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村重 伸一, 小林 洋志, 河口 栄二, 斉藤 皓彦
1996 年 20 巻 2 号 p.
453-456
発行日: 1996/04/01
公開日: 2007/10/24
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The effect of tensile stress on the magnetization properties of grain oriented silicon steel sheets cut at a declining angle of nearly 90° from the rolling direction was investigated. The region occupied by the magnetic field for a sample with initial low permeability decreases as a result of a low tensile stress, but increases as a result of a high tensile stress. The inflection point can be detected at the end of this region on the magnetization curve. The value of the magnetic field at the inflection point can be calculated by considering both the magnetoelastic energy and the magnetostatic energy.
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斉藤 皓彦, 山崎 隆弘, 菅原 孝幸, 村重 伸一
1996 年 20 巻 2 号 p.
457-460
発行日: 1996/04/01
公開日: 2007/10/24
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The effects of tensile stress and heat treatment on the magnetization properties of an amorphous ribbon with negative magnetostriction constant are investigated. The stress-magnetization curve under a constant magnetic field shows peculiar characteristics at the point of residual magnetization and when the magnetic field is weak. The locus of the magnetization change due to tensile stress is quite different from that obtained previously by us. The properties of reversible and irreversible magnetization change are also investigated.
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李 衛東, 北上 修, 島田 寛, 石山 和志, 荒井 賢一
1996 年 20 巻 2 号 p.
461-464
発行日: 1996/04/01
公開日: 2007/10/24
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Fe-Al-O films with a nano-granular structure were fabricated by RF magnetron sputtering. The films exhibit good magnetic softness together with high electrical resistivity.However, they have relatively large deterioration of the initial permeability at high frequencies. In an attempt to explain this peculiar behavior, dispersion of magnetic anisotropy in the films was measured by biaxial Vibrating Sample Magnetometer (VSM), but a theoretical calculation taking account of this anisotropy dispersion resulted in poor agreement with the experiments. Other possibilities such as the existence of a weak ferromagnetic phase, which may dominate the initial permeability, or strong damping of the spin precession, which may occur in the nanogranular structure, were also investigated, but none explained the peculiar behavior of the permeability. The results of this investigation suggest that the dielectric property of the granular film should be studied as a possible cause of this peculiar behavior.
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M. Kadono, 藤根 俊之, 村松 哲郎
1996 年 20 巻 2 号 p.
465-468
発行日: 1996/04/01
公開日: 2007/10/24
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Sendust films with (111) orientation were studied on underlying iron films deposited by the N
2 DC plasma evaporation method.The orientation of the Sendust films was found to depend on the grain size and resistance of the underlying iron films.As a result of both the deposition rate and substrate temperature being controlled during iron deposition, the grain size became smaller and resistance became higher than those of iron films deposited in a vacuum.Sendust films with (111) orientation deposited on the above underlying iron films showed good softness appeared and a magnetic permeability of about 10000.
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小林 伸聖, 大沼 繁弘, 藤森 啓安, 増本 健
1996 年 20 巻 2 号 p.
469-472
発行日: 1996/04/01
公開日: 2007/10/24
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The magnetic properties and electrical resistivity of Fe-X-O (X=Y, Nd, Sm, Gd, Tb, Dy) films were investigated.The films were prepared by co-sputtering of Fe and X
2O
3 targets in a static magnetic field. They seem to have a granular type of structure composed of magnetic grains with a diameter well under 100Å and thin oxide boundaries with high electrical resistivity. The films have soft magnetic properties, as well as high electrical resistivities of more than 250μΩ cm, a maximum magnetic anisotropy field of 31.9 Oe, and saturation induction of about 13 kG in the as-deposited state. They also have a good frequency response of permeability. These results are attributed to the eddy current loss reduction caused by the films' high electrical resistivities, and to the higher natural resonance frequency caused by the high magnetic anisotropy fields and magnetic induction.
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小林 伸聖, 大沼 繁弘, 藤森 啓安, 増本 健
1996 年 20 巻 2 号 p.
473-476
発行日: 1996/04/01
公開日: 2007/10/24
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The magnetic properties of Fe-X-TM-O (X=Y, Nd, Sm,Gd, Tb, Dy: TM=Ni, Pd. Pt) films with a high electrical resistivity prepared by the co-sputtering of Fe, X
2O
3, and TM targets ate repoted. A uniaxial magnetic anisotropy was induced in these films during deposition in a static magnetic field. Fe
46.2Y
9.1Pt
14.9O
29.8 film has a magnetic anisotropy field (
Hk) of 52.4 Oe. The film has a good frequency resonance of the permeability up to 500 MHz. The results are attributed to the reduction of eddy current loss resulting from the films' high electrical resistivities and to the higher natural resonance frequency resulting from their high
Hk and magnetic induction.
