• Journal of Magnetics
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• v.12 no.1
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• pp.40-44
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• 2007

The Planar Hall effect in a spin valve structure has been applied as a biosensor being capable of detecting $Dynabeads^{(R)}$ M-280. The sensor performance was tested under the application of a DC magnetic field where the output signals were obtained from a nanovoltmeter. The sensor with the pattern size of $50{\times}100{\mu}m^2$ has produced high sensitivity; especially, the real-time profiles by using that sensor revealed significant performance at external applied magnetic field of around 7.0 Oe with the resolution of 0.04 beads per $\mu m^2$. Finally, a successful array including 24 patterns with the single sensor size of $3{\times}3{\mu}m^2$ has shown the uniform and stable signals for single magnetic bead detection. The comparison of this sensor signal with the others has proved feasibility for biosensor application. This, connecting with the advantages of more stable and high signal to noise of PHR sensor's behaviors, can be used to detect the biomolecules and provide a vehicle for detection and study of other molecular interaction.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.3
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• pp.266-272
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• 2014

This study proposes a closed-loop shaping control method with $H_{\infty}$ optimization for optical image stabilization (OIS) in mobile phone cameras. The image stabilizer is composed of a horizontal stage constrained by ball bearings and actuated by the magnetic force from voice coil motors. The displacement of the stage is measured by Hall effect sensors. From the OIS frequency response experiment, the transfer function models of the stage and Hall effect sensor were identified. The weight functions were determined considering the tracking performance, noise attenuation, and stability with considerable margins. The $H_{\infty}$ optimal controller was executed using closed-loop shaping and limiting the controller order, which should be less than 6 for real-time implementation. The control algorithm was verified experimentally and proved to operate as designed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.86.3-86
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• 2001

Hall effect sensor using 7um, 1.7 ohm-cm or 10um, 3.5 ohm-cm Bipolar process was successfully developed. The Hall sensor consists of various patterns, such as regular shapes, rectangles, diamond, hexagon and cross shapes to optimize offset voltage and sensitivity for proper applications. In order to measure offset voltage in chip scale the Agilent company´s 4156C and Nano-Voltage Meter were used and the best structure in offset voltage was finally selected by using ceramic package. The patterns appear to be the quadri-rectangular patterns entirely and three-parallelogram patterns. The measured offset voltages were found to be about 173-365uV. Meanwhile, in ...

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.187-190
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• 1991

The analytical model to investigate the effects of the drift and diffusion carrier transport upon the Hall effect is presented and applied to the general PN junction structure. The diffusion current effect on the Hall coefficient can not be considered in the conventional model, which produces the conversion of the direction of the induced Hall field between measured and calculated values. The proposed analytical model which considers the diffusion current effect provides the coincident results with the previous experimental results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.49-52
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• 2000

In the current development of magnetic sensors based on the Hall effect, the following two approaches can be distinguished. The first, one tries to build better sensor based on conventional Hall devices. The innovations come through a better understand of the details If the operating principle and secondary effects, and through the application If ever-improving microelectronics technology. In the second approach, one hopes to build better sensors by making use of the Hall effect in active devices, such as magneto-transistors and MAGFET. In this paper, we study magnetic properties of Hall device fabricated with series and parallel multilayers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.49-52
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• 2000

In the current development of magnetic sensors based on the Hall effect, the following two approaches can be distinguished. The first, one tries to build better sensor based on conventional Hall devices. The innovations come through a better understand of the details if the operating principle and secondary effects, and through the application if ever-improving microelectronics technology. In the second approach, one hopes to build better sensors by making use of the Hall effect in active devices, such as magneto-transistors and MAGFET. In this paper, we study magnetic properties of Hall device fabricated with series and parallel multilayers.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.251-253
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• 2002

We have fabricated a novel Vertical Trench Hall-Effect Device sensitive to the magnetic field parallel to the sensor chip surface for non-contact angular position sensing applications. The Vertical Trench Hall-Effect Device is built on SOI wafer which is produced by silicon direct bonding technology using bulk micromachining, where buried $SiO_2$ layer and surround trench define active device volume. Sensitivity up to 150 V/AT is measured.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.33-41
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• 2001

Wire ropes have been widely used in industrial applications, wherever heavy weight should be carried safely or mechanical energy should be transmitted fast. Especially, wire rope failures in operating elevator may lead to extensive property damage and serious injury to nearby personnel. Hence, it is very important to inspect wire rope periodically. Failure defection of wire rope requires fundamental knowledge of wire rope construction, rope behavior, properties of fault, sensing and signal processing method. In this research, the development of a new fault detecting system incorporating Hall-effect sensors to detect flaws such as abrasion, broken wire, corrosion and deformation for aged wire ropes in elevator, is described. For using a detector as a portable instrument, several performances for implementing sensing part with Hall-effect sensor, analog signal processing unit and programs are described. Experiments and field testing results for the implemented detecting system are also given. As a result, it is verified that the detecting system has good efficiency for inspecting faults of aged wire ropes in service.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.257-258
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• 2008

Hall-type current sensors have been widely used in many fields such as elevator and train system. To estimate lifetime of hall-type current sensors, an accelerated life test with real-time monitoring system simultaneously was designed and performed in high temperature environment with three different temperatures. From the experimental results, activation energy was about 0.9 eV, and acceleration factor was about 450 based on Arrhenius model. As a results, $B_{10}$ lifetime of hall-type current sensor is estimated to be 65,460 hours.

• Journal of the Korean Magnetics Society
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• v.23 no.3
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• pp.89-93
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• 2013

In this study, magnetic concentrators which could be used to enhance sensitivity of Hall effect sensor were analyzed by using FEM. The parameters for FEM analysis were the thickness and edge shape of magnetic concentrator and relative position of magnetic concentrator against Hall element. Magnetic field in z direction decreased with increasing of the thickness of magnetic concentrator, of which tendency was similar to apparent relative permeability calculated with demagnetizing factor of magnetic concentrator. There were optimal thickness and edge shape of magnetic concentrator according to the relative position of magnetic concentrator against Hall element.