A cable includes: a linear conductor; a plurality of resin hollow tubes which are disposed around the conductor so that an air layer is formed around the conductor and which extend in a longitudinal direction of the conductor; and an insulating protective member configured to protect the conductor and the plurality of hollow tubes.

A cable includes: a linear conductor; a plurality of resin hollow tubes which are disposed around the conductor so that an air layer is formed around the conductor and which extend in a longitudinal direction of the conductor; and an insulating protective member configured to protect the conductor and the plurality of hollow tubes.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Transformers having a plurality of windings from a single Litz wire, as well as systems including such transformers and methods of providing such transformers are disclosed. A transformer includes a core and a single Litz wire having a plurality of individual strands of conductive material. The plurality of individual strands of conductive material are separated into a plurality of groups, each one of the plurality of groups being a winding of the transformer such that the transformer comprises a plurality of windings.

A noise reduction element includes a protruded portion on which a bent portion of a conductive wire is hooked, and a winder portion around which both a first conductive wire portion extending in one direction from the bent portion of the conductive wire hooked on the protruded portion and a second conductive wire portion extending in another direction from the bent portion of the conductive wire hooked on the protruded portion are wound in a state where the first and second conductive wire portions are parallel to each other.