Patent ID: 7143002

Claim:
A method for detecting an external acceleration applied to a hard disk drive, said method comprising: obtaining a running current value applicable to a spindle motor operating in conjunction with hard disk drive operation, said running current value obtained from a controller coupled with said hard disk drive, said controller for maintaining proper rotational speed of a data storage disk in said hard disk drive; compensating said running current value for positional orientation of a data transducer relative to magnetic data located on said data storage disk and for torque disturbance wherein a bearing system associated with said hard disk drive is used as a part of determining said torque disturbance, said data transducer coupled with said hard disk drive; filtering said running current value to remove motor noise and direct current offset, wherein said running current having been subject to said compensating and said filtering provides an estimated external acceleration amplitude; monitoring said estimated external acceleration amplitude; and invoking a defensive action for preventing damage to said data transducer and said data storage disk and loss of data disposed on said data storage disk, said defensive action performed by said hard disk drive, said invoking triggered when said estimated external acceleration amplitude exceeds a threshold value.