This specification discloses a frequency division type protection device for
portable information processing systems. It is composed of a control unit, a piezoelectric
unit, a frequency division unit and a display unit. When a portable information
processing system experience an unusual voltage, the frequency division unit produces
and sends a frequency division voltage to the control to provide its work voltage.
The piezoelectric unit temporarily stops its job and the display unit shows the
current status of the protection device. The invention can thus protect the portable
information system and the data stored therein.
