Operation analysis of the push-pull piezoelectric inverter

Operation of the push-pull inverter with a piezoelectric transformer is analyzed. The piezoelectric transformer is used in the third-order longitudinal vibration mode to produce a high output voltage to light up a cold cathode fluorescent lamp. The load characteristics of the inverter are analyzed using an equivalent circuit of the piezoelectric transformer. The ZVS conditions are derived using simplified equivalent circuits to determine the ZVS operation region. These analytical results are confirmed by experiments.