The piezoelectric transformer has primary and secondary electrodes on the piezoelectric ceramics. The primary electrode is polarized in the thickness direction and the secondary electrode is polarized in the length direction. When a voltage with the resonance frequency is applied on the primary side, a strong mechanical vibration is generated by inverse piezoelectric effect of the ceramics, and a high voltage output from the secondary side, matching its vibration by direct piezoelectric effect.
Compared with traditional electromagnetic inverters, the Piezo inverters have some significant advantages. Due to the lack of high frequencies the Piezo inverters are not influenced by EMI nor do they have EMI emission. They have an extreme operating temperature range of -30°…+80°C, a high efficiency of 90%, and they are producing less heat. A long lamp life time and a high reliability is guaranteed. A further advantage giving more flexibility for the mechanical design is the ultra flat mechanical dimensions. Piezo inverters are UL-approved.