Patent ID: 7969157

Claim:
A fault detection circuit, connected to an inverter circuit with a plurality of outputs, to detect whether one or more of the outputs of the inverter circuit are faulty, wherein the outputs of the inverter circuit are divided into three groups connected to three light source modules respectively, and each light source module comprises at least one lamp, the fault detection circuit comprising: a magnetic unit, comprising a first magnetic winding, a second magnetic winding and a third magnetic winding corresponding to the three group outputs of the inverter circuit; wherein when the outputs of the inverter circuit are normal, total flux generated by the first, second, and third magnetic windings can be canceled out; when one or more of the outputs of the inverter circuit are faulty, the total flux generated by the first, second, and third magnetic windings cannot be canceled out; a magnetic detection winding arranged to detect the total flux generated by the first, second, and third magnetic windings and generate a detection signal; and a signal detection unit arranged to generate an abnormal signal according to the detection signal.