Transformation and Load Parameters of the Disk Piezoelectric Transformer

The main aim of this paper is the theoretical analysis and experimental verification of the transformation parameters for the nonhomogeneously poled disk transformer with an excellent transformation ratio and efficiency. The input part is poled in thickness direction and output part in radial direction. Parameters like transformation ratio and efficiency are calculated analytically and measured as a function of resistive load, electrode dimensions, and electromechanical coefficients. The optimum electrode size aspect ratio d/D ≈ 0.4 has been found experimentally. The fundamental as well as higher overtone resonances were studied for the transformation ratio, the optimum resistive load, efficiency, and no-load transformation ratio. All studied disk transformers exhibit very high transformation ratios (U2/U1≈ 50) under no-load conditions and high efficiency (η ≈ 90%) at the optimum load. The presented disk transformer is studied analytically and realized experimentally for the first time. The excellently high transformation ratio allows for the plasma generation at the output electrode.