCT/SE9700/529 (87) International publication number: WO 9847/159 (22.10.1998 Gazette 1998/42)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (71) Applicant: ABB AB 721 83 Västeras (SE)	(72) Inventors: VALDEMARSSON, Stefan S-725 97 Väster s (SE) HOLMGREN, Tommy S-771 43 Ludvika (SE) ZINDERS, Gunnar S-771 51 Smedjebacken (SE) SANDIN, Björn S-771 60 Ludvika (SE) ELOFSSON, Dan S-771 42 Ludvika (SE) (74) Representative: Olsson, Jan et al Bjerkéns Patentbyra KBP.O.Box 1274 801 37 Gävle 801 37 Gävle (SE)