Patent ID: 6930848

Claim:
A mobile host device configured to draw electrical energy from an energy storage device, the mobile host device comprising: a disk drive, the disk drive comprising: a disk drive enclosure including a base; a spindle motor attached to the base; a disk positioned on the spindle motor; a generator, the generator being coupled to one of the disk drive enclosure and the mobile host device, the generator including a generator enclosure; a conductive coil disposed within the generator enclosure, a first spring, a second spring and a magnet sandwiched between the first and second springs such that when the motion of the mobile host device causes one of the first and second springs to be in tension, the other of the first and second springs is in compression, causing the magnet to oscillate relative to the coil to generate electrical energy, and a charging circuit, the charging circuit being configured to charge the energy storage device using the electrical energy generated by the generator.