This paper presented a novel power conversionmethod of realizing the galvanic isolation by dual safetycapacitors (Y-cap) instead of conventional transformer. Withlimited capacitance of the Y capacitor, series resonant isproposed to achieve the power transfer. The basic concept is tocontrol the power path impedance, which blocks the dominantlow-frequency part of touch current and let the highfrequencypower flow freely. Conceptual analysis, simulation and designconsiderations are mentioned in this paper. An 85W AC/ACprototype is designed and verified to substitute the isolationtransformer of a CCFL LCD TV backlight system. Comparedwith the conventional transformer isolation, the new method isproved to meet the function and safety requirements of itsspecification while has higher efficiency and smaller size.