Showing papers on "Magneto published in 1995"

Electro-magneto-mechanical characterizations of the vibration of magnetic origin of electrical machines

Abstract: This paper contributes to the modelling of vibration of magnetic origin of electrical machines. It is generally difficult to calculate the damping matrix of actual mechanical structure of electrical machines. The mechanical model that we present here is known as the modal superposition method. It allows us to take into account the damping coefficients of the mechanical structure which can be inferred from experience. Associated with a numerical code for the computation of magnetic force it can be of a great help in the predetermination of the vibration of an electrical machine. >

Recording and reproduction of items of information using ROM-RAM storage media

Abstract: A magneto optical disc system includes a disc having permanently recorded tracks overlain with magneto optical recording material. Data is recorded in the magneto optical material in tracks superimposed over the permanently recorded tracks, using the read-only data to define magneto optical tracks. The magneto optically recorded data is correlated with the prerecorded data for defining the location of data stored in the magneto-optic tracks.

Vibration exciter machine

Abstract: A vibration exciter machine has magneto striction elements (5,6) supported by a driven pile (2), for providing a vibration of up and down direction to the driven pile (2), and a drive circuit (D1) for controlling expansion and contraction movement of the magneto striction elements (5,6) by changing a supply time period of a current supplied to the magneto striction elements (5,6). By controlling of the drive circuit (D1) the supply time period of the current which flows in the magneto striction elements (5,6) is changed to control the expansion and contraction movement of the elements (5,7). Thereby a horizontal vibration component can be eliminated and only vertical vibration component can be transmitted to the driven pile material (2).

Method and device for magneto-abrasive machining of parts

Abstract: A method of and a device for magnetic-abrasive machining of parts has an external magnetic field providing a magnetic flux, a supply of a magnetic-abrasive powder to the part in the magnetic field The part is rotated and oscillated about the longitudinal axis so that magnetic-abrasive powder is displaced by the rotating part in a circumferential direction A fluid jet is directed toward the magnetic-abrasive powder so as to press the magnetic-abrasive powder against a surface of the part The fluid jet is to improve the material removal rate of machining

Magneto with Dual Mode Operation

Abstract: An ignition system is provided for an internal combustion engine (67) that operates in two modes. In a first mode, the timing of the spark event is under electronic control. In a second mode, the timing of the spark event is fixed and synchronized to the mechanical rotation of the crankshaft (65) of the engine. Under normal operating conditions, the timing of the spark event is electronically controlled. If the electrical system of the engine malfunctions, the ignition system defaults to the second mode in which ignition timing is mechanically controlled.

Magneto-resistive device, and magnetic head comprising such a device

Abstract: A magneto-resistive device comprising a magnetic multilayer structure (9) which is deposited within a connective passage (7) running between and emerging into two opposed surfaces (S1, S2) of a film (5), successive constituent layers of the multilayer structure (9) being located at increasing distance from one of these surfaces (S1, S2). Such a multilayer structure (9) is preferably deposited using electrochemical techniques, and can be incorporated into an ultra-magnetic head employing the so-called CPP measuring geometry.

Magneto-resistive current sensor

Abstract: PROBLEM TO BE SOLVED: To improve measuring accuracy, to dispense with necessity of a secondary coil for allowing second current to flow, and to decrease the size. SOLUTION: A ferromagnetic body magneto-resistive element unit 10 and an operational amplifying circuit unit 20 are formed on the same chip, individual magneto-resistive bodies 11 to 14 are formed into bridge shapes in the ferromagnetic body magnetoresistance element unit 10, at least one of magneto-resistive bodies has a resistance value different from a resistance value of the other magneto-resistive body, and therefore, the magnetic balancing state can be naturally formed in supplying of the stationary current. Since any hall element is not used as in the past, the change by the temperature is not generated, and the measuring accuracy is high, and any secondary coil for allowing secondary current to flow, which has been required for the magnetic balance in the past, is not required.

Giant magneto-transport phenomena in inhomogeneous materials

Abstract: Electronic and magnetic structures in magnetic multilayers and granular alloys are examined. It is shown that the structures govern the giant magnetoresistance. We present a simulation method of the resistance and magnetoresistance based on the recursive Green's function method. By using this method, the dependencies of the magnetoresistance on materials and nanostructure of the systems are derived.

Friction-free dynamo for bicycle lighting

Abstract: The friction-free permanent magnet dynamo comprises an aluminium or plastic disk (1) attached to the spokes of the rear wheel. Around the outer edge are fastened several permanent magnets (2). On the frame of the bicycle is wound the stator winding (3) with an iron core and past which the magnets rotate. This allows the continuous generation of an alternating voltage which can be rectified and used to supply a set of rechargeable batteries, and thereafter lamps, horn, indicator lamps, and even a radio.

