4.3 Circuit Configuration

4.2.4 Air filter

There are two types of air filters: a breather filter and a circulation filter.

The breather filter makes an air in and out of the DE to prevent unnecessary pressure around the spindle when the disk starts or stops rotating. When disk drives are transported under conditions where the air pressure changes a lot, filtered air is circulated in the DE.

The circulation filter cleans out dust and dirt from inside the DE. The disk drive cycles air continuously through the circulation filter through an enclosed loop air cycle system operated by a blower on the rotating disk.

4.3 Circuit Configuration

Figure 4.1 shows the power supply configuration of the disk drive, and Figure 4.2 shows the disk drive circuit configuration.

(1) Read/write circuit

The read/write circuit consists of two circuits; read/write preamplifier (PreAMP) and read channel (RDC).

The PreAMP consists of the write current switch circuit, that flows the write current to the head coil, and the voltage amplifier circuit, that amplitudes the read output from the head.

The RDC is the read demodulation circuit using the Modified Extended Partial Response (MEEPR), and contains the Viterbi detector, programmable filter, adaptable transversal filter, times base generator, data separator circuits, RLL (Run Length Limited) encoder and servo demodulation circuit.

(2) Servo circuit

The position and speed of the voice coil motor are controlled by closed-loop servo using the servo information recorded on the data surface. The servo information is an analog signal converted to digital for processing by a MPU and then reconverted to an analog signal for control of the voice coil motor.

The MPU precisely sets each head on the track according on the servo information on the media surface.

(3) Spindle motor driver circuit

The circuit measures the interval of a PHASE signal generated by counter- electromotive voltage of a motor and controls the motor speed comparing target speed.

C141-E221

4-3

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Fujitsu MHV2040AS, MHV2080AS, MHV2060AS manual Circuit Configuration, Air filter, Servo circuit, Spindle motor driver circuit
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MHV2060AS, MHV2080AS, MHV2040AS specifications

Fujitsu's MHV series of hard disk drives, specifically the MHV2040AS, MHV2080AS, and MHV2060AS models, are designed to deliver efficient performance and reliability for a range of applications, particularly in desktop computing and entry-level servers. Each of these drives adheres to the Serial ATA (SATA) interface, which ensures compatibility across a wide range of systems and is known for its cost-effectiveness and simplicity.

The MHV2040AS features a storage capacity of 40GB, making it suitable for basic computing tasks including document editing, web browsing, and media playback. The MHV2060AS steps it up with a 60GB capacity, allowing for increased data storage needs while still maintaining a high level of performance. The largest of the trio, the MHV2080AS, offers an impressive 80GB of space, positioning it well for users who require additional room for applications, games, and multimedia files.

All drives in this series are equipped with a rotational speed of 5400 RPM, which strikes a balance between speed and power consumption. This speed is adequate for everyday tasks and allows for quick boot times and file access, making them ideal for home and small office environments. Additionally, the drives feature an average latency of 5.5 milliseconds, contributing to their overall performance in retrieving data.

In terms of technology, the MHV series employs a fluid dynamic bearing (FDB) motor, which not only enhances reliability but also reduces noise levels during operation. The FDB technology helps improve the longevity of the drives by minimizing wear on mechanical components. This characteristic is particularly important for users seeking quieter drives, especially in work environments that require minimal disruption.

The drives also incorporate advanced power management features that significantly reduce power consumption, making them an environmentally friendly choice for users mindful of their carbon footprint. These drives are equipped with energy-saving modes that optimize their performance when not in full use, ensuring lower operational costs and longer lifespan.

Overall, the Fujitsu MHV2040AS, MHV2080AS, and MHV2060AS hard drives provide a solid solution for users looking for dependable storage with a range of capacities to fit their needs. Their performance, combined with noise reduction technologies and energy efficiency, makes them a notable choice for various computing environments, from single-user desktops to small business applications.
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