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藤本 慎一, 佐藤 文隆, 宮崎 照宣
1996 年 20 巻 2 号 p.
477-480
発行日: 1996/04/01
公開日: 2007/10/24
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The influence of the crystal structure (fcc and bcc phases)and preferred orientation on the high-frequency permeability and magnetostriction was investigated for Co-rich Fe-Co-Ni ternary alloy films near the composition of the λ
s=0 line for bulk samples. Samples with a higher content of fcc phase and (111) preferred orientation exhibited a higher permeability between 1000 and 2000. The best soft magnetic properties examined for Fe
26Co
50Ni
24 film are μ' = 2100(at 10 MHz),
Hc= 1.3 Oe,
Bs= 17.5 kG, λ
s= 11 × 10
-6, and
ρ =18μΩ·cm. It was found that the phase boundary between the fcc and bcc phases in the films shifted toward the Ni-rich composition side by about 10% from the position for bulk samples.
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佐藤 文隆, 宮崎 照宣
1996 年 20 巻 2 号 p.
481-484
発行日: 1996/04/01
公開日: 2007/10/24
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Sputtered Fe, Fe
97.5Ti
2.5Fe
97.5-xCo
2.5Ti
x (2.5≤
x ≤ 10) films in a mixed Ar and N
2 gas atmosphere were studied in order to determine the dependence of their soft magnetic properties on the N
2/(Ar+N
2) flow ratio and composition.After annealing at 573 K for 1 h, the permeabilities of Fe
97.5Ti
2.5 and Fe
87.5Co
2.5Ti
10 films were more than 1000, while the corresponding saturation magnetic flux density was about 20 kG. The permeability change in with the N
2/(Ar+N
2) flow ratio is discussed in relation to the grain size and lattice strain.
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配島 俊一, 三木 剛, 伊藤 友幸, 阿部 正紀
1996 年 20 巻 2 号 p.
485-487
発行日: 1996/04/01
公開日: 2007/10/24
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Polycrystalline films of Mn
xZn
yFe
3-x-yO
4 with a spine1 structure were synthesized from a highly alkaline (pH=13) aqueous solution containing FeC1
3, MnC1
2, ZnC1
2, and KNaC
4H
4O
6(R ochelle salt). The metal ions, Fe
3+,M n
2+,and Zn
2+, were chelated with Rochelle salt, which prevented them from being precipitated in the high pH region. The solubility limit,
x, of the Mn ions was much higher (reaching up to 1.5) than that (
x≤∼0.12) obtained in conventional ferrite plating by using a neutral (pH∼7) aqueous solution.On the other hand, the solubility of the Zn ions was lower than that obtained by using a neutral aqueous solution.
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大沼 繁弘, 三谷 誠司, 藤森 啓安, 増本 健
1996 年 20 巻 2 号 p.
489-492
発行日: 1996/04/01
公開日: 2007/10/24
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A study was made of the structure and properties of Co-Al-O-based films prepared by RF magnetron reactive sputtering using oxygen and argon gases. Among Co-O-based films, only those with Al show soft magnetic properties.The Co-Al-O-based films have an electrical resistivity of about 1000μΩcm, a magnetic anisotropy field of about 80 Oe, and magnetic induction of about 10 kG. As a result they exhibit a remarkable frequency response of the permeability up to around 500 MHz. TEM observaion revealed that soft magnetic Co-Al-O films have a granular structure, where the grain is finer than 5 nm in diameter and the intergrain is extremely thin. The soft magnetic properties of these films are strongly related to their structure, which is attributed to the difference in heat of formation (
viz. binding energy) between Co-O and Al-O.
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石山 和志, 豊田 明久, 荒井 賢一
1996 年 20 巻 2 号 p.
493-496
発行日: 1996/04/01
公開日: 2007/10/24
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We used bi-axial VSM to evaluate the anisotropy dispersion of a rotational-field-annealed CoZrNb thin film that shows an almost isotropic
M-H curve. It was demonstrated that the isotropic properties of this film resulted from wideangle dispersion of the anisotropy. Using the measured
Hk of the film, we calculated the frequency dependence of the permeability, and found that the calculated value agrees well with the measured one. We also calculated the magnetic torque curve, using the measured magnetic anisotropy dispersion of a CuMo-permalloy film. The calculated curve also agrees well with the measured curve.
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皆川 保, 佐藤 直義, 野村 武史
1996 年 20 巻 2 号 p.
