• Title/Summary/Keyword: hall effect

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A Study on InSb Magnetic Sensor using Hall Effect (Hall효과를 이용한 InSb가 자기 Sensor에 관한 연구)

  • Jeon, Chun-Saeng
    • Korean Journal of Materials Research
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    • v.4 no.1
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    • pp.113-116
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    • 1994
  • InSb thin film magnetic sensor, which have been prepared on glass substrate by vacuum evaporation, is investigated in this paper. The dependance of Hall voltage on magnetic field and temperature is examined by Hall effect. The variation of Hall voltage with magnetic field is almost linear at constant current drive but it is deviated from the linearity at constant voltage drive. Hall voltage decreases as the ambient temperature increases, so it is necessary to take into account the temperature effect when the InSb thin film is used as magnetic sensor.

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Compensation Method of Position Signal Error with Misaligned Hall-Effect Sensors of BLDC Motor

  • Park, Joon Sung;Choi, Jun-Hyuk;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • v.11 no.4
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    • pp.889-897
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    • 2016
  • This paper presents an improved approach for compensating rotor position signal displacement in brushless DC (BLDC) motors with misaligned hall-effect sensors. Typically, the hall-effect sensors in BLDC motors are located in each phase and positioned exactly 120 electrical degrees apart. However, limitations in mechanical tolerances make it difficult to place hall-effect sensors at the correct location. In this paper, a position error compensator to counteract the hall-effect sensor positioning error is proposed. The proposed position error compensator uses least squares error analysis to adjust the relative position error and back-EMF information to reduce the absolute offset error. The effectiveness of the proposed approach is verified through several experiments.

A Simple Fault Correction Method for Rotor Position Detection of Brushless DC Motor using a Latch Type Hall Effect Sensor

  • Baik In-Cheol;Joo Hyeong-Gil
    • Journal of Power Electronics
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    • v.5 no.1
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    • pp.62-66
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    • 2005
  • A simple fault correction method for rotor position detection of a brushless DC(BLDC) motor with trapezoidal back EMF(electromotive force) using a Hall effect latch unit is presented. The reason why the Hall effect latch unit does not operate properly during the startup of a BLDC motor is thoroughly explained. To solve this problem, a simple code change method and its hardware implementation issues are proposed and discussed.

ON RIVLIN-ERICKSON ELASTICO-VISCOUS FLUID HEATED AND SOLUTED FROM BELOW IN THE PRESENCE OF COMPRESSIBILITY, ROTATION AND HALL CURRENTS

  • Gupta, Urvashi;Sharma, Gaurav
    • Journal of applied mathematics & informatics
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    • v.25 no.1_2
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    • pp.51-66
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    • 2007
  • A layer of compressible, rotating, elastica-viscous fluid heated & soluted from below is considered in the presence of vertical magnetic field to include the effect of Hall currents. Dispersion relation governing the effect of viscoelasticity, salinity gradient, rotation, magnetic field and Hall currents is derived. For the case of stationary convection, the Rivlin-Erickson fluid behaves like an ordinary Newtonian fluid. The compressibility, stable solute gradient, rotation and magnetic field postpone the onset of thermosolutal instability whereas Hall currents are found to hasten the onset of thermosolutal instability in the absence of rotation. In the presence of rotation, Hall currents postpone/hasten the onset of instability depending upon the value of wavenumbers. Again, the dispersion relation is analyzed numerically & the results depicted graphically. The stable solute gradient and magnetic field (and corresponding Hall currents) introduce oscillatory modes in the system which were non-existent in their absence. The case of overstability is discussed & sufficient conditions for non-existence of overstability are derived.

Hall Effect Characteristics of InSb Thin Film (InSb 박막의 홀효과 특성)

  • Lee, Woo-Sun;Cho, Jun-Ho;Choi, Kun-Woo;Jeong, Yong-Ho;Kim, Sang-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.6-9
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    • 2000
  • InSb hall effect of multilayerd structures were investigated. According to variation of magnetic field measured hall coefficient, Hall mobility, carrier density and hall voltage. For the measurement of electrical properties of hall device, evaperated InSb thin film fabricated with series and parallel multilayers. We found that the XRD analysis of InSb thin film showed good properties at $200^{\circ}C$, 60 minutes. Resistance of ohmic contact increased linearly due to increasing current. Some of device fabrication technique and analysis of Hall effect were discussed.

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Temperature Dependent Mdbility Characteristics of InSb Thin Film (홀센서 InSb 박막 이동도의 온도의존성)

  • 이우선;조준호;최권우;김남오;김형곤;김상용;서용진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.582-585
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    • 2001
  • InSb temperature dependent hall effect of multilayerd structures were investigated. According to variation of magnetic field measured hall coefficient, Hall mobility, carrier density and hall voltage. For the measurement of electrical properties of hall device, evaperated InSb thin film fabricated with series and parallel multilayers. We found that the XRD analysis of InSb thin film showed good properties at 200$^{\circ}C$, 60 minutes. Resistance of ohmic contact increased linearly due to increasing current. Some of device fabrication technique and analysis of Hall effect were discussed.

