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Showing papers on "Magneto published in 1991"


Journal ArticleDOI
TL;DR: In this article, a finite element formulation based on a direct solution of a system of dynamic, nonlinear and coupled magnetothermal equations for ferromagnetic materials in induction heating devices is presented.
Abstract: The authors present a finite element formulation, based on a direct solution of a system of dynamic, nonlinear and coupled magnetothermal equations, for ferromagnetic materials in induction heating devices. This formulation insures a real coupling between the equations. Thus, the results are more precise than those obtained from the classical modeling, and the magnetothermal problem simulations are faster and easier to perform. >

36 citations


Patent
20 Nov 1991
TL;DR: In this article, the lower half of a magneto-resistance effect reproducing head is formed on a substrate by a thin film method and covered with an insulating layer 17, on which a rectangular magneto resistance effect element 12 and leading conductive chips 13, 13' are provided.
Abstract: PURPOSE:To enable the suppression of Barkhausen noise and to easily make the capacity of a disk device larger by winding coils on both end parts of the element of this magneto-resistance effect type reproducing head which uses the magneto-resistance effect of a ferromagnetic thin film, and applying a magnetic field in the longitudinal direction of the element by the current through the coils. CONSTITUTION:The lower half 16 of the coil is formed on a substrate 15 by a thin film method and covered with an insulating layer 17, on which a rectangular magneto- resistance effect element 12 and leading conductive chips 13, 13' are provided, and then an insulating layer 18 and upper half 19 of the coil are laminated. The half coils 16 and 19 are connected through a through hole provided on the layer 17. In this constitution, resistance in the sense region of the element 12 is changed by the magneto-resistance effect according to the magnetic field recorded in a magnetic recording medium 11, and this change is detected as the voltage change in the sense current between the leading chips 13, 13' to reproduce the information. During this process, an electric current is supplied to the coils 14, 14' to control the magnetic domains in the element 12 and to make the sense region as one single magnetic domain state to suppress Barkhausen noise.

11 citations


01 Jan 1991
TL;DR: In this paper, a one-dimensional simulation program for magneto-microwave plasma was developed, which combines a Monte Carlo particle plasma model and an electromagnetic wave damping model.
Abstract: This study discusses modeling of a magneto-microwave plasma used in semiconductor manufacturing equipment such as etching reactors and chemical vapor deposition (CVD) reactors. A one-dimensional simulation program for magneto-microwave plasma was developed. This combines a Monte Carlo particle plasma model and an electromagnetic wave damping model. With the use of this simulation, a plasma production mechanism with electron cyclotron resonance and electromagnetic wave damping in a partially ionized gas can be analyzed. Typical results of the effect of gas pressure on the plasma distribution in plasma processing equipment are presented.

6 citations


Patent
31 Jan 1991
TL;DR: In this article, a three-pole magneto having a magnet positioned in a recess formed at a magnetic rotor is used as a power supply for the ignition system and a transistor switch circuit is used for interrupting a primary current of an ignition coil device, which is capable of significantly increasing an advance angle width.
Abstract: An ignition system of the current interruption type for internal combustion engine wherein a three-pole magneto having a magnet positioned in a recess formed at a magnetic rotor is used as a power supply for the ignition system and a transistor switch circuit is used for interrupting a primary current of an ignition coil device is disclosed which is capable of significantly increasing an advance angle width. Pole arc angles α of a pair of stator magnetic poles are set to be equal to each other and an angular interval α between stator magnetic poles is set to be equal to or less than an angular interval β between rotor magnetic poles adjacent to each other. Also, an angular interval δ between the outer ends of the stator magnetic poles is set to be larger than an angular interval e between the first rotor magnetic pole and the third rotor magnetic pole. Such construction permits a magnetic flux flowing in a core of the ignition coil device to be strained to increase the advance angle width.

5 citations



Patent
27 Dec 1991
TL;DR: In this article, a detection coil is wound around a magneto-sensitive element, inserted and fixed to the central part of a cylindrical permanent magnet, namely, of an auxiliary magnet 2 for set magnetic field.
Abstract: PURPOSE:To exactly induce a pulse at the time of impressing asymmetric set/ reset magnetic fields by interlinking the comparatively large reset magnetic field from the outside to a composite magnetic substance, and inducing electromotive force in a detection coil arranged near the reset magnetic field. CONSTITUTION:In a composite magnetic body 9, a detection coil 3 is wound around a magneto-sensitive element 1, inserted and fixed to the central part of a cylindrical permanent magnet, namely, of an auxiliary magnet 2 for set magnetic field. In respect to this composite magnetic body 9, a main magnet 5 for reset magnetic field with a polarity inverse to the generated magnetic field of the magnet 2 is approached/separated so as to interlink magnetic flux with strength more than regulated. Thus, the pulse signal is induced and by interlinking the magnetic field with strength more than regulated, the pulse signal can be always induced in the almost constant size without depending on the change rate of the interlinked magnetic flux even in the case of approaching/separating the magnet at extremely low speed.

