the present invention comprises a piezoelectric transformer having substantially improved performance . the piezoelectric element is composed of a single crystal of a relaxor ferroelectric piezoelectric material . this element is coupled to input and output electrodes . the element vibrates mechanically in response to an input signal , which causes an output signal to be generated at the output electrodes . improved power transmission is observed despite the reduced mechanical q of the single crystal material , because the coupling and dielectric strength of the material are improved relative to polycrystals .