(19)
(11) EP 0 587 142 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
30.03.1994 Bulletin 1994/13

(43) Date of publication A2:
16.03.1994 Bulletin 1994/11

(21) Application number: 93114422.4

(22) Date of filing: 08.09.1993
(51) International Patent Classification (IPC)5: H01F 38/18
(84) Designated Contracting States:
DE FR GB

(30) Priority: 09.09.1992 JP 240528/92
21.09.1992 JP 250988/92

(71) Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Kadoma-shi, Osaka 571 (JP)

(72) Inventor:
  • Takeuchi, Toshinobu
    Sanda-shi, Hyogo-ken (JP)

(74) Representative: Marx, Lothar, Dr. et al
Patentanwälte Schwabe, Sandmair, Marx Stuntzstrasse 16
81677 München
81677 München (DE)


(56) References cited: : 
   
       


    (54) A rotary transformer


    (57) The rotary transformer of this invention includes a cylindrical inner magnetic core portion and a cylindrical outer magnetic core portion enclosing the inner magnetic core portion. The inner magnetic core portion and the outer magnetic core portion are rotatable with respect to each other about a common axis. The inner magnetic core portion has windings as a first coil on the outside surface, and the outer magnetic core portion has windings as a second coil on the inside surface. The inside surface opposes the outside surface of the inner magnetic core portion with a predetermined distance therebetween. Either the outer magnetic core portion or the inner magnetic core portion can be made from a resin ferrite, or both outer and inner magnetic core portions can be made from the same resin ferrite.






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