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Showing papers on "Magneto published in 1981"


Journal ArticleDOI
TL;DR: In this paper, the application of a composite material as a magneto-electric transducer has been discussed and the results of the measurements on frequency response, transfer characteristics, internal impedance, temperature dependence and noise are discussed.
Abstract: This article deals with the application of a composite material as a magneto-electric transducer. The composite, which has both magneto-strictive and piezo-electric properties was developed at Philips' Research Laboratories. A transducer consisting of a piece of composite appears to be a suitable replacement for e.g. Hall devices, especially in AC applications. It needs only two electrical contacts and has a flat frequency response from a few Hz up to 650 kHz, where mechanical resonance occurs. Several calculations and experiments were carried out on the transducer and its electronic analogon, as well as on the measuring set-up, which had to produce a calibrated magnetic field. The results of the measurements on frequency response, transfer characteristics, internal impedance, temperature dependence and noise are discussed. The construction of a magnetic field probe using the composite is described and finally some other applications are given.

149 citations


Patent
22 Jan 1981
TL;DR: A magneto flywheel includes arcuate ceramic magnets of non-uniform radial thickness as mentioned in this paper, and a rotor for the flywheel is made of soft material, and the magnet of the fly wheel has a set of radial poles of alternating polarity, and an other set of opposite poles directed toward the cylindrical periphery of the magnet.
Abstract: A magneto flywheel includes arcuate ceramic magnets of non-uniform radial thickness. A rotor for the flywheel is made of soft material. The magnets of the magneto flywheel have a set of radial poles of alternating polarity, and an other set of opposite poles directed toward the cylindrical periphery of the magneto rotor. A ferromagnetic band of deflectible material with the surface projection is disposed between the rotor and the magnets.

28 citations


Patent
14 Apr 1981
TL;DR: In this paper, a magnetically-uniform magneto roll by a metod wherein a fixed magnetic field is applied externally so that an easy-to-magnetize axis of a magnetic material of a forming roll is oriented in the magnetic flux's direction passing through between magnetizing poles to form an anisotropic magneto rolling and then an inverse magnetic field to the magnetic field at formation is applied to degauss, following which remagnetization is conducted to obtain a specified magnetic intensity.
Abstract: PURPOSE:To produce a magnetically-uniform magneto roll by a metod wherein a fixed magnetic field is applied externally so that an easy-to-magnetize axis of a magnetic material of a forming roll is oriented in the magnetic flux's direction passing through between magnetizing poles to form an anisotropic magneto roll and then an inverse magnetic field to the magnetic field at formation is applied to degauss, following which remagnetization is conducted so that a specified magnetic intensity is obtained. CONSTITUTION:A resin magneto roll is formed with a composite comprising a ferrite powder including barium, strontium, lead, etc. or a rare earth elements magneto powder by 95wt%, a high-molecular comound of polyethylene, polystilene, etc. by 5-30wt%, a plasticizer by 0-10wt% and a lubricant by 0- 30wt%. In this forming work when the magnetic roll is extruded into a mold 7 composed of a non-magnetic region and a magnetic region to form it in a roll tube fashion, a magnetic field is externally applied by use of an electromagnet 13 at the same place as a pole to magnetized as a magnetic roll for a magnetic brush to generate a magnetic flux, and thereby an easy-to-magnetize axis of the magnetic powder included in resin which is under a fusion state is oriented in the direction of the magnetic flux.

15 citations



Journal ArticleDOI
TL;DR: In this paper, a theoretical explanation of the magnetic changes in electrical parameters (peak point voltage, valley point voltage and valley point current) of a unijunction transistor is proposed and compared with experimental results.
Abstract: A theoretical explanation of the magnetic changes in electrical parameters (peak point voltage, valley point voltage and valley point current) of a unijunction transistor is proposed and compared with experimental results.

7 citations



Patent
12 Jan 1981
TL;DR: In this article, the authors proposed to compensate a delay of ignition timing due to fluctuation of magnetic flux in accordance with a temperature rise, by connecting a thermo sensing element for detecting temperature of a magnet used in magneto to a gate circuit of a thyristor.
Abstract: PURPOSE:To compensate a delay of ignition timing due to fluctuation of magnetic flux in accordance with a temperature rise, by connecting a thermo sensing element for detecting temperature of a magnet used in magneto to a gate circuit of a thyristor. CONSTITUTION:A thermistor 16 with negative characteristics senses temperature of a magnet used in a magneto motor 1. As the magnet temperature rises, the output voltage of a condenser charging coil 1a drops. Since the resistance of the thermistor 16 also decreases due to the temperature rise, the voltage, applied from the condenser charging coil 1 to a gate cathode of a thyristor 2g and reduced under the influence of the magnetic flux of the magnet, is compensated to prevent any delay of ignition timing.

