A lighting apparatus includes a lighting module, a feedback control circuit, and a DC-to-AC circuit. The lighting module comprises a first lighting unit, a second lighting unit, a first transformer, a second transformer and a third transformer. A first end of a first port of the first transformer is connected to a first end of the first lighting unit, a first end of a first port of the second transformer is connected to a second end of the first lighting unit, a second end of the first port of the second transformer is connected to a first end of the second lighting unit, and a first end of a first port of the third transformer is connected to a second end of the second lighting unit. The lighting apparatus uses serial connection of the lighting units to reduce the number of transformers and still have the feedback control circuit.