Patent ID: 8072156

Claim:
A discharge lamp operating system comprising: a first discharge lamp operating circuit including a first primary winding, a second primary winding, a first secondary winding, a first discharge lamp coupled to the first primary winding, and a second discharge lamp coupled to the second primary winding; a second discharge lamp operating circuit including a third primary winding, a fourth primary winding, a second secondary winding coupled in series with the first secondary winding, a third discharge lamp coupled to the third primary winding, and a fourth discharge lamp coupled to the fourth primary winding; a first closed magnetic-circuit core including a first mid leg, a first outer leg and a second outer leg disposed on both sides of the first mid leg, a first connecting leg coupling the first mid leg and the first outer leg, and a second connecting leg coupling the first mid leg and the second outer leg; and a second closed magnetic-circuit core including a second mid leg, a third outer leg and a fourth outer leg disposed on both sides of the second mid leg, a third connecting leg coupling the second mid leg and the third outer leg, and a fourth connecting leg coupling the second mid leg and the fourth outer leg; wherein the first primary winding is wound around one of the first connecting leg and the first outer leg; wherein the second primary winding is wound around one of the second connecting leg and the second outer leg; wherein the first secondary winding is wound around the first mid leg; wherein a number of turns of the first primary winding is equal to a number of turns of the second primary winding; wherein the first primary winding and the second primary winding are formed so that magnetic flux generated in the first primary winding and magnetic flux generated in the second primary winding perform a differential operation in the first outer leg, the second outer leg, the first connecting leg, and the second connecting leg; wherein the third primary winding is wound around one of the third connecting leg and the third outer leg; wherein the fourth primary winding is wound around one of the fourth connecting leg and the fourth outer leg; wherein the second secondary winding is wound around the second mid leg; wherein a number of turns of the third primary winding is equal to a number of turns of the fourth primary winding; wherein the third primary winding and the fourth primary winding are formed so that magnetic flux generated in the third primary winding and magnetic flux generated in the fourth primary winding perform a differential operation in the third outer leg, the fourth outer leg, the third connecting leg, and the fourth connecting leg; wherein a number of turns of the first secondary winding is equal to a number of turns of the second secondary winding; and wherein the first secondary winding and the second secondary winding are formed so that current generated in the first secondary winding and current generated in the second secondary winding flow in an identical direction.