3 citations


Patent
24 Jul 1981
TL;DR: In this article, the authors proposed a method to take out a large power by a method wherein a small breaking magnet capable of interrupting the magnetic force and a balancing magnet arranged oppositely in the polarity are combined together.
Abstract: PURPOSE:To permit to take out a large power by a method wherein a small breaking magnet capable of interrupting the magnetic force and a balancing magnet arranged oppositely in the polarity are combined together. CONSTITUTION:A pair of large field magnets 1, 1' are arranged by two sets in parallel, two rotors 6, 6' polarized oppositely to each other are rotatably fitted through a same shift 7 corresponding to the field magnets, and a pair of small breaking magnets 2, 2' respectively disposed leaving a gap therebetween and balancing magnets 4, 4' respectively arrange symmetrically across the field magnets relative to the breaking magnets are mounted integratedly on both side ends of the respective rotors through combining implements 5, 5'. The small breaking magnets 2, 2' forming the individual combined breaking magnets 8, 8' change the polarity on the sides confronting each other to the same polarity as that of the rotors and field magnets on the other sides, and made the alternate entrance and exit of the individual combined breaking magnets setting to a rotation timing of the rotors, also by changing the polarity of the individual balancing magnets 4, 4' to the polarity opposite to that of the breaking magnets. Whereby the combined breaking magnets are moved enough by only a small power, so that the large power can be obtained from the shaft.

2 citations


Journal ArticleDOI
TL;DR: In this article, a model for the motion of a classical particle in a random array of scatterers is extended to discuss the effects of weak and intermediate magnetic fields, and it is shown that only the current relaxation kernel is the physical relevant one diverging at the percolation edge.
Abstract: A recently developed theory for the motion of a classical particle in a random array of scatterers is improved and extended to discuss the effects of weak and intermediate magnetic fields. By deriving expressions for the general relaxation kernels it is shown that only the current relaxation kernel is the physical relevant one diverging at the percolation edge. The percolation density and localization length turn out to be independent of the magnetic field. A negative magneto resistance at low scatterer density, a positive magneto resistance at larger density and a non classical Hall coefficient are obtained. For the velocity correlation spectrum a shift of the cyclotron resonance to higher frequency and a new low frequency side peak is predicted.

2 citations


Book ChapterDOI
31 Dec 1981

2 citations



Patent
27 Aug 1981
TL;DR: In this paper, a two-cycle engine provided with a magneto at one end of a crankshaft is mounted on a crankcase so that the coil section is located inside.
Abstract: PURPOSE:To increase the degree of freedom of design of an engine, by mounting a magneto base which supports a magneto coil section, on a crankcase so that the coil section is located inside. CONSTITUTION:In a two-cycle engine provided with a magneto at one end of a crankshaft 6, a magneto base 9 which supports the coil section 12 of the magneto is mounted on a crankcase 3 so that the coil section 12 is located inside. As a result, the thickness of the fitting portion 3a of the crankcase 3 for mounting the magneto base 9 can be made much larger than in the case that the fitting portion 3a would be located oppositely. For that reason, the meeting surfaces of the crankcase 3 and a cylinder 1 can be lowered for design requirement as the positions of a coil 10 and a rotor 7 remain unchanged.


Patent
18 Nov 1981
TL;DR: In this article, the backward voltage of the magneto is low, so that the voltage determined by voltage-dividing resistors RP1, RP2 is low and a thyristor TY does not conduct.
Abstract: PURPOSE:To obtain an advance characteristic by using a capacitor which is charged by a backward current of a magneto, in a magnetoelectric ignition device. CONSTITUTION:In low-speed rotation, the backward voltage of the magneto is low, so that the voltage determined by voltage-dividing resistors RP1, RP2 is low and a thyristor TY does not conduct. Therefore, the capacitor CA is not charged by the backward current. A forward current carses trasistors Q1, Q2 to conduct. When the voltage determined by resistors RM, RB3 is reached, a transistor Q3 is turned ON, whereby the transistors Q1 and Q2 are turned OFF to effect ignition. When the rotation frequency exceeds a predetermined value, the thyristor TY starts conducting, so that the capacitor CA is charged by the backward current and the corresponding voltage is applied to the transistor Q3, resulting in a corresponding advance of the ignition timing. Accordingly, the advance characteristic can be obtained in the magnetoelectric ignition device.

Patent
08 Jul 1981
TL;DR: Magneto inductance as mentioned in this paper is a type of magnetic inductance comprised of a coil having a small number of turns on one or several thin strips (2, 4, 5) insulated between each other, combined to an oscillatory electronic device of which the frequency is proportional to the incident magnetic field.
Abstract: not available for EP0031322Abstract of corresponding document: WO8100170Magneto-inductance comprised of a coil (1) having a small number of turns on one or several thin strips (2, 4, 5) insulated between each other, of a high magnetic permeability alloy, combined to an oscillatory electronic device of which the frequency is proportional to the incident magnetic field.