4 citations


Patent
30 Aug 1991
TL;DR: The material characteristics measuring device uses an eddy current method, with a magnetic field generating system and a magneto resistive element within the induced magnetic field for direct measurement of the magnetic field distribution.
Abstract: The material characteristics measuring device uses an eddy current method, with a magnetic field generating system and a magneto resistive element (2) within the induced magnetic field for direct measurement of the magnetic field distribution Pref the device has an insulating substrate (1) carrying a thin-film magnetoresistive element (2) lying adjacent and parallel to the substrate edges The magnetic field generating system uses a coil (5) enclosing the substrate (1) in a plane containing one end edge of the substrate (1), defining the application surface of the measuring device The amplitude and phase of the signal obtained from the magneto-resistive element is evaluated, for display USE/ADVANTAGE - For detecting flaws in construction components or semi-finished goods High sensitivity and resolution

4 citations


Patent
23 Jan 1991
TL;DR: In this article, a toric-shaped magnetic rotor is used to produce magnetic forces which counterbalance the weight of the toric rotor, which will be set in rotation by virtue of the variation in the magnetic field produced by the electromagnets of the magnetic stator.
Abstract: The invention relates to a machine making it possible to operate as a generator and a magneto-electric motor without any loss of mechanical energy by magnetic levitation. This machine consists: 1) of an insulating torus (E) at the surface of which magnets or electromagnets are arranged, in a regular paving 2) of a magnetic stator consisting of static electromagnets which encircle this toric-shaped magnetic rotor, without contact. Under the action of the electric current, this machine will produce magnetic forces which will counterbalance the weight of the toric-shaped rotor (E) which will be set in rotation by virtue of the variation in the magnetic field produced by the electromagnets of the magnetic stator (1,2,3,4,). The applications are the production of electricity, the transformation and conservation of electrical energy, the production of electromagnetic waves.

4 citations


Patent
13 Feb 1991
TL;DR: In this paper, a rotary balancer main body is used to facilitate maintenance and improve reliability by providing permanent magnets on the fixed side and magneto coils in a rotating main body.
Abstract: PURPOSE:To facilitate maintenance and improve reliability by providing permanent magnets on the fixed side and magneto coils in a rotary balancer main body and generating induced currents to the magneto coils by the mutual action between the magneto coils and the magnetic flux of the permanent magnets, thus utilizing this induced current as the power source. CONSTITUTION:Motors 12a, 12b and balance weights 15a, 15b driven by these motors are disposed in a balancer main body 4 fitted at an axis of rotation 2. A light source and permanent magnets 7a-7d are fitted at the supporting part of the axis of rotation, in the opposed position to the balancer main body. Light sensors for controlling the driving of the motors are further fitted in the opposed position to the light source of the main body, and magneto coils are fitted in the main body so as to enable the magnetic flux of the permanent magnets to transverse. The current induced to the magneto coils accompanied by the rotation of the axis of rotation is supplied to the motors and light sensors so as to move the balance weights, and the emission of the light source is stopped in the minimum vibrating position so as to stop the balance weights.

3 citations


Patent
19 Feb 1991
TL;DR: In this article, the authors proposed to keep a gap between a disk and a magnetic field generating coil part constant by providing a first permanent magnet at the outer periphery of optical magnetism, providing additionally a second permanent magnet with polarity having repulsion confronting with the first permanent magnetic magnet, and supporting a terminal part where no second magnet is provided additionally rotatably freely.
Abstract: PURPOSE:To keep a gap between a disk and a magnetic field generating coil part constant by providing a first permanent magnet at the outer periphery of optical magnetism, providing additionally a second permanent magnet with polarity having repulsion confronting with the first permanent magnet, and supporting a terminal part where no second permanent magnet is provided additionally rotatably freely. CONSTITUTION:The repulsion between the first permanent magnet 4 and the second permanent magnet 10 occurs since they are arranged so as to confront their same polarity with each other. The magnitude of the magnetomotive forces of the magnets 4 and 10 are set to keep the gap between a magneto- optical disk 3 and a magnetic core 3 to be almost kept at a constant value d1. Even when camber exists in the disk 3, a distance d2 between the magnets 4 and 10 can be almost kept constant, therefore, the gap between the disk 3 and the core 3 can be kept at the constant value d1.

