Abstract: A system driving a lamp set having a first lamp and a second lamp is provided. The system has a power supply circuit providing an AC signal to the lamp set, and a balance circuit having a current balancing transformer, a first impedance and a second impedance for balancing currents through the first and second iamps. The current balancing transformer includes a first winding and a second winding. The first and second windings are wound on the same magnetic core and have the same winding count. A specific relationship between the first and second impedances balances the current values through the first and second lamps effectively without increasing inductances of the current balancing transformer.

Abstract: A lamp driving system. A lamp set having a first lamp and a second lamp is driving by the system. The system has a power supply circuit providing an AC signal to the lamp set, and a balance circuit having a current balancing transformer, a first impedance and a second impedance for balancing currents through the first and second lamps. The current balancing transformer includes a first winding and a second winding. The first and second windings are wound on the same magnetic core and have the same winding count. A specific relationship between the first and second impedances balances the current values through the first and second lamps effectively without increasing inductances of the current balancing transformer.