Multiphase multilamp driving system for LCD back light

This work presents a multiphase multilamp driving system for liquid crystal display (LCD) back light The driving system adopts a multiphase inverter to drive cold cathode fluorescent lamps (CCFL) to reduce input current ripple. Furthermore, to prevent current imbalance among lamps a multiphase transformer is introduced in the proposed system. Compared with the conventional single-phase driving system, the proposed one can have the merit of requiring less number of transformers. A three-phase driving system with current balancing transformer has been built, from which experimental results have verified the feasibility of the proposed multiphases driving system.