Patent ID: 8680962

Claim:
A transformer arranged on a base plate, comprising a lower core, the lower core being made of a magnetic material, having a lower surface and an upper surface and being arranged on the base plate; at least two upper cores including two upper cores made of a magnetic material and arranged face to face over the upper surface of the lower core, the upper surface of the lower core being on the other side of the lower surface of the lower core through which the lower core is arranged on the base plate; a primary coil, and a secondary coil, the primary coil and the secondary coil being arranged between the lower core and the upper cores, wherein: each of the two upper cores is in contact with the lower core, on an outer side of the primary coil and the secondary coil, with two first gaps being provided between the upper core and the lower core, on an inner side of the primary coil and the secondary coil; the two upper cores are each extended from the outer side to the inner side of the primary coil and the secondary coil, in a direction of coming close to each other, with a second gap being provided between opposing surfaces of the two upper cores; a spacer made of a non-magnetic material is provided in each of the two first gaps such that the spacer rigidly connects each of the upper cores and the lower core, the spacer being positioned radially inside the primary and secondary coils; and a pressing device is provided, the pressing device includes a pressing member made of a non-magnetic material and arranged in the second gap such that the pressing member presses the lower core against the base plate the pressing member being prevented from being touched with the opposing surfaces of the two upper cores.