In Fig. 7a, the power output is limited by the levitating magnet
displacement limit. As seen in the figure, the power reaches a peak
point and then abruptly begins to decrease. This is because the levitating
magnet displacement is limited by the height of the box.
This displacement limit only allows the levitating magnet to move
10 mm from the box center. If the box height were increased, the
power output could be increased, but the application requirements
do not allow an increase in box height. The other option would be
to decrease the levitating magnet height, but this would reduce
the levitating magnet mass, resulting in reduced power output at
lower acceleration amplitudes or when the device is placed at an
angle