To provide a special electric circuit for converting a generated weak power into a required DC voltage and current, by solving such a problem that, with respect to the purpose of obtaining energy-saving effects by generating power while applying vibration energy generated in a vibration part to a piezoelectric element assembled in a vibration absorbing part, in order to make the energy-saving effects permanent by preventing breakage of the easily-breakable piezoelectric element while enduring long-term use, the quality of impact such as the form of impact to be applied and the strength of impact to be applied becomes an important factor, and also, the generated power from the piezoelectric element is weak, thereby it is difficult to use the generated power directly in the industry.

Power generation is executed by a piezoelectric element while changing vibration energy into an impact wave caused by variations in pneumatic pressure, gas pressure, or hydraulic pressure and applying the impact wave to the piezoelectric element so as to achieve utilization of the weak power, generated by the piezoelectric element, by accumulating the weak power. There is presented a circuit, utilizing a capacitor and a backup power supply, in order to make the weak power, generated in a large amount, chargeable to a high-voltage and high-capacity battery to be charged.