497-500
発行日: 1996/04/01
公開日: 2007/10/24
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The effect of SnO
2 addition on the loss characteristics of MnZn ferrites for use at 100 to 200 kHz was studied with special reference to the factors for core loss. Superior loss characteristics of 199 kW/m
3 at 80°C, 100 kHz, and 200 mT, were achieved by SnO2 addition. The core loss at 100 kHz consists of hysteresis and eddy current losses. Addition of SnO
2 is effective in reducing both hysteresis and eddy current losses. This improvement can be correlated with a uniformly sized grain microstructure and high resistivity of the grain boundaries.
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中野 貴弘, 佐藤 直義, 野村 武史
1996 年 20 巻 2 号 p.
501-504
発行日: 1996/04/01
公開日: 2007/10/24
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To improve the core loss of MnZn ferrite at high frequencies,the loss characteristics were investigated. For a core with fine grains sintered at a low temperature, high density was obtained and the rapid increase in the loss factor at high frequencies was reduced. Numerical analysis was performed to divide the core loss into the hysteresis loss,the eddy current loss, the dielectric loss, and the residual loss. The residual loss was dominant at higher frequencies and decreased more for the core with a smaller grain size.
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佐藤 陽一, 藤倉 昌浩, 芳賀 由美子, 佐藤 駿
1996 年 20 巻 2 号 p.
505-508
発行日: 1996/04/01
公開日: 2007/10/24
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An Fe-based amorphous/nanocrystalline bilayer ribbon was prepared by rapid quenching and subsequent annealing. The
B-H loop exhibited a high permeability at low field and a slow approach to saturation, quite unlike the two-step
B-H loop of lap-wound individual amorphous and nanocrystalline monolayer ribbons. This result for bilayered ribbon indicates the occurrence of magnetomechanical interaction due to interlayer stresses induced on annealing to the point of nanocrystallization.
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石橋 新一郎, 佐藤 寿彦, 羽田 絋一, 加藤 喜弘
1996 年 20 巻 2 号 p.
509-512
発行日: 1996/04/01
公開日: 2007/10/24
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Boilers are used for heating various places, from small buildings to thermal power plants. Scaly material from a water solution in boiler sludge is sometimes precipitated, disturbing the flow of steam and decreasing the thermal efficiency. In this study, we report on ferric substances in boilers used for heating buildings. These ferromagnetic materials (Fe
3O
4) constitute approximately 20% to 25% of all substances, and have ultrafine particulars with an average size of 17-27 nm. The saturation magnetization is 65-77 emu/g when corrected for the presence of calcite and a non-magnetic layer on the particle surface. This value is almost the same as for bulk Fe
3O
4. In order to remove substance from inside the boiler, we normally stop operating the boiler and wash it with antiscale reagents. Bacause of the presence of the ferromagnetic substance, we tried to install a bypass in the pipe and attached a magnet outside, allowing the substances to be removed from the boiler system by applying a magnetic field.
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廣田 憲之, 本間 琢朗, 崎浜 竜也, 酒井 正格, 菅原 宏治, 北沢 宏一, 岩坂 正和, 上野 照剛, 横井 裕之, 角舘 洋三, ...
1996 年 20 巻 2 号 p.
513-516
発行日: 1996/04/01
公開日: 2007/10/24
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The effect of a magnetic field on the interface profile between two non-magnetic liquids, aqueous solutions, and/ or organic liquids (the enhanced Moses effect) was investigated. The observed interface profile is well explained quantitatively by an equation that was derived to minimize the sum of the gravitational potential energy and the magnetic energy. In considering this, it will be seen that the magnitude of the magnetic field effect on the interface profile can be enhanced by preparing two liquids whose densities are very close. This "enhanced Moses effect" is demonstrated practically by using a permanent magnet.
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光武 義雄, 平田 勝弘, 石原 好之
1996 年 20 巻 2 号 p.
517-520
発行日: 1996/04/01
公開日: 2007/10/24
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This paper proposes a computational method for predicting the dynamic response characteristics of a long-stroke(7 mm) linear electromagnetic solenoid with an armature of complicated shape. In this method, the magnetic field is completely coupled with the electrical supply and the mechanical movement of the actuator, employing the axisymmetric finite element method (FEM). The utility of this method is verified by comparing the computed results with the measured results.
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佐藤 文博, 村上 純一, 松木 英敏, 菊池 新喜
1996 年 20 巻 2 号 p.
