A shielded power coupling device transferring electric power between a stationary member and a rotating member, the shielded power coupling device comprising: a) a reluctance-decreasing primary core (115; 230; 330) defining a first primary core recess and at least one second primary core recess; b) a reluctance-decreasing secondary core (165; 280; 380) disposed adjacent the primary core (115; 230; 330) and defining a first secondary core recess and at least one second secondary core recess, the primary core (115; 230; 330) and the secondary core (165; 280; 380) being arranged so as to form a core airgap (102; 302) therebetween permitting relative rotation of the primary core (115; 230; 330) and the secondary core (165; 280; 380) about an axis of rotation; c) a first electrically conductive primary winding disposed substantially within the first primary core recess and at least one second electrically conductive primary winding disposed in the at least one second primary core recess, wherein during operation of the shielded power coupling device, the instantaneous net electric current flowing through the primary windings is substantially zero; d) a first electrically conductive secondary winding disposed substantially within the first secondary core recess and at least one second electrically conductive secondary winding disposed within the second secondary core recess; and e) a shield surrounding the primary core (115; 230; 330) and the secondary core (165; 280; 380); f) wherein a first primary electric current flowing through the first primary winding produces a first secondary electric current flowing through the first secondary winding and wherein a second primary electric current flowing through the second primary winding produces a second secondary electric current flowing through the second secondary winding, thereby creating a fringing field at the periphery of the core airgap (102; 302); and g) the shield substantially cancels the fringing field. a) a reluctance-decreasing primary core (115; 230; 330) defining a first primary core recess and at least one second primary core recess; b) a reluctance-decreasing secondary core (165; 280; 380) disposed adjacent the primary core (115; 230; 330) and defining a first secondary core recess and at least one second secondary core recess, the primary core (115; 230; 330) and the secondary core (165; 280; 380) being arranged so as to form a core airgap (102; 302) therebetween permitting relative rotation of the primary core (115; 230; 330) and the secondary core (165; 280; 380) about an axis of rotation; c) a first electrically conductive primary winding disposed substantially within the first primary core recess and at least one second electrically conductive primary winding disposed in the at least one second primary core recess, wherein during operation of the shielded power coupling device, the instantaneous net electric current flowing through the primary windings is substantially zero; d) a first electrically conductive secondary winding disposed substantially within the first secondary core recess and at least one second electrically conductive secondary winding disposed within the second secondary core recess; and e) a shield surrounding the primary core (115; 230; 330) and the secondary core (165; 280; 380); f) wherein a first primary electric current flowing through the first primary winding produces a first secondary electric current flowing through the first secondary winding and wherein a second primary electric current flowing through the second primary winding produces a second secondary electric current flowing through the second secondary winding, thereby creating a fringing field at the periphery of the core airgap (102; 302); and g) the shield substantially cancels the fringing field.