Rectifiers for Piezoelectric Transformers

In some applications the piezoelectric transformers represent an interesting alternative to the conventional transformers with electromagnetic coupling. The piezoelectric transformer output voltage is generated by the piezoelectric effect. This voltage is generated as a result of charge generation. When designing rectifier and filter circuits, it is necessary to take into account the different behaviour and properties compared to electromagnetic transformers. In this paper the problems with rectification of the piezoelectric voltage are described. The paper describes the rectifier and filter circuits usable for the piezoelectric transformers. The facts presented in the article are applicable for all systems where the piezoelectric voltage needs to be rectified e.g. piezoelectric energy harvesting.