The Rosen-type piezoelectric transformer 48 12 2 mm (Phillips [4]) was chosen for the present research (see Fig. 1).
This unit has a large output to input voltage ratio at the frequency of the maximum output voltage, relatively high power
(up to 5 W), and high input to output insulation (tens of kilovolts). The equivalent circuit of a PT operating near its resonance
point [Fig. 2(a)] includes a resonant network