521-524
発行日: 1996/04/01
公開日: 2007/10/24
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We propose a contactless power transmission system using meander coils that allows coil displacement and is easy to manufacture. Uses of the system will include power supply to microcomputers, portable household electric appliances,and battery charging systems, and may also include transmitting larger amounts of power. We studied how to increase the transmitted power, the relation between the induced voltage and the gap between coils, and the geometry of the receiver coil.
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藤原 徹, 瀬戸 学雄, 小川 浩史, 加賀 美金雄
1996 年 20 巻 2 号 p.
525-528
発行日: 1996/04/01
公開日: 2007/10/24
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To study the relationship of the winding resistance at high frequencies to the thickness of copper foils, we built a planar transformer for switching power supplies, using a multilayer printed wiring board. As a result, the optimal thickness of copper foils,
t0, which provides the least copper loss, was experimentally shown. Moreover, we compared the experimental values with the calculated values, using a simplified analysis based on the assumption that the magnetic flux in the core window is parallel to the base of the core. For
t0, the experimental values were found to agree satisfactorily with the calculated values. This method may therefore be effective for designing thin multilayer planar transformers.
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藪上 信, 渡辺 光春, 山口 正洋, 荒井 賢一
1996 年 20 巻 2 号 p.
529-532
発行日: 1996/04/01
公開日: 2007/10/24
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A configuration of microstrip-line-type coils was developed for measuring electromagnetic noise. The measurement system consists of a microstrip-line-type coil array,diode switch circuits, an amplifier, and a spectrum analyzer.Some measurements of noise from a personal computer obtained by means of this system are presented.
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水野 勉, 安西 哲也, 山田 一
1996 年 20 巻 2 号 p.
533-536
発行日: 1996/04/01
公開日: 2007/10/24
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A high-speed hydraulic servo valve using a linear dc motor (LDM), which has the LDM's yoke made of a carbon steel (S 15C), has been developed by the authors. To simplify the manufacturing process for the LDM's yoke, the use of spheroidal graphite cast iron (FCD450) is considered. This paper describes the dc and ac magnetization characteristics of S15C and FCD450, and the static and kinetic characteristics of two LDMs made of S15C and FCD450, respectively.The following conclusions are reached: (1) the maximum magnetic flux densities of S15C and FCD450 at a magnetizing field of 5 kA/m are 1.63 T and 1.31 T, respectively, (2)the maximum static thrusts of two LDMs made of these materials a t an exciting current of 7 A are 91 N and 82 N.respectively, and (3) the frequency response of two LDMs made of these materials are 420 Hz and 370 Hz, respectively.
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本田 崇, 荒井 賢一
1996 年 20 巻 2 号 p.
537-540
発行日: 1996/04/01
公開日: 2007/10/24
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This paper presents a new type of wireless walking micro-mechanism based on magnetostrictive vibration. A 16-mm-long trial walking mechanism, composed of a magnetostrictive thin-film bimorph and two inclined legs, was fabricated. It showed a high velocity of the order of cm/s and a reversible motion, with forward and backward directions. The actuation of the legs was analyzed by using a simple model. The calculated velocity agreed with the experimental results.
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本田 崇, 島崎 克彦, 荒井 賢一
1996 年 20 巻 2 号 p.
541-544
発行日: 1996/04/01
公開日: 2007/10/24
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This paper proposes two kinds of swimming micromechanisms with low Reynolds numbers. One is a fin-type mechanism, which is composed of a cylinder magnet and an elastic fin. The other is a spiral-type mechanism, which is composed of a cubic magnet and a spiral wire. Both mechanisms are remotely operated by magnetic torque in an alternating magnetic field. The fin-type mechanism generates a bending wave that passes along the fin, allowing the mechanism to swim in one direction. The spiral-type mechanism generates a spiral wave, and can swim both forward and backward.
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鶴本 勝夫, 今村 元紀
1996 年 20 巻 2 号 p.
545-548
発行日: 1996/04/01
公開日: 2007/10/24
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A magnetic gear using a permanent magnet has many advantageous performance characteristics, such as absorption of vibration, noiselessness and oilless operation. Further, a magnetic gear designed as an internal meshing gear can be used as an external meshing gear by changing the center distance.
This paper is explains the mechanism whereby a magnetic force arises in a meshing area composed of a main contact zone and an intersecting zone when the gear is changed from internal meshing to external meshing.
It is found that the composition of the magnetic flux density and polarity distribution, namely, "the magnetic tooth", is useful for investigating the mechanism whereby the magnetic force arises. The magnetic force is decreased by about 10-30% when the gear is changed from internal meshing to external meshing; this causes no problems in practical use.
