Patent ID: 8120271

Claim:
A multi-lamp driving circuit for driving a plurality of lamp groups, each lamp group comprising two lamps, the multi-lamp driving circuit comprising: an inversion circuit configured to generate electrical signals suitable to drive the plurality of lamp groups; and a current balance circuit electrically connected between the inversion circuit and the plurality of lamp groups, and comprising a plurality of transformer circuits, each transformer circuit comprising one transformer that comprises a first magnetic loop comprising a first primary winding and a first secondary winding, and a second magnetic loop comprising a second primary winding and a second secondary winding; wherein two ends of the first primary winding are connected to one end of the second secondary winding of each of the transformers and one lamp of a corresponding lamp group, respectively, and two ends of the second primary winding of each of the transformers are connected to the inversion circuit and the other lamp of the corresponding lamp group, respectively; wherein the first secondary windings of the plurality of transformers are connected to each other in series to make up a closed loop that conducts a current to balance current flowing through each of the plurality of lamp groups; wherein the second primary winding and the second secondary winding of each of the plurality of transformers are connected to the two lamps of one of the plurality of lamp groups to balance current flowing through the two lamps thereof, respectively, and numbers of turns of the second primary winding and the second secondary winding of each of the plurality of transformers are equivalent.