Disk Drive DC Motor Braking Circuits
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-28
The circuits described are used in disk files to brake the spindle to a stop at either power down or on request. Braking the spindle is required to reduce wear on the disk file heads which results from contact with the disks as the spindle velocity drops below the head-flying speed. To brake the spindle, the DC motor phases can be shorted to a common point. This causes the back EMF (electromotive force) voltage to be shorted, which actively slows the motor to a stop.