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Temperature Dependent Hall Effect Characteristics of InSb Thin Film (InSb 박막 홀효과의 온도의존성)

  • 이우선;조준호;최권우;김남오;김상용
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.21-24
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    • 2000
  • lnSb temperature dependent hall effect of multilayerd structures were investigated. According to variation of magnetic field measured hall coefficient, Hall mobility, carrier density and hall voltage. For the measurement of electrical properties of hall device, evaperated InSb thin film fabricated with series and parallel multilayers. We found that the XRD analysis of InSb thin film showed good properties at 20$0^{\circ}C$, 60 minutes. Resistance of ohmic contact increased linearly due to increasing current. Some of device fabrication technique and analysis of Hall effect were discussed.

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Quantum Hall Effect of CVD Graphene

  • Kim, Young-Soo;Park, Su-Beom;Bae, Su-Kang;Choi, Kyoung-Jun;Park, Myung-Jin;Son, Su-Yeon;Lee, Bo-Ra;Kim, Dong-Sung;Hong, Byung-Hee
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.454-454
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    • 2011
  • Graphene shows unusual electronic properties, such as carrier mobility as high as 10,000 $cm^2$/Vs at room temperature and quantum electronic transport, due to its electronic structure. Carrier mobility of graphene is ten times higher than that of Silicon device. On the one hand, quantum mechanical studies have continued on graphene. One of them is quantum Hall effect which is observed in graphene when high magnetic field is applied under low temperature. This is why two dimension electron gases can be formed on Graphene surface. Moreover, quantum Hall effect can be observed in room temperature under high magnetic field and shows fractional quantization values. Quantum Hall effect is important because quantized Hall resistances always have fundamental value of h/$e^2$ ~ 25,812 Ohm and it can confirm the quantum mechanical behaviors. The value of the quantized Hall resistance is extremely stable and reproducible. Therefore, it can be used for SI unit. We study to measure quantum Hall effect in CVD graphene. Graphene devices are made by using conventional E-beam lithography and RIE. We measure quantum Hall effect under high magnetic field at low temperature by using He4 gas closed loop cryostat.

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Effects of Grain Size Distribution on the Mechanical Properties of Polycrystalline Graphene

  • Park, Youngho;Hyun, Sangil
    • Journal of the Korean Ceramic Society
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    • v.54 no.6
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    • pp.506-510
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    • 2017
  • One of the characteristics of polycrystalline graphene that determines its material properties is grain size. Mechanical properties such as Young's modulus, yield strain and tensile strength depend on the grain size and show a reverse Hall-Petch effect at small grain size limit for some properties under certain conditions. While there is agreement on the grain size effect for Young's modulus and yield strain, certain MD simulations have led to disagreement for tensile strength. Song et al. showed a decreasing behavior for tensile strength, that is, a pseudo Hall-Petch effect for the small grain size domain up to 5 nm. On the other hand, Sha et al. showed an increasing behavior, a reverse Hall-Petch effect, for grain size domain up to 10 nm. Mortazavi et al. also showed results similar to those of Sha et al. We suspect that the main difference of these two inconsistent results is due to the different modeling. The modeling of polycrystalline graphene with regular size and (hexagonal) shape shows the pseudo Hall-Petch effect, while the modeling with random size and shape shows the reverse Hall-Petch effect. Therefore, this study is conducted to confirm that different modeling is the main reason for the different behavior of tensile strength of the polycrystalline structures. We conducted MD simulations with models derived from the Voronoi tessellation for two types of grain size distributions. One type is grains of relatively similar sizes; the other is grains of random sizes. We found that the pseudo Hall-Petch effect and the reverse Hall-Petch effect of tensile strength were consistently shown for the two different models. We suspect that this result comes from the different crack paths, which are related to the grain patterns in the models.

A Study on the Antiferromagnetism and Exchange Anisotropy for Co/Pd Multilayered Thin Films by the Analysis of the Hall Effect (Hall 이력곡선 분해에 의한 Co/Pd 다층박막에서의 Antiferromagnetism 및 Exchange Anisotropy 분석)

  • 정진덕;이행기;김상록;이성래
    • Journal of the Korean Magnetics Society
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    • v.3 no.4
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    • pp.269-276
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    • 1993
  • Co/Pd multilayered thin films with various ratios of Co sublayers to Pd sublayers(nCo/nPd = 1/4, 2/4, 3/4, 5/4) were fabricated at different substrate temperatures($R.\;T.,\;100,\;150,\;200\;^{\circ}C$) with the conventional vacuum evaporation method, and their Hall voltage hysteresis curves were measured. These Hall curves were decomposed on the basis of the superpose of the transverse Hall effect term from the magnetizations of Co and Pd sublayers and the magnetoresistivity term, by the optimal fitting method. In the results, both of the ferromagnetic and anti ferromagnetic states coexisted through whole samples, and the uniaxial or unidirectional easy axis type Hall hysteresis curves occured were dependent upon the effects of the exchange anisotropy between both magnetic states and the domain wall pinning by the antiferromagnet inclusions.

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