• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.325-332
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• 2017

The engine cooling system is a device that maintains the temperature in the engine room at an appropriate level by driving a cooling fan when the temperature in the engine room generated during the vehicle operation occurs over a certain temperature. In recent years, the vehicle cooling system has changed to an electronic system. Therefore, in this paper, we design and develop a hall sensor based electronic engine cooling system. In this paper, a hall sensor module and an actuator module for engine cooling control system are designed. In order to verify the performance of the designed module, the magnetic field control was verified through the simulation of the diameter and the head of the coil.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.217-219
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• 2009

A GMI magnetic field sensor working based on time-coded principle has been investigated and designed. The laboratory model has been constructed and tested carefully, demonstrating the sensitivity of $3\;{\mu}s/{\mu}T$ in the field range of ${\pm}100\;{\mu}T$. An amorphous thin wire, $100\;{\mu}m$ in diameter ${\times}50\;mm$ in length, was chosen to be sensing element which was fit into a small field modulation coil of 60 mm in length. The sensor is working based on a time-coded principle that, with the magnetic field modulation was chosen in range of hundreds of Hz, the change in time interval of two adjacent GMI peaks relating to external DC magnetic field is proportional to the intensity of the external field to be measured. This mechanism has made a great improvement to the linearity of the sensor.

• Journal of Sensor Science and Technology
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• v.6 no.2
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• pp.87-94
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• 1997

Impedance analysis of a Solenoid sensor to detect the cross-sectional area of non-ferromagnetic stranded conductors is described in this paper. To inspect electromagnetic characteristics of conductive materials, a nondestructive test eddy current sensor with an encircling coil is chosen. As solving Maxwell equation, normalized impedance response of the sensor within a conducting rod is modeled and the results are expanded to the stranded wires. Geometrical property affecting on stranded structure is considered and a numerical and experimental study is also presented.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2254-2256
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• 2000

This paper presents an implantable telemetry LC resonance-type pressure sensor for the measurement of the ventricle pressure. This sensor consists of a capacitor and an inductor. This resonant circuit is magnetically coupled with an external antenna coil. The resonance frequency of the circuit decreases as the sensor capacitance is increased by the applied pressure. The inductance and the capacitance are 428nH and 0.98${\mu}F$, respectively. The resonance frequency is 245.7MHz when the differential pressure is zero. The sensitivity of the sensor is 9.477kHz/Pa.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.283-292
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• 2020

Current sensors that use a Hall element and Hall IC to measure the magnetic fields generated in steel silicon core gaps do not distinguish between direct and alternating currents. Thus, they are primarily used to measure direct current (DC) in industrial equipment. Although such sensors can measure the DC when installed in expensive equipment, ascertaining problems becomes difficult if the equipment is set up in an unexposed space. The control box is only opened during scheduled maintenance or when anomalies occur. Therefore, in this paper, a method is proposed for facilitating the safety management and maintenance of equipment when necessary, instead of waiting for anomalies or scheduled maintenance. A Bluetooth 4.0 low-energy current-sensor system based on near-field communication is used, which compensates for the nonlinearity of the current-sensor output signal using a piecewise linear model. The sensor is controlled using its generic attribute profile. Sensor nodes and cell phones used to check the signals obtained from the sensor at 50-A input currents showed an accuracy of ±1%, exhibiting linearity in all communications within the range of 0 to 50 A, with a stable output voltage for each communication segment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.171-176
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• 2013

In this paper, we present a MEMS (micro-electro-mechanical system) implantable blood pressure sensor which has designed and fabricated with consideration of size, design flexibility, and wireless detection. Mechanical and electrical characterizations of the sensor were obtained by mathematical analysis and computer aided simulation. The sensor is composed of two coils and a air gap capacitor formed by separation of the coils. Therefore, the sensor produces its resonant frequency which is changed by external pressure variation. This frequency movement is detected by inductive coupling between the sensor and an external antenna coil. Theoretically analyzed resonant frequency of the sensor under 760 mmHg was calculated to 269.556 MHz. Fused silica was selected as sensor material with consideration of chemical and electrical reaction of human body to the material. $2mm{\times}5mm{\times}0.5mm$ pressure sensors fitted to radial artery were fabricated on the substrates by consecutive microfabrication processes: sputtering, etching, photolithography, direct bonding and laser welding. Resonant frequencies of the fabricated sensors were in the range of 269~284 MHz under 760 mmHg pressure.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.311-311
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• 2003

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.72-76
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• 2003

We developed a polarimetric fiber-optic current sensor using a length of twisted fiber and a Faraday rotator mirror which was used to suppress the linear birefringence effect. A gold coated mirror was also used as the sensor coil reflector, and the results were compared with the case of FRM. From the experimental results, it is clear that the FRM greatly enhances the stability of the fiber optic current sensor output..

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1884-1886
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• 2002

At present, the variable sensors are applied to detect PD pulse signals, UHF sensor, AE sensor and etc. In this paper we used the Rogowski sensor to detect PD pulse signals in air. We did performed test simulation and niddle to plane electrode structure for PD source. We compared Rogowski sensor with conventional type PD detector to detect discharge signals in air.

• Journal of Magnetics
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• v.14 no.3
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• pp.129-131
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• 2009

A time-coded giant magnetoimpedance (GMI) magnetic field sensor was investigated and designed. The successfully constructed and tested laboratory model demonstrated a sensitivity of 5 ${\mu}s/{\mu}T$ in the field range of $\pm200{\mu}T$. The sensing element in the form of an amorphous thin wire, 100 mm in diameter $\times50$ mm long, was fit into a small field modulation coil of 60 mm length. At a magnetic field modulation in the range of hundreds of Hz, the change in time interval of two adjacent GMI voltage peaks was linearly related to the external magnetic field to be measured. This mechanism improved the sensor linearity to better than 0.3% in the measuring range of $\pm200{\mu}T$.