New topology of resonant converter with minimum switches for AC/AC transformation is suggested. This operates nearly at circuit resonant frequency and guarantees high frequency operation because switching instant always occurs at zero current or zero voltage. Output voltage is controlled by proper selection of the switch mode. The proposed resonant converter is analyzed by approximation method and is modeled as a general AC/AC switching buck converter with equivalent inductance. For 1/2 transformation case, the power circuit is analyzed, designed and simulated. From the simulation, characteristics of this converter coincide with those of equivalent model. Therefore, the new scheme of resonant AC/AC converter applied to electronic transformer has many advantages such as low switching stress, low electromagnetic interference(EMI), low cost and light weight. Some of these characteristics are experimentally verified.