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増田 純夫, 小松 健作, 竹村 泰司, 山田 努, 角野 圭一
1996 年 20 巻 2 号 p.
549-552
発行日: 1996/04/01
公開日: 2007/10/24
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This paper shows that magnetoelastic waves propagating through an Fe-Si-B amorphous wire and ac currents passing through the same wire can be detected independently by a single pick-up coil. The detection efficiency is measured as a function of the bias field applied to the wire. The paper also describes a technique for observing dynamic magnetization processes in an amorphous wire magnetized by an ac current passing through it. The pick-up coil detects an electromotive force induced by the longitudinal component of magnetization vector. The circumferential component of the vector induces another electromotive force between the ends of the wire. Simultaneous observation and integration of these electromotive forces shows the two-dimensional behavior of the magnetization in the wire.
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森川 健志, 西部 祐司, 山寺 秀哉, 野々村 裕, 竹内 正治, 多賀 康訓
1996 年 20 巻 2 号 p.
553-556
発行日: 1996/04/01
公開日: 2007/10/24
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A very large magneto-impedance (MI) effect was found in CoSiB/Cu/CoSiB and FeCoSiB/Cu/FeCoSiB elements fabricated by the RF magnetron sputtering method. The Cu layer was covered with amorphous magnetic layers and most of the ac current was applied in the Cu layer. An easy axis was added in the transverse direction, perpendicular to the ac current, of the magnetic layers. As a result, when an external magnetic field was applied in the longitudinal direction, very large impedance change ratios were achieved, such as 330%/9 Oe at 10 MHz and 120%/9 Oe at 1 MHz. These ratios are larger by three orders of magnitude than those of a single-layered element.
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竹村 泰司, 増田 純夫, 中出 伸二, 山田 努, 角野 圭一
1996 年 20 巻 2 号 p.
557-560
発行日: 1996/04/01
公開日: 2007/10/24
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A large magnetostriction in FeSiB realizes strong magnetoelastic coupling, and allows efficient driving and pickup of magnetoelastic waves. Owing to the high electrical resistivity of amorphous FeSiB, the eddy current loss of the propagated magnetoelastic waves is low. Only a longitudinal mode of the waves is propagated in the onedimensional shape of the wires. Because of these characteristics, the attenuation constant of the waves is low (0.18 m
-1 at 500 kHz), and they are propagated over a long distance. As an application of the waves, a long-range position sensor was fabricated. The output signal, whose period is proportional to the sensing distance, was obtained for the detection range from 0 to 5.0 m.:with an resolution of 1 mm. The analyses of the reflection factor of the magnetoelastic waves and reflecting methods for the sensor are discussed. A high reflection factor was obtained by successfully using a wheel-type reflector in the sensor.
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務中 達也, 吉見 健一, 中西 博昭, 飯島 健二, 山田 康晴
1996 年 20 巻 2 号 p.
561-564
発行日: 1996/04/01
公開日: 2007/10/24
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We fabricated a thin-film ring-core fluxgate sensor, using photofabrication techniques. The sensor consists of a perm- alloy ring-core, an excitation coil, and a differential pick-up coil. The two coils are wound round the core. The core is 4.24 mm in diameter, 160μm in width, and 1.5,μm in thick- ness. When the sensor is operated in a feedbackloop, the magnetic sensitivity is about 0.42 V/μT at an excitation frequency of 500 kHz, and a noise level of 1 nT/√Hz is estimated at 25°C and 100 Hz. This magnetometer system has good linearity for a magnetic field in the range from -26μT to 26μT. The magnetic sensitivity and the fluctuation of the zero point are independent of the tempera- ture in the range from -20°C to 65°C.
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長田 洋, 安宍 善史, 菊池 孝, 田山 典男, 関 享士郎, 菊地 新喜
1996 年 20 巻 2 号 p.
565-568
発行日: 1996/04/01
公開日: 2007/10/24
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Temperature-sensitive magnetic cores and thick films have previously been fabricated for thermal sensors. These magnetic substances are suitable for large instruments, but cannot be adapted for miniaturization. A emperaturesensitive magnetic thin-film sensor (MFS) was made by sputtering and annealing a Mn-Zn ferrite magnetic core with low-Curie-temperature. The thickness ranged from 0.8 to 1.2μm. Magnetic properties were acquired by means of an annealing process. The magnetic characteristics of the MFS have a marked temperature dependence, like those of a bulk core or a thick-film. The magnetization at 10°C is 30% of that at 50°C. The MFS has a quick thermal response and can be used as a micro-temperature sensor, a thermomagnetic transducer, and a light-magnetic converter.