3 citations


Journal ArticleDOI
TL;DR: In this article, the magnetic and magnetooptic properties of tin-substituted Mn Sb films with bismuth and chromium added were investigated, and it was shown that as the amount of tin substitution increases, the diffraction lines from Mn sb become weak and the saturation magnetization decreases, but perpendicular magnetization films can nonetheless be obtained up to x=0.40 (13.2 at% Sn).
Abstract: Following our previous study on vacuum-evaporated Mn2Sb films with bismuth and chromium added, we have investigated the magnetic and magnetooptic properties of tin-substituted Mn2Sb (Mn2Sb1-xSnx) films, with x varied from 0 to about 0.40 (13.2 at% Sn). Tin was chosen as the third element because there are two magnetic intermetallic compounds with different crystallographic structures in this system--Mn2Sb has a tetragonal structure, while Mn2Sn has a hexagonal structure. As the amount of tin substitution increases, the diffraction lines from Mn2Sb become weak and the saturation magnetization decreases, but perpendicular magnetization films can nonetheless be obtained up to x=0.40. Results show that shrinking along the c-axis of the Mn≪≪MDSD≫≫2≪≪MDNM≫≫Sb lattice occurs in the vicinity of x=0.15 (5 at% Sn), at which a decrease in coercivity and increase in polar Kerr rotation are observed. These are considered to be closely related phenomena, presumably reflecting a change in the electronic structure of Mn2Sb.

Patent
25 Jan 1991
TL;DR: In this paper, a diode laser 24 guides a parallel laser beam onto a magneto-optical disk and the cast beam heats an area on a selected track, adjusting conditions for direct overwriting.
Abstract: PURPOSE: To attain highspeed switching of a magnetic field at low energy by feeding an electric current from a current source to an inductor, with a magnetic head aligned with a laser beam source, and feeding a current with the opposite polarity from other current source if the magnetic field is inverted. CONSTITUTION: A diode laser 24 guides a parallel laser beam onto a magneto- optical disk 10. The cast beam heats an area on a selected track, adjusting conditions for direct overwriting. A magnetic head 30 is provided with an inductor 34 parallelly connected to a capacitor 36. With a switch 38 closed in response to transition in NRZ data, the current with the opposite polarity is supplied from a current source 40 to the inductor 34. With a switch 42 closed in response to the next transition, the current with the opposite polarity is supplied from a current source 44 to the inductor 34. Thus, the current is inverted through the inductor 34 for each transition in NRZ data; accordingly, the magnetic field of the head 30 is inverted.

25 Nov 1991
TL;DR: In this article, a finite element analysis of the dynamic, nonlinear and coupled electro-magneto-thermal equations, that describe induction heating devices, is presented, and the crucial problem of the coupling between the electromagnetic and thermal phenomena is discussed.
Abstract: A finite element analysis of the dynamic, nonlinear and coupled electro-magneto-thermal equations, that describe induction heating devices, is presented. The crucial problem of the coupling between the electromagnetic and thermal phenomena is discussed. The results of the application of an original coupling, based on a finite element solution for a system of electro-magneto-thermal equations, are given. >


Patent
03 Sep 1991
TL;DR: In this paper, the authors propose to quickly separate magnets from each other with a small torque by supporting one of a pair of initializing magnets, which can be moved in such directions that they can approach and go away from a magneto-optical disk, by an elastic member which has an elastic force in such direction that magnets are separated from the other.
Abstract: PURPOSE:To quickly separate magnets from each other with a small torque by supporting one of a pair of initializing magnets, which can be moved in such directions that they can approach and go away from a magneto-optical disk, by an elastic member which has an elastic force in such direction that magnets are separated from each other CONSTITUTION:One magnet 12 of a pair of initializing magnets 8 and 12 can be moved in such directions that it can approach and go away from a magneto- optical disk 101, and this magnet 12 is supported by the elastic member which has an elastic force in such direction that initializing magnets are separated from each other When the disk 101 is set, the magnetic force between initializing magnets causes initilizing magnets to approach each other against the elastic force of the elastic member When the disk 101 is taken out, the elastic force of the elastic member separates initializing magnets from each other against the magnetic force between them Consequently, the process to move the initializing magnets is shortened at the time of taking out the disk 101 Thus, initializing magnets are quickly separated from each other with a small torque

Patent
21 May 1991
TL;DR: In this paper, a superconductor magneto-resistive element 14 is installed in a center portion surrounded by two coils 15 and 16 which generate A.C and D.C. respectively.
Abstract: The superconductor magneto-resistive element 14 is installed in a center portion surrounded by two coils 15 and 16 which generate A.C. and D.C. bias magnetic fields respectively. The coils 15 and 16 are respectively connected to A.C. and D.C. power sources for applying A.C. and D.C. bias magnetic field to the element 14. With the output signal of the element 14, the fundamental component having the frequency component same as that of the A.C. bias magnetic field and the quadratic harmonic component having the frequency component twice as that of the fundamental component are calculated using the Fourier transform. The calculated value of the fundamental component is divided by the value of the quadratic harmonic component, thereby removing the change of the output signal of the element 14 due to the fluctuation inherent in the element 14, enabling to measure an external magnetic field with high accuracy.


