This paper presents theoretical and experimental considerations of the
energy storage characteristics of a piezoelectric generator developed
previously by the authors. In this paper, the oscillating output volt
age induced by mechanical impact via the piezoelectric effect is recti
fied, and the electrical energy is stored in a, capacitor. The effect
of the capacitance of the capacitor and the initial voltage is investi
gated using an equivalent circuit model. A maximum efficiency over 35%
has been achieved with a prototype generator.