A method of, and an apparatus for, retracting the head and braking the drive motor of a record disk file

摘要

One phase (A) of a multi-phase spindle motor (10), normally used to rotate the disk of a record disk file when power is on, is used to supply power to a capacitor storage circuit (50) when power is lost (by being turned off or otherwise interrupted). The capacitor storage circuit (50) provides the power to a head retract circuit (90), which retracts the head. The combination of the generator effect of the phase (A) and the capacitor storage circuit (50) provides power to the retract circuit (90) for a time sufficient to reliably retract and lock the head regardless of the bias of the head prior to power loss.;Simultaneously with one phase (A) of the motor being used to retract the head, the other phases (B, C) of the motor are shorted together to provide regenerative braking.;Preferably, the capacitor storage circuit is used as a line filter circuit when power is on.