Patent ID: 8575852

Claim:
A multi-lamp driving system, comprising: a power stage circuit, to convert an input power supply into first alternating current (AC) power signals; a plurality of transformer circuits, connected to the power stage circuit in parallel, to respectively transform the first AC power signals into second AC power signals to drive at least two lamps, each of the plurality of transformer circuits comprising a first primary winding, a second primary winding, a first secondary winding, and a second secondary winding, the first primary winding connected to the second primary winding in series to receive the first AC power signals, and the first secondary winding and the second secondary winding respectively outputting the second AC power signals to drive at least one lamp; an abnormal detection circuit, connected to a junction of the first primary winding and the second primary winding of each of the plurality of transformer circuits, to determine if voltages of the junction of the first primary winding and the second primary winding of each of the plurality of transformer circuits are different to determine if the at least two lamps are normal, and to generate control signals upon the condition that one of the at least two lamps is short or open; and a pulse width modulation (PWM) controller, to output PWM signals based on the control signals to control the power stage circuit.