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加藤 亮太, 卜 慶華, 島田 武志, 岸本 哲, 竹下 邦夫, 山田 一
1996 年 20 巻 2 号 p.
569-572
発行日: 1996/04/01
公開日: 2007/10/24
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An eddy current sensor can be used as a device for detecting anomalous objects, such as shovels and jacks, lying on a railway line. Such an object is called a target in this paper, which investigates the dependence of the basic characteristics of an eddy current sensor on the area of the target. The following conclusions are derived. First, the dependence of the inductance,
ΔLβ, on the target/coil area, β, can be approximated by an exponential function in some coils with different radius. Second, when lift-off/coil radius γ= 1 the change in the inductance,
ΔLβ/
L0, is 1%, where
L0 is the coil inductance without the target.
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笹田 一郎, 渡邊 直幸
1996 年 20 巻 2 号 p.
573-576
発行日: 1996/04/01
公開日: 2007/10/24
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A new magnetic bar code system is proposed, in which information is coded in a series of anisotropic perrneabilities introduced by, for example, slightly canted magnetic strips. The principal direction of anisotropy with respect to a given direction as a reference can be coded as 1 or 0. This principal direction is detected inductively by using crosscoupled figure-of-eight coils, in which the sign of the mutual inductance changes according to the sign of the angle between the principal direction and the given direction. The readout is not affected by the scanning speed in this system.
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加藤 正樹, 山田 外史, 岩原 正吉
1996 年 20 巻 2 号 p.
577-580
発行日: 1996/04/01
公開日: 2007/10/24
ジャーナル
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This paper describes the detective characteristics of a planar-type eddy-current testing (ECT) probe for use in advanced ECT technology. The probe has a sandwich structure of meander and mesh coils. The key operation depends on the patterns of both meander and mesh coils for high-frequency excitation and sensing. The particular functions of the probe are the detection of (1)crack size and (2) its direction on the conducting plate. Experimental results confirm that the probe has detective characteristics, and sufficient sensitivity to detect cracks.
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脇若 弘之, 栗山 保, 辻 弘伸, 坂田 文男, 山崎 宣悦, 山田 一
1996 年 20 巻 2 号 p.
581-584
発行日: 1996/04/01
公開日: 2007/10/24
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Magnetic signal transmission (MST) is an effective method for transmitting information underground by radio to allow efficient drilling work. This paper shows that the transmission media of MST are an electromagnetic wave and a domain wall. Experiments showed that the propagation time for MST signals becomes longer as the distance between the transmitting and receiving coils increases. The propagation time for magnetic signals is also affected by the rod material, the frequency, and the current. MST signals have a velocity of 2653.4 [m/s] when ƒ=200 [Hz],
It=0.25 [A], χ= 1 [m] and the rod material is SPCC. The cause of the variance of the propagation time of MST signals was confirmed by impulse response.
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田中 幸雄, 原田 和郎, 石原 好之, 戸高 敏之, 平田 勝弘
1996 年 20 巻 2 号 p.
585-588
発行日: 1996/04/01
公開日: 2007/10/24
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This study describes the dynamic response analysis of a magnetically levitated drilling machine under feedback control.
This machine is used for boring small holes in printed circuit boards with highly accurate positioning and sizing, and is operated under feedback control as follows. The exciting currents are increased or decreased according to information (the displacement and velocity of the levitated table), provided by gap sensors.
To obtain the optimum conditions for feedback control, dynamic analysis is carried out by using the finite element method combined with the equation of motion and the control equation. As a result, the effect of the control constant on the recovery time of the levitated table is defined.
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藪上 信, 渡辺 光春, 菊池 弘昭, 山口 正洋, 荒井 賢一
1996 年 20 巻 2 号 p.
589-593
発行日: 1996/04/01
公開日: 2007/10/24
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We developed a new thin-film permeance meter that is effective from 10 MHz to 1.5 GHz, using a microstrip pickup coil that senses the change in flux in a film sample driven in the TEM propagation mode. The microstrip pickup coil allows broader-band measurement of the permeance than a figure-8-coil, because impedance matching is provided. The influences of the exciting electric fields and the higher-order mode in the driving coil on the permeance measurement are analyzed. A strong de field (170 Oe) is applied parallel to the easy axis during the reference voltage measurement in order to eliminate the influence of the electric field.
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脇若 弘之, 妹尾 伸一, 矢島 久志, 織田 順平, 山田 一
1996 年 20 巻 2 号 p.
