PIEZOELECTRIC TRANSFORMER WITH VOLTAGE FEEDBACK

摘要

A piezoelectric transformer (200) with voltage feedback is disclosed. The transformer comprises a piezoelectric plate of predetermined length (L), width (W) and height (H) with a driving section (202) having alternatingly stacked plurality of piezoelectric ceramic layers having internal interdigitated layers. A driven section (206) including an unpolarized dielectric section (208), a voltage feedback section (220) in the form of a multilayer electrode structure or an outer strip, and a normally unpolarized dielectric section (222) is also disclosed. The transformer generates an output voltage at an output terminal by the piezoelectric vibration transmitted from the driving section. A feedback control circuit is connected to the voltage feedback section. The isolated voltage feedback provides feedback control to keep the transformer operating at the proper resonant frequency even if there is a change in output load of the transformer.