Fujitsu MAE3091LC SERIES, Руководство по эксплуатации продукта

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C141-E064-03EN 1 - 9
(3) Spindle motor
The disks are rotated by a direct-drive hall-less DC motor. The motor speed is controlled by a
feedback circuit using the counter electromotive current to precisely maintain the speed at
±0.5% of the specified speed.
(4) Actuator
The actuator, which uses a rotary voice coil motor (VCM), consumes little power and
generates little heat. The head assembly at the end of the actuator arm is controlled and
positioned via feedback of servo information in the data.
The actuator positions heads on the CCS zone over the disk and is locked by the mechanical
lock when the power is off or the spindle motor is stopped.
(5) Air circulation (recirculation filter, breather filter)
The heads, disks, and actuator are hermetically sealed inside a disk enclosure (DE) to keep out
dust and other pollutants. The DE has a closed-loop air recirculation system. Using the
movement of the rotating disks, air is continuously cycled through a filter. This filter will trap
any dust generated inside the enclosure and keep the air inside the DE contaminant free. To
prevent negative pressure in the vicinity of the spindle when the disks begin rotating, a
breather filter is attached. The breather filter also equalizes the internal air pressure with the
atmospheric pressure due to surrounding temperature changes.
(6) Read/write circuit
The read/write circuit utilizes a read channel mounted with a head IC that supports high-speed
transmission and an EPR4ML (Extended Partial Response Class 4 Maximum Likelihood)
modulation/demodulation circuit in order to prevent errors being triggered by external noise
and to improve data reliability.
(7) Controller circuit
The controller circuit uses LSIs to increase the reliability and uses a high speed
microprocessing unit (MPU) to increase the performance of the SCSI controller.