Patent ID: 7443108

Claim:
A power system for driving a plurality of lamps, comprising: a transformer circuit comprising a plurality of transformers in a quantity denoted by N, each of the transformers having a first secondary winding, having a first output end and a second output end, and a second secondary winding, having a third output end and a fourth output end; a current balancing circuit comprising a plurality of current balancing units, each of the current balancing units having two output ends, wherein the number of the current balancing units is twice the quantity N of the transformers, and the (2N)th current balancing unit is connected to a fourth output end of the Nth transformer, and the (2 N−1)th current balancing unit is connected to a first output end of the Nth transformer; and a light source having a plurality of lamps, each of the lamps having one end connected to a respective output end of the current balancing units and another end grounded, wherein the number of the lamps is four times the quantity N of the transformers.