Abstract: A magnetic sensor unit includes an actuator motor and a magnetic position sensor. The actuator motor has a magnetic circuit including motor magnets. The magnetic position sensor includes a sensor magnet and a hall element for detecting magnetic flux. Magnet clearances are formed between the motor magnets. The hall element is disposed outside of the motor to detect the magnetic flux in a direction penetrating through the magnet clearances, and which is perpendicular to a direction from one of the motor magnets to the other. In this disposition of the hall element, it is restricted that the hall element detects leaking magnetic flux from the motor magnets.
Abstract: The inductive position sensor includes a scale (10) with a series of conductive loops spaced out by a pitch T and a cursor (20) provided with conductors forming each a series of alternating hairpin turns spaced out by a pitch T, the inducing (21 to 23; 42, 44) and induced (31 to 33; 41, 43) cursor conductors are laid out in two separate interlaced conductor groups, coupling between inducing and induced conductors of the second group taking place only via the scale loops. Such a sensor is simple, robust, accurate, insensitive to external electromagnetic fields and tolerant of misalignment between cursor and scale.
Abstract: A system (10) and method for high-speed massive magnetic imaging on a spin-stand (12) is provided. The system (10) includes a spin-stand system (12) for driving a rotational spindle (20) to which a magnetic hard disk (30) is mounted. A magnetic read head (40) reads data from disk (30) and is in electrical communication with a universal head preamplification board (50). The universal head preamplification board (50) outputs readable voltage signals which are transmitted to an oscilloscope (60) for displaying a read-back voltage display (70). The signals are processed by a processing means (90) to generate scanned image data (100) on a display means. The display signals (70) are utilized to calibrate the magnetically read data to account for the eccentricity of the hard disks with respect to the center of rotation of the spin-stand spindle. Whole tracks of hard disk data can be imaged through the process of “track-centering” and “track-following”.
Type:
Grant
Filed:
October 31, 2003
Date of Patent:
February 28, 2006
Assignee:
University of Maryland
Inventors:
Chun Tse, Charles S. Krafft, Isaak D. Mayergoyz, Dragos I. Mircea
Abstract: A magnetoelectric converting element is constructed by four or more magnetic resistance segments symmetrically arranged at a predetermined pitch with respect to the central line of a magnet perpendicular to the rotating direction of a magnetic moving body. The magnetizing direction of the magnet is set to the direction perpendicular to the direction opposed to the magnetic moving body. Further, 0.7P?X?P and P?Y?1.6P are set when the size of the magnet in the moving direction of the magnetic moving body is set to X and the size of the magnet in the direction opposed to the magnetic moving body is set to Y and the pitch of the magnetic resistance segments at both ends constituting the magnetoelectric converting element is set to P.
Abstract: A sensor for measuring a clamp arm position in a power clamp provides a sensor wheel that may fit beneath the clamp arm. A low profile sensor body abuts an edge of the sensory wheel to detect the sensor position without undue change in the power clamp or clearance about the power clamp.
Type:
Grant
Filed:
May 13, 2003
Date of Patent:
September 6, 2005
Assignee:
Rockwell Automation Technologies, Inc.
Inventors:
Saeed Shafiyan-Rad, Larry Joseph Fisher, Daniel M. Corbosiero, Jr.