A method for controlling a motorized data-storage device, including
extracting energy from a spindle motor to drive a positioning motor of
the data-storage device and other components, such as circuitry. In
normal operation of one embodiment, a disk is rotated at a constant
velocity by a spindle motor and a read/write head is moved over the disk
surface by a voice-coil motor. In the event of a power failure, energy is
extracted from the spindle motor to drive the voice-coil motor so the
head can be safely moved away from the disk.