A disc drive includes a disc mounted to a rotatable spindle, a motor coupled to the spindle, and motor control circuitry. The motor has a motoring mode in which it rotates the spindle and a braking mode in which is decelerates the rotating spindle and generates power. The motor control circuitry is adapted to control the modes of the motor. The disc drive also includes an auxiliary power output that is generated while operating the motor in the braking mode. The auxiliary power output is made accessible to electronic components that are collateral to the disc drive.
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Application No. 60/342,676 filed on Dec. 21, 2001 for inventors Charles W. Thiesfeld and Hakam D. Hussein and entitled "SPINDOWN POWER SAVER."
An electric motor system includes a motor brake control circuit that uses current induced in the motor stator from generated back EMF to keep the motor brake energized and in its disengaged position, should electric power be lost to the motor system. When the motor has slowed sufficiently that the induced current is no longer sufficient to keep the motor brake energized, the motor brake will move to its engaged position, and prevent further motor rotation. The motor rotational speed at which the motor brake is no longer energized is sufficiently low that any potential degradation or other deleterious effects from motor brake engagement are minimized.