Digitally controlled magneto ignition system with alternate timing

Abstract: A digitally controlled magneto provides for the precise control of the timing advance profile for an internal combustion engine. A micro-controller or a micro-processor provides the digital control by using inputs from engine sensors to determine the engine's crank speed and position. With this information, it computes an optimum timing advance angle for the time of spark generation. The digital system controls the spark generation by using a semiconductor switching circuit to interrupt the flow of current generated by the magneto in the primary coil. The current flow interruption results in a high voltage pulse in the secondary coil creating a spark in a spark gap for the initiation of combustion in the internal combustion engine. To maintain the operational reliability of the magneto ignition system, an alternate timing system allows the internal combustion engine to produce full power even if the electrical power supplied to the digital system fails. The invention succeeds in improving the efficiency of the internal combustion engine while maintaining its operational reliability. An increase in efficiency has the advantage of both reducing the engine's toxic exhaust emissions and its specific fuel consumption rate.

Direct access storage device with magneto-resistive transducing head apparatus

Abstract: A direct access storage device includes at least one disk mounted for rotation about an axis and having opposed disk surfaces for storing data. A magneto-resistive (MR) transducer head is mounted for movement across each respective disk surface for writing to and for reading data signals from the disk surface. Each MR transducer head includes a write element and a read element. A preamplifier, associated with the MR transducer head, amplifies read and write signals of the read element and the write element. A flex cable couples the read and write signals between the preamplifier and the MR transducer heads. The flex cable includes a common read return signal line for each sequential pair of the MR transducer heads.

Magneto-optical recording device

Abstract: PURPOSE:To stably perform the recording and the erasure of information by detecting a distance between a biased magnetic field impressing means and a magneto-optical disk and also, controlling a magnetic field strength outputted from the biased magnetic field impressing means. CONSTITUTION:When a distance between an optical head 1 and a magneto- optical disk 4 is obtained with a distance detecting sensor 1c, a distance between the magneto-optical disk 4 and a biased magnetic field generating mechanism 2 can be also obtained. The reason is that a distance between the optical head 1 and the biased magnetic field generating mechanism 2 is known beforehand from a design. Thus, even though the surface wobbling, etc., of the magneto- optical disk are generated, the recording and the erasure of the information can be performed stably because a magnetic field can be impressed on the magneto-optical disk 4 with a desired magnetic field strength.

Magneto-resistive effect sensor

Abstract: A magneto-resistive effect magnetic sensor having a magnetic layer whose resistivity is changed with a recording magnetic field derived from a magnetic recording medium. The magnetic sensor includes a magnetic layer having a magneto-resistive effect and a high-resistance magnetic layer formed on the magnetic layer via a non-magnetic layer. A resistance ratio of the high-resistance magnetic layer to the magnetic layer is set so as to be not less than 2.4.

Magneto-resistance effect type magnetic head

Abstract: PURPOSE:To obtain the extremely high reproduced output of the magneto- resistance effect type magnetic head having magneto-resistance effect elements arranged in such a manner that a magnetosensitive current flows in a direction perpendicular to a magnetic recording medium surface by enhancing the conversion efficiency of the signal magnetic fluxes from this recording medium to the magnetic fields in the magneto-resistance effect elements. CONSTITUTION:The magneto-resistance effect elements formed with the average value Wb of the element width in the magnetosensitive region in the upper part of the medium side flanks (front end of the magneto-resistance effect elements) narrower than the element width Wa of these flanks are used. As a result, the vertical type magneto-resistance effect type magnetic head for reproducing high-density recording signals having the reproduced output better than the reproduced output of the conventional vertical type magneto-resistance effect type magnetic head is obtd.

Measuring method of magnetic field and magneto-optical sensor using that

Abstract: PURPOSE:To obtain a measuring method of a magnetic field of high intensity using RIG which is inexpensive and of high massproductivity, as a magneto- optical material, and to obtain a magneto-optical sensor using this method. CONSTITUTION:The intensity of a magnetic field is measured by using rare earth iron garnet(RIG) as a magneto-optical material. In this method, a magnetic field controlling member 24 made a magnetic material is disposed near the rare earth iron garnet to control the substantial intensity of the magnetic field applied on the RIG to smaller than the saturation magnetic field of the RIG. By constituting the detecting part for a magnetic field of the detecting terminal 23 using the RIG film as a magneto-optical material and the magnetic field controlling member 24 made a magnetic material, even a magnetic field of high intensity which can not be measured with a magneto-optical sensor using a conventional RIG film as a magneto-optical material can be measured. By using the RIG film, improvement in the massproductivity and the cost reduction of the sensor can be realized.

Magneto-resistive effect sensor

Abstract: A magneto-resistive effect magnetic sensor having a magnetic layer whose resistivity is changed with a recording magnetic field derived from a magnetic recording medium The magnetic sensor includes a magnetic layer having a magneto-resistive effect and a high-resistance magnetic layer formed on the magnetic layer via a non-magnetic layer A resistance ratio of the high-resistance magnetic layer to the magnetic layer is set so as to be not less than 24

Faraday Rotation in the UV/VUV and High Field Magneto-Optics

Abstract: Magneto-optics has a long history which predates quantum mechanics by many years. The crucial discoveries were made by Faraday1 in 1846 Kerr2 in 1875 and Zeeman3 in 1896. Electro-optics came later, when lo Surdo4 and Stark5 discovered what is now called the Stark effect, around 1912. Quantum mechanics as such only appeared in 1927.