Disk drive spindle motor start up using an additional motor winding upon startup failure

摘要

A disk drive system for use in limited power applications is disclosed. The disk drive includes a spindle motor having two or more windings, along with a spindle motor driver which can drive the spindle motor in any of a unipolar, bipolar or tripolar mode. The bipolar or tripolar mode is used to start the disk drive and then the unipolar mode is used to operate the disk drive while data is being retrieved. By combining the three drive modes a large start current reduction and higher rotation velocities are achieved. Current consumption is further minimized by adaptively transitioning from bipolar to unipolar modes of operation. The disclosure also includes a general methodology for optimal motor KE and KM parameter selection.