• Journal of the Korean Magnetics Society
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• v.20 no.5
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• pp.178-181
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• 2010

Search coil magnetometer has been used for detection of ac magnetic field with high sensitivity. To reduce demagnetizing factor of core and increase S/N ratio of search coil magnetometer, the core was divided by two parts and coil was wound on each cores. Two coils were connected serially and put into amplifier as differential mode. Constructed 120 mm length search coil magnetometer shows linearity of 0.03%, sensitivity of 9.3 mV/nT, and resolution of 20 pT at 1 Hz.

• Journal of the Korean Magnetics Society
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• v.26 no.2
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• pp.62-66
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• 2016

We designed a model composed a ring type magnet, a yoke, and a sensing coil buried in a projectile for calculating the muzzle velocity based on the voltage induced from sensing coil by simulation. The muzzle velocity was calculated from the master curve obtained through the voltage induced from sensing coil by simulation. The induced voltage increased with increasing the diameter of sensing coil. The projectile's velocity was proportional to the induced voltage when the sensing coil was buried in projectile. The projectile will be surely exploded at the target region by inputting the information of muzzle velocity variation corrected the diameter effect of induced voltage of sensing coil.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.4
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• pp.389-396
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• 2015

A coil design of pulse induction metal detectors has been described. The search coil was demonstrated by using the wire with the diameter of 0.3 mm, 0.5 mm and 1.0 mm and the dielectric plate with the $30cm{\times}30cm$ and $35cm{\times}35cm$, the time constant and the currents of the coil as the variation of the coil size and the number of coil turns was characterized. The coil parameters like the resistance, the inductance and the time constants as the variation of the diameter of the wire, the coil size and the number of coil turns were compared and analysed through the calculation and the measurement. In addition, investigating the coil currents as the variation of the input pulse width, the coil design of pulse induction metal detectors has been discussed.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.132-133
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• 2002

자속밀도를 측정하기 위한 방법으로 Hall 효과; NMR, Fluxgate 등의 다양한 방법등을 사용하고 있다. 그러나 가장 많이 사용되는 방법이 Faraday 전자기 유도 법칙을 이용하여 자속밀도를 측정하는 방법이다. 이 경우 탐지코일에 유도되는 기전력이 자속의 시간 변화율에 비례하기 때문에 자속을 측정하기 위해서는 탐지코일에 유도되는 기전력을 적분을 하여야 한다. (중략)

• Proceedings of the Korean Magnestics Society Conference
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• 2014.11a
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• pp.163-164
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• 2014

• Proceedings of the Korean Magnestics Society Conference
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• 2013.12a
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• pp.23-24
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• 2013

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.4
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• pp.285-289
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• 2000

This study suggests a rebar detection technique for simultaneous detection of size and cover of embedded reinforcement in concrete. The structure of the probe made in this study is somewhat different from commercial ones. This probe has three sensing coils. Rebar size and cover depth can be evaluated by detecting and analyzing the signal from them. Amplitude and phase variation of each coil in the probe was investigated using an impedance analyzer and the loci of transfer functions of the coils were analyzed. The locus of transfer function from the sensing coil positioned inside excitation coil was simple as well known, but the others from the coils outside excitation coil were not so. Actual experiment on rebar detection was performed with our probe and an eddy current test system for various rebar sizes and depths. The signal shape according to variation of cover depths showed the same tendency with the transfer function loci acquired by impedance analyzer. The different variation pattern of signal enabled to evaluate rebar size and cover depth simultaneously.

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.206-211
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• 2002

We have constructed a new kind of magnetic motion capture sensor based on the pulse magnetic field method. 3-orthogonal magnetic pulse fields were generated in turns only one period of sinusoidal waveform using 3-orthogonal magnetic dipole coils, ring counter and analog multiplier. These pulse magnetic fields were measured with 3-orthogonal search coils, of which induced voltages by the x-, y-, and l-dipole sources using S/H amplifier at the time position of maximum induced voltage. Using the developed motion capture sensor, we can measure position of sensor with uncertainty of ${\pm}$0.5％ in the measuring range from ${\pm}$0.5 m to ${\pm}$1.5 m.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.652-657
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• 1986

본 연구는 시야나 머리운동을 구속하지 않고 수평 및 수직 머리운동을 측정하여 처리하는 방법에 관한 것이다. 이를 위해 Helmholtz 코일을 적절히 구성하여 균일 자계를 발생시키고 탐지 코일을 이용하여 머리운동의 동적 특성을 검출하고, 검출된 신호는 신호처리 장치를 구성하여 처리하는 방법을 개발하고 다른 연구결과와 비료 고찰하였다.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.115-117
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• 1992

고주파 자장 유도를 사용하는 공막 탐지 코일(scleral search coil) 법에 의한 안구 운동의 측정은 분해능, DC 안정성의 장점때문에 정밀 측정의 대표적인 기법으로 정착되었다. 본 연구에서는 공막 탐지 코일법의 한 변형으로서 비교적 간단한 자장 구동 및 탐지회로를 채택하였고 보다 논은 착용감을 주도록 고안된 금박 공막테를 사용하여 안구 운동을 측정한 결과에 관한 것이다.