Journal ArticleDOI
C.-J. Lin1
TL;DR: The key challenges in media, for the ultra high density MO storage device to be capable of retrieving the stored data' with a final bit error rate of 10-12 or less, are primarily in the disk substrate and the magneto-optical recording layer.

Patent
03 Jul 1991
TL;DR: In this article, the utility model is used for automatically switching the states of charging and discharging the storage battery of the magneto alternator for keeping magnetism, the operation of wrenching a changeover switch is omitted for operators, and the over charging of the battery is avoided.
Abstract: The utility model relates to a device taking a generator driven by variable speed as a battery pack for charge, which comprises a magneto alternator, a main bridge type rectifier, an auxiliary bridge type rectifier, a storage battery, an electrical appliance, a sample circuit and a voltage-regulating circuit. The magneto alternator adopts a three-phase generator magneto alternator or a single-phase three-way magneto alternator. The utility model is used for automatically switching the states of charging and discharging the storage battery of the magneto alternator for keeping magnetism, the operation of wrenching a changeover switch is omitted for operators, and the over charging of the storage battery is avoided.

Patent
10 Oct 1991
TL;DR: In this paper, a method for sensing an applied magnetic field using a superconductor element with superconductive material as a sensor is presented. But the method is not suitable for the measurement of the superconducting material.
Abstract: A method for sensing an applied magnetic field uses a superconductor element with superconductive material as a sensor. The element is cooled to its superconducting state and current is supplied to the element. An applied magnetic field is applied to the superconducting material and an output from the superconductor element is fed to a feed back power source. In the feedback power source a comparison is made between an input voltage from the superconductive element and a reference voltage. Current is applied to a coil for applying a bias magnetic field to the superconductor element based on the comparison. With this method, the input voltage and the reference voltage are made as equal as possible. A superconductive device includes a coil for applying an AC power source and a coil for applying a DC power source. The DC power source can be set at various values and the application of the DC power source, which is a bias voltage, changes the output of the superconductive element by changing the electrical wave form outputted from the superconductive element.

Patent
15 Mar 1991
TL;DR: The magneto-resistive sensor as discussed by the authors comprises an elongated magneto resistive element (42) having an active region (48) for sensing information stored upon a magnetic storage medium (12) and having a wing region, first and second terminals (70, 72) applied to opposite ends (44, 46), and a capacitor (74) connected to the magnetoresistive element(42) for electrically shorting out AC signals generated by the first wing region.
Abstract: The magneto-resistive sensor comprises an elongated magneto-resistive element (42) having an active region (48) for sensing information stored upon a magnetic storage medium (12) and having a wing region, first and second terminals (70, 72) applied to opposite ends (44, 46) of the magneto-resistive element (42), and a capacitor (74) connected to the magneto-resistive element (42) for electrically shorting out AC signals generated by the first wing region of the magneto-resistive element (42).

Journal Article
TL;DR: In this paper, a Love-type magneto-surface-acoustic-wave (MSAW) transducers were constructed using amorphous FeB alloy films sputtered on glass substrates.
Abstract: We have constructed Love-type magneto-surface-acoustic-wave (MSAW) devices using amorphous FeB alloy films sputtered on glass substrates. For the Love-type SAW transducers, we employed interdigital electrodes combined with ZnO films rf-sputtered by oblique deposition, where the crystallographic c-axis of ZnO film is grown inclined to the substrate plane. The velocity controllability of a device using monolayer FeB film (operated at 72 MHz) is 1.03%. This controllability can be improved through the suppression of eddy-current accompanying MSAW propagation using multilayer FeB films alternately stacked with thin SiOx layers.

01 Jan 1991
TL;DR: In this paper, a finite element formulation, based on a direct solution of a system of dynamic, non-linear and coupled magneto-thermal equations, for ferromagnetic materials in induction heating devices is presented.
Abstract: This paper presents a finite element formulation, baaed on a direct solution of a system of dynamic, non-linear and coupled magneto-thermal equations, for ferromagnetic materials in induction heating devices. This formulation insures a real coupling between the equations. Thus, the results are more precise than those obtained from the classical modelling and the magneto-thermal problem simulations are faster and easier to perform.




Journal ArticleDOI
TL;DR: In this paper, the relationship between the size, shape and regularity of thermomagnetically written bits and the form of the hysteresis loop for TbFeCo thin films was investigated.

Journal ArticleDOI
TL;DR: The results of an investigation on the generation of higher harmonics under the passing of a low frequency current in HTSC ceramics by microwave spectroscopy methods are presented in this article.