Patent ID: 7439685

Claim:
A current balancing integrated transformer for balancing currents in three parallel branches of a circuit, the transformer comprising: a three-leg magnetic core; and a primary winding and a secondary winding on each of at least two legs, wherein: the primary windings are wound in a same direction; the secondary windings are all wound in an opposite direction with respect to the primary windings; and a configuration wherein: if all legs have windings, the primary winding of each leg is connectable from one similar end to a fluorescent lamp and from the other end is connected or connectable to one similar end of a secondary winding of another leg, and the other end of the secondary windings are connected or connectable to a ground; if all legs have windings, the secondary windings of all legs are connected or connectable in series so that to form a loop, and one similar end of each primary winding is connectable to a respective fluorescent lamp and the other end of each primary winding is connected or connectable to the ground, wherein the primary and secondary windings form a star-delta connection; or if two legs have windings, the primary winding of a first leg and the secondary winding of a second leg are, from one end, connectable to a first and a second fluorescent lamp and from the other end connected or connectable to the ground, and wherein the primary winding of the second leg is connectable from one end to a third fluorescent lamp and from the other end connected or connectable to one end of the secondary winding of the first leg, and the other end of the secondary winding of the first leg is connected or connectable to the ground.