• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.68-71
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• 2000

In this study, A set-up for measuring a initial permeability of soft-ferrite powder was developed with a differential transformer coil. To measure a initial permeability of magnetic powder is cumbersome since there are not any measuring equipment and method. A magnetic powder is currently used for a magnetic fluid and microwave absorber materials, and the initial permeability of the magnetic powders is very important to be evaluated a powder for some applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.86-90
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• 2000

In this study, A equipment for measuring the initial permeability of soft-ferrite powder was developed by using a differential transformer coil, and was investigated demagnetizing factors. To measure the initial permeability of magnetic ceramic powder is cumbersome since there are not any measuring equipment and method. Magnetic powder is currently used for a magnetic fluid and microwave absorber materials, and the initial permeability of the magnetic powder is very important to be evaluated a powder for some applications.

• 대한전자공학회논문지SD
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• 제48권12호
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• pp.97-102
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• 2011

본 논문에서는 LVDT 구조를 이용한 신호 매핑 기반의 새로운 변위측정 알고리즘을 제안한다. 제안하는 방식은 상대 값을 이용한 신호 매핑방식을 사용하기 때문에 PCB상에 구현되는 코일 패턴이나, 트랜스 소자의 변수들에 독립적으로 동작할 수 있다. 이는 절대 값을 사용하면서 발생하는 다수의 튜닝작업이 필요 없고 단지 상대 값을 추출하기 위해 최종단계에서의 범위를 측정하는 캘리브레이션 공정만 필요하다. TI DSP 칩셋인 TMS320F2812에 코일 패턴이 다른 다수의 보드를 통하여 본 논문에서 제안하는 기법을 구현해 본 결과, PCB 코일 패턴이 조악하더라도 높은 정밀도와 신뢰성을 갖는 출력 신호를 얻음으로써 제안하는 기법의 우수성을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.60-62
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• 1994

In this paper, the LVDT with compensating secondary coil and secondary current boost circuit is proposed. The LVDT was experiment with a test device, and analyzed with numerical method (FEM), It is shown that the LVDT has a good linearities for the measurement of the displacement and position, etc..

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1687-1689
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• 2000

In this study, a measuring system of the initial permeability of soft-ferrite powder was developed by using a differential transformer coil. and was investigated demagnetizing factors. Magnetic powder is extensively used for a magnetic fluid and microwave absorber materials etc. In these applications, it is very important for us to measure the initial permeability of magnetic ceramic powder. Unfortunately there are not any measuring equipment and method directly up to the present.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.310-315
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• 2007

The axial-flow type blood pump(XVAD) which has been developed in our group consists of mechanical parts (an impeller, a diffuser and a flow straightener) and electrical parts (a motor and a magnetic bearing). The magnetic bearing system fully levitates the impeller to remove mechanical coupling with other parts of the pump with constant gap, which needs non-contact type gap sensing. Conventional gap sensors are too large to be adopted to the implantable axial -flow type blood pump. Thus, in this paper, the compact eddy current type gap sensor system proper for the implantable axial-flow type blood pump was developed and its performance was evaluated in vitro. The developed eddy current type gap sensor system is a transformer type and has a differential probe. Sensor coil(probe) has small dimensions(6 mm diameter, 2 mm thickness) and its optimal inductance was determined as 0.068 mH for the measurement range of $0\sim3mm$. It could be manufactured with 130 turns of the 0.04 mm diameter copper coil. The characteristics of the developed eddy current type gap sensor system was evaluated by in vitro experiment. At experiment, it showed satis(actory performance to apply to the magnetic bearing system of the XVAD. It could measure the gap up to 3mm, but the linearity was decreased at the range of $1.8\sim3.0mm$. Moreover, it showed no difference in different media such as the water and the blood at the temperature range of $35\sim40^{\circ}C$.