593-596
発行日: 1996/04/01
公開日: 2007/10/24
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A linear de motor (LDM) with an excellent high-speed response was designed and studied by magnetic field analysis using the finite element method (FEM). In a thin type of determined LDM, the thickness of the yoke on a unipolar- type LDM was selected according to the magnetic saturation. In a multipolar-type LDM, on the other hand, the magnetic flux density in the gap could be increased, and in this case the magnetic attraction force also increased. The thickness of the yoke was therefore selected according to the mechanical strength of the yoke in relation to the magnetic attraction. Thus, the yoke of a LDM was assumed to be a simple beam which a uniform by distributed load was applied. The limit of the LDM thickness was calculated from the bend of the yoke. For a stroke of 112 [mm], the LDM was designed to have a yoke with a thickness of 5.7 [mm] and permanent magnet with a thickness of 1.2 [mm].
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石川 和己, 川上 峰夫, 菊池 新喜
1996 年 20 巻 2 号 p.
597-600
発行日: 1996/04/01
公開日: 2007/10/24
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A double-sided linear parametric motor has a simple construction and is easy to maintain. It consists of two four-legged laminated linear parametric motors. A useful method for improving the characteristics of a double-sided linear parametric motor is to connect the excited windings. We call the connections
MD1 and
MD2, both of which increase the air-gap flux density, tuning capacitor enlargements. The phase difference of φ
1 and φ
2, which are the fluxes of motors 1 and 2, is in-phase and anti-phase for connections
MD1 and
MD2, respectively. The connection
MD1 greatly increased the static thrust-force and the thrust- force to input power ratio of the linear parametric motor.
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山田 一, 高野 豊, 八重崎 昌治, 松本 好司, 西澤 尚武, 岩崎 博行, 穂谷 敏幸
1996 年 20 巻 2 号 p.
601-604
発行日: 1996/04/01
公開日: 2007/10/24
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A conventional milking machine may damage cows'teats, because the suction mechanism is driven by a pneumatic pulsator at a constant frequency. It is known that in natural feeding of calves, a l/
f fluctuation signal occurs. This paper describes the performence of a new linear pulsator used instead of a pneumatic pulsator in a milking machine.The linear pulsator is drivenby a cylindrical linear oscillatory actuator (LOA) that is compact and weight light, with external dimensions of
φ25 × 35mm, a mass of 114 grams,and a maximum static thrust of 8.2 newtons. It can drive a real load at a frequency of 1 Hz and a voltageof 14 volts, with a stroke of ±2mm. The linear pulsator that contains the LOA is capable of operating with a I/
f fluctuation signal, and can realize pressure pulsation a ranging from 41 to 71 beats per minute.
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脇若 弘之, 降幡 大作, 中村 文彦, 鎌田 弘志, 吉川 隆, 山田 一
1996 年 20 巻 2 号 p.
605-608
発行日: 1996/04/01
公開日: 2007/10/24
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A vibration element using giant magnetostrictive material (VEG) was developed as of a unit of an acoustic source for an ocean acoustic tomography system. This acoustic source was required to have low frequency and high power output. The magnetostriction characteristics of the giant magnetostrictive material were greatly altered by prestress. A VEG with changeable prestress was constructed, and its characteristics were measured for various values of prestress. This paper describes the effects prestress and changes in the magnetomechanical coupling factor on the operation of the VEG. Measurement of the static magnetostriction and impedance characteristics of the VEG showed that there were optimum values of the prestress and magnetic bias of the operating point on the static magnetostriction characteristics. Correlation between static magnetostriction and magnetomechanical coupling factor was indicated.
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菊池 良巳, 中村 文彦, 脇若 弘之, 山本 行雄, 山田 一
1996 年 20 巻 2 号 p.
609-612
発行日: 1996/04/01
公開日: 2007/10/24
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A magnetic encoder has a simple structure and is strong in dirt. In the field of factory automation, many magnetic rotary encoders are therefore used in a servo motor to detect the angle and speed of rotation. This paper investigates the distortion wave of the output voltage in the magnetic encoder, and also discusses the distortion factor range of less than 10 percent. It is established that the output voltage takes the maximum value, that the cause of the distortion wave is the saturation of the magnetic char- acteristic of the MR element, and that the range of the distortion factor less than 10 percent spreads out in a belt under a magnetic field of 300 mA.
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山口 正洋, 吉田 周作, 荒井 賢一, 芳賀 昭
1996 年 20 巻 2 号 p.
