(19)

(11)

EP 2 939 343 A1

(12)

(43) Date of publication: 04.11.2015 Bulletin 2015/45 (21) Application number: 12891068.4 (22) Date of filing: 28.12.2012

(51) International Patent Classification (IPC):  H03K 17/00(2006.01) (86) International application number: PCT/FI2012/051307 (87) International publication number: WO 2014/102444 (03.07.2014 Gazette 2014/27)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME (71) Applicant: ABB Oy 00380 Helsinki (FI)	(72) Inventors: TAKALA, Marko FI-65300 Vaasa (FI) KÄHKIPURO, Matti FI-05800 Hyvinkää (FI) RANTANEN, Tommi FI-33900 Tampere (FI) (74) Representative: Kolster Oy Ab  Iso Roobertinkatu 23 PO Box 148 00121 Helsinki 00121 Helsinki (FI)