摘要:
The voice coil motor drive unit for a magnetic disk device includes a voice coil motor, a VCM driver, and a waveshaping unit. The voice coil motor has a coil and is driven in positioning and moving a magnetic head. The VCM driver supplies a driving current to the coil of the voice coil motor through a pair of power supply lines. The waveshaping unit shapes the waveform of the driving current supplied from the VCM driver to the voice coil motor into a waveform having a smooth leading edge. The waveshaping unit has a capacitor connected between the power supply lines, and a pair of Zener diodes having the same Zener characteristics and identical poles connected to two poles of the capacitor to be opposite to each other. Each of the Zener diodes has a Zener voltage which is set higher than a voltage applied to the coil in positioning the magnetic head, and lower than the voltage applied to the coil in moving the magnetic head.
摘要:
A DRAM has, in one embodiment, a plurality of word lines each having its upper and side surfaces covered with a first insulating film, a plurality of bit lines each being provided so as to be insulated from and transverse to the word lines and being covered with a second insulating film, and a plurality of memory cells each provided at an intersection between one word line and one bit line and including a capacitor and a memory cell selection transistor, in which contact holes for connection between semiconductor regions and capacitors and between semiconductor regions and bit lines are formed in self-alignment and the second insulating film is made of a material having a permittivity smaller than that of the first insulating film.
摘要:
In a control circuit for a light-emitting device, a reference voltage generation circuit detects a full-wave rectified voltage and generates a first voltage as well as generating a second voltage by converting the rectified voltage into a DC voltage. A voltage corresponding to a difference between the first voltage and the second voltage or a voltage corresponding to a ratio of the first voltage to the second voltage is generated as a reference voltage by a subtraction circuit or by a division circuit, respectively. As a result, a change in amplitude of the reference voltage can be suppressed when amplitude of the rectified voltage is varied due to a variation in an AC input voltage supplied from an AC power supply.
摘要:
In the invention, pairs of output transistors are provided. An actuator having an inductance is connected to nodes formed between the pairs of output transistors. A drive circuit for the actuator is arranged such that the actuator is driven by causing a drive current to flow into the inductance. The drive circuit has an overvoltage detection circuit for detecting whether or not a voltage appearing at the nodes of the output transistor pairs exceeds a supply voltage by a first predetermined level and whether or not the voltage becomes lower than a ground level by a second predetermined level. Output transistors connected to the nodes are activated by an output from the overvoltage detection circuit.
摘要:
In a data base processing system using a multiprocessor system, the data base processing system includes: a storage unit provided in the shared memory for storing data base management information representing either an object of a shared processing operation or an object of a local processing operation for every resource; an access management unit provided in each of the processor modules for performing an access control for an access request to the data base under either the shared processing operation or the local processing operation in accordance with the data base management information, the shared processing operation being symmetrically performed, and the local processing operation being asymmetrically performed in each processor module; and a control unit provided in the processor module for controlling the shared/local conversion in such a way that: an access state of the resource is managed for every resource; when a frequency of the access is unevenly distributed to a particular processor module, the resource of that processor module is determined as the object of the local processing operation at that particular processor module; and when the frequency of the access is not unevenly distributed to a particular processor module, the resource of a particular processor module is determined as the object of the shared processing operation. The data base processing system further includes a deadlock detection system.
摘要:
A magnetic disc apparatus controls the output timing of control current data by use of a servo estimation type observer. Servo information is read from a servo sector of a magnetic disc, decoded, and used to calculate control current data. Before the servo information of the following servo sector is fully decoded, the calculated control current data from the previously read servo sector is output, converted to a current, and sent to the actuator of a magnetic head.
摘要:
A saddle type, off-road vehicle, comprising a frame, an engine supported by the frame, at least one front wheel, a pair of rear wheels disposed on opposite sides of the frame, a seat supported on an upper portion of the frame, and a storage receptacle provided above the rear frame. The storage receptacle includes an element for reinforcing the strength and rigidity of an inner surface thereof and a partition for dividing the receptacle into a plurality of storage sections.