| 摘要 |
A retract circuit ( 40 ) for retracting a data transducer carriage assembly ( 17 ) of a mass data storage device ( 10 ) to a retracted position has a digital state machine ( 55 ) that is user programmable to operate in a selected retract mode. An analog control circuit ( 44 ) is provided for receiving control signals from the digital state machine ( 55 ) for providing analog retract signals to move the data transducer carriage assembly ( 70 ). The digital state machine ( 55 ) is user programmable to operate in constant voltage, velocity detect, float and pulse, and crash stop detect modes. Preferably, the digital state machine ( 55 ) is programmed to detect a velocity of the data transducer carriage assembly ( 17 ). The digital state machine ( 55 ) also is preferably programmed to detect an error velocity of the data transducer carriage assembly ( 17 ) from a difference of a measured voltage across the data transducer driver ( 22 ) from a predetermined voltage.
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