Patent ID: 8836199

Claim:
A power generation unit comprising: a piezoelectric element including a piezoelectric material; a deforming member adapted to repeatedly deform the piezoelectric element; a pair of electrodes provided to the piezoelectric element; an inductor electrically connected to the piezoelectric element; a first switch disposed between the piezoelectric element and the inductor; a member adapted to detect a timing at which a deformation direction of the deforming member is switched; a full bridge rectifier adapted to rectify a current output from the pair of electrodes; a capacitor electrically connected to the full bridge rectifier, and adapted to store a current supplied from the full bridge rectifier; a second switch disposed between either one of the pair of electrodes and the capacitor; and a control circuit adapted to operate the first switch and the second switch, wherein after a voltage charged in the capacitor reaches a voltage with which the control circuit can drive the first switch and the second switch, the control circuit sets the second switch to an open state, and performs a control of setting the first switch to a shorted state at the timing at which the deformation direction of the deforming member is switched, and then setting the first switch to the open state after a time corresponding to a half cycle of a resonance period of a resonant circuit composed mainly of the inductor and the capacitor has elapsed.