A light module includes a plurality of light sources for generating light, a power controller, a bridge converter, a first piezoelectric transformer, a second piezoelectric transformer, a resonance balance circuit, and a protection circuit. The power controller is used for generating a power driving signal based on a control signal. The bridge converter is used for generating a supply voltage signal based on the power driving signal. The first piezoelectric transformer is used for transforming the supply voltage signal into a first driving voltage signal to a first end of each of the plurality of lamps. The second piezoelectric transformer is used for transforming the supply voltage signal into a second driving voltage signal to a second end of each of the plurality of lamps. The resonance balance circuit includes a primary winding coupled to the first and the second piezoelectric transformers, and a secondary winding for outputting a feedback signal in response to a current flowing through the primary winding. The protection circuit is coupled to the secondary winding of the resonance balance circuit, and is used for generating the control signal based on the feedback signal.