Power generating device

A power generating device, comprising:

• a first shell, comprising a plurality of first engaging parts integrally formed on a radial surface of the first shell and extending outward horizontally therefrom, the plurality of first engaging parts having an opening formed therebetween;
• a magnetic unit fixed on the first shell;
• a second shell, comprising an indentation and at least a second engaging part integrally formed therewith, the second engaging part formed on a top surface of the second shell corresponding to the first shell, the second engaging part extending outward vertically from the top surface, the second engaging part detachably engage with the first engaging part so as to form a space between the first shell and the second shell, wherein the magnetic unit is disposed inside the space;
• an inductance coil, disposed on the second shell inside the space;
• and
• an elastic unit embedded in the indentation of the second shell, rather than configured between the first engaging part and the second engaging part;
• wherein, when an external force is applied, the first engaging part moves vertically relative to the second engaging part and at least part of the second engaging part enters the opening vertically during the movement, the inductance coil generates an induced current by sensing changes of a magnetic flux, at least part of the magnetic unit being surrounded by the inductance coil before and after the external force is applied.