Transformer including gaps

A transformer comprising:

• an outer peripheral iron core;
• and
• at least three iron core coils formed separately from and surrounded by the outer peripheral iron core, wherein the at least three iron core coils contact an inner surface of the outer peripheral iron core, wherein
• the at least three iron core coils each extend only in a radial direction of the outer peripheral iron core;
• wherein
• the at least three iron core coils each include an iron core, and a primary coil and a secondary coil, which are wound only around the iron core,
• each of radially outside ends of the iron core of the at least three iron core coils are in contact with the outer peripheral iron core, and
• each of radially inside ends of two adjacent ones of the at least three iron cores, around which the primary coil and the secondary coil are only wound, converge on a center of the outer peripheral iron core, are magnetically coupled via a gap including the center of the outer peripheral iron core such that the gap:
• forms a Y-shape between the adjacent inner ends of the at least three iron cores, occurs between each of the two adjacent ones of the at least three iron cores, and extends radially from the converged center of the outer peripheral iron core to only a space located between the coils of the two adjacent iron cores and the inner surface of the outer peripheral iron core.