613-616
発行日: 1996/04/01
公開日: 2007/10/24
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We measured the permeance of Cu-Mo-Ni-Fe film and Co-Zr-Nb film up to 5 Oe and up to 10 MHz along the hard and easy axes of magnetization, using the figure-of-eight coil method, with a new three-turn separated type of Helmholtz coil. The permeance of Cu-Mo-Ni-Fe film and Co-ZrNb film along the hard axis of magnetization changed when the amplitude of the magnetic field exceeded the anisotropy field of each film. The permeance along the easy axis of magnetization depended on the kind of film. The perrneance of Cu-Mo-Ni-Fe film along the easy axis of magnetization changed when the amplitude of the magnetic field exceeded the corresponding ac coercive force.
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山田 一, 小林 学, 渡辺 充昭, 水野 浩司, 山口 昌樹
1996 年 20 巻 2 号 p.
617-620
発行日: 1996/04/01
公開日: 2007/10/24
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A linear pulse motor (LPM) was developed as the actuator for a total artificial heart (TAH). In general, the kinetic thrust of the LPM decreases gradually following as the mover velocity increases. This paper presents the following approximate expression for the kinetic thrust,
Fk of the LPM:
Fk=
kFsm{1-C(
v⁄
vm)²}[N],
| where | k | is the structure factor of the LPM, |
| Fsm | is the maximum static thrust [N], |
| C | is a factor due to the magnetic material, and |
| vm | is the maximum valocity [m/s]. |
The physical meanings of the factors
k and
C in the above expression are also discussed.
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曽根 威之, 安藤 誠吾, 毛利 佳年雄
1996 年 20 巻 2 号 p.
621-624
発行日: 1996/04/01
公開日: 2007/10/24
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Two highly sensitive magnet-displacement sensors with a resonant-multivibrator and a Colpitts oscillator, respectively,were constructed by using amorphous wire magnetoimpedance elements. The sensor output is independent of the magnetic pole sign on account of the magnetoimpedance characteristics, which allow highly operable measurement of eyelid motions such as blinks. Small magnets were attached to the eyelids of several subjects, and the movements of the magnets when the subjects blinked were detected by the sensor. Sleepiness was clearly estimated by measuring the length of time that the eyelids were closed during blinking, the results were independent of subjects.
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L. V. Panina, T. Kitoh, M. Noda, K. Mohri
1996 年 20 巻 2 号 p.
625-628
発行日: 1996/04/01
公開日: 2007/10/24
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The magneto-impedance (MI) effect in a twisted Co- based amorphous wire magnetized with a short pulse current has a bistable character: the induced wire voltage jumps at certain critical fields and exhibits a sharp hysteresis. This paper analyses the basic properties of the bistable M1 effect on the basis of a hysteresis in the ac rotational permeability in the case of a helical anisotropy typical of a twisted wire. The proposed model satisfactorily describes the experimental results. The bistable M1 element, which can be shortened to 0.5 mm in length, can be used in micro-sized switch-type field sensors such as sensitive proximity sensors. It also has a potential for application in a digital magnetic memory cell of nondestructive readout for a neural network memory.
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武士田 健一, 毛利 佳年雄
1996 年 20 巻 2 号 p.
629-632
発行日: 1996/04/01
公開日: 2007/10/24
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A new high-performance micro-current sensor with circular amorphous wire magneto-impedance (MI) element installed in a Colpitts oscillator is presented. A zeromagnetostrictive amorphous wire ((Fe
0.06Co
0.94)
72.5 Si
12.5B
15, λ
s = -10
-7) was used to make a circular head with a 10 mm diameter set around a conductor. The current sensor is of the amplitude modulation-demodulation type with a strong negative feedback loop. It has a sensing performance of a high linearity (a non-linearity of less than 0.5%FS (± 1.5 A)), quick response with a cur-off frequency of about 1 MHz due to a high oscillation frequency of 30 MHz, and a high sensitivity of about ±10μA(ƒ=1kHz). This sensor works stably in uniform-distrubance magnetic field such as the terrestrial magnetic field (≅0.3 Oe), because of the cancelling in the circular MI head.
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海老根 典也, 竹内 信次郎, 荒 克之
1996 年 20 巻 2 号 p.
633-636
発行日: 1996/04/01
公開日: 2007/10/24
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Eddy-current nondestructive testing was conducted by using detecting magnetic flux distorted by flaws using a new type of parallelogram probe that was developed to detect flaws independently of their directions. The probe is composed of differential magnetic flux pick-up coils and parallelogram exciting coils. Detection characterics were invesigated with respect to the exciting frequencies and flaw shapes. The obtained results showed that both horizontal and vertical slit-flaws can be detected successfully. Outer surface laws that is in the outer surface of an luminum test plate with a thickness of 1mm can be detected at an exciting frequency of 20 kHz, and inner surface flaws at 200 kHz.
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