Self-powered adaptive circuit sampling for a piezoelectric harvester

This paper proposes a low-cost true self-powered start-up and control circuitry for an envisaged system based on commercial vibration energy harvesting sources, that is oriented to structural health monitoring (SHM) applications. The proposed circuitry is quite simple and assures a battery less system just working with piezoelectrical generators. This architecture works looking for the maximum mechanical to electrical efficiency conversion, thanks to a continuous check of the open-load voltage at the piezoelectric generator, disconnecting it from the electronic circuitry, defining a true adaptive control unit. Also it is addressed the cold-start of the system. Initial experimental results are provided to verify its performance.