Inverter transformer

An inverter transformer provided in a DC to AC inverter circuit and adapted to step up an AC voltage inputted to a primary side thereof and to output to a secondary side, comprising:

• an outer core shaped substantially like a rectangular frame;
• a plurality of inner cores shaped substantially like a bar, disposed inside the outer core and connected thereto so as to provide a predetermined leakage inductance;
• a plurality of secondary windings provided corresponding to the plurality of inner cores;
• a primary winding common to the plurality of secondary windings;
• and
• a plurality of bobbins shaped substantially like a tube, provided corresponding to the plurality of secondary windings, each of the bobbins including a primary-side terminal block for the primary winding at one end thereof and a secondary-side terminal block for each of the secondary windings at the other end thereof, having each of the inner cores inserted therein, and having each of the secondary windings wound thereon, and the plurality of bobbins, with respective secondary windings wound thereon, being connected together for integration, and having the primary winding wound thereon.