機械スイッチ式非線形回路を用いた振動発電素子の高出力化

抄録

A miniature piezoelectric vibration energy harvester represents one promising power source for IoT (Internet of things) device. Recently, a SSHI (Synchronized Switch Harvesting on Inductor) interface was developed to enhance its output power. However, use of external power source or of complicated circuits for switching On/Off poses a practical problem. To address these issues, we propose a mechanical switch for SSHI interface. We employed ball spring plunger and stainless steel thin plate for the mechanical switch. We demonstrated that the mechanical switch properly works as a SSHI interface. The miniature prototype harvester achieved 1.2 mW at the frequency of 35.6 Hz under the acceleration of 0.55 G, a 1.7-fold increase over the standard circuit.