Patent ID: 6104566
Filing Date: 2000-08-15
Classification: G11B

Abstract:
A method for variable spindle rotation speed in a direct access storage device (DASD) including a multi-phase, brushless, direct current (DC) spindle motor comprising the steps of:applying a control signal to a plurality of spindle motor drivers for normally operating said plurality of spindle motor drivers in saturation mode during normal read/write operations of the direct access storage device; said plurality of spindle motor drivers including respective pairs of field effect transistors connected to each respective winding of the multi-phase, brushless, direct current (DC) spindle motor; and said control signal normally operating said respective pairs of field effect transistors in saturation mode during normal read/write operation of the direct access storage device;detecting a spindle rotational speed;comparing said detected spindle rotational speed with a predetermined spindle speed range; andresponsive to said detected spindle rotational speed being within said predetermined spindle speed range, enabling said normal read/write operations of the direct access storage device (DASD) and continue applying said control signal to said plurality of spindle motor drivers for normally operating said plurality of spindle motor drivers in saturation mode.