To solve the problem of a generator equipped with a flywheel that the rotation in the direction opposite to that of the flywheel causes speed reduction or stop, and to solve the problem of a conventional monitoring system that, although a power generated by collision between a steel ball and a piezoelectric element is used as the power for detecting opening/closing of a door or window and for wireless transmission, a module size is limited and a small size is not appropriate for acquiring a wanted power.

A first train mechanism for transmitting rotation to a flywheel is set parallel to a second train mechanism for generating reverse rotation, and the rotations of two train mechanisms are transmitted to both end surfaces of the same flywheel. A cavity is formed in both end surfaces of the flywheel for rotation in the same direction at all times. The monitoring system uses a rotational inertia held generator at a primary detector, and uses the algorithm for judgement and control to realize the system configuration for monitoring health which is not referred to by a conventional technology.