Patent ID: 8093824

Claim:
A backlight driving system, comprising: an inverter module to provide electrical signals to drive a plurality of lamps; a current balance module comprising a plurality of first balance transformers, each comprising a low voltage winding and a high voltage winding connected between one end of one of the plurality of lamps and the inverter module, wherein the low voltage windings of the plurality of first balance transformers are connected in series to balance currents flowing through the plurality of lamps; a feedback module comprising a feedback circuit and a feedback transformer comprising a primary winding, wherein the primary winding of the feedback transformer is connected in series with the low voltage windings of the plurality of first balance transformers to detect the currents flowing through the plurality of lamps and a secondary winding connected to the feedback circuit to generate a feedback signal to the inverter module accordingly; and an open-lamp protection detection module comprising an open-lamp protection detection circuit and a detection coil wrapped around the feedback transformer to detect voltage variations of the feedback transformer; wherein the open-lamp protection detection module generates a detection signal when the open-lamp protection detection module detects the voltage variations and transmits the detection signal to the inverter module.