Abstract: An electric transformer comprising a first magnetic circuit coupling a primary coil and a secondary coil, the first magnetic circuit comprising a first limb extending along a vertical axis, the primary coil comprising inner and outer primary coils connected in series, the inner primary coil, the secondary coil, and the outer primary coil being cylindrical and arranged concentrically around the first limb, wherein the inner primary coil, the secondary coil and the outer primary coil are mounted in a manner to maintain a predefined inner gap between the inner primary coil and the secondary coil and a predefined outer gap between the secondary coil and the outer primary coil, the inner and outer gaps being evaluated along a radial direction relative to the vertical axis, the inner and outer gaps increasing a leakage of a magnetic flux between the first coil and the secondary coil.

Abstract: An electric transformer comprising a primary coil, a secondary coil and a first magnetic circuit, the first magnetic circuit comprising at least a first limb and a second limb, the primary coil being wound around the first limb of the first magnetic circuit and the secondary coil being wound around the first limb or the second limb of the first magnetic circuit, wherein the electric transformer further comprises a second magnetic circuit acting as a component for setting a total impedance of the electric transformer at a predetermined value, the second magnetic circuit comprising at least a third limb, only one coil among the primary coil and the secondary coil being wound around the third limb of the second magnetic circuit, the second magnetic circuit being independent of the first magnetic circuit.

Abstract: An electric transformer comprising a coil made of at least one winding, the winding being made of a wire comprising a first section, a second section and a middle section between the first and the second sections, the first section forming a first spiral around an axis (Z) and the second section forming a second spiral around the axis, the first and second spirals being located in two separate planes perpendicular to the axis, an inner end of the first spiral, respectively the second spiral, located near the axis being near the middle section of the winding and an outer end of the first spiral, respectively the second spiral, located away from the axis being near a free end of the winding, the first spiral and the second spiral turning around the axis in opposite directions.