• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.99-106
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• 2005

In this study, the electromagnetic characteristics of a flat-type two-dimensional proportional solenoid were analyzed by the magnetic reluctance method. The equivalent magnetic circuit equation for the solenoid was derived by modeling the reluctance of air gaps and magnetic structural components such as pole core, armature and yoke. It was solved iteratively because of the nonlinear magnetization properties of the iron parts. The solutions showed good agreement with experimental data. Based on the equivalent magnetic circuit equation, the influence of design parameters on the force-to-armature displacement curves was mathematically derived and experimentally verified. In this way, dominant design parameters could be analytically determined.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.125-132
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• 1993

On this study, magnetic force versus input currents is analyzed by modeling taper plunger type proportional electromagnet of ISC valve using the permernce method. And, the reliabiliy of simulation is verified by comparing the experimental values with the calaulate magnetic force. From the result of this study, it is found that the taper angles at plunger and core, the length of air gap between plunger and yoke are the prumary factors in designing taper plunget type proportional electromagnet. Magnetic force is decreased as a whole according to increasing the air gap between pluger and yoke, and vise versa. But, the magnetic force is not proportional to current, when the air gap is very small. In case of decreasing the taper angle of pluger, the stroke range of plunger where magnetic force is proportional to current becomes farther from core.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1201-1203
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• 2011

이 논문은 가속기에 사용되는 전자석용 전원장치 개발에 대해서 기술하였다. 이 전원장치는 DSP TMS320F2808과 ADCs, FPGA를 이용한 디지털 신호처리 기술을 적용하여 5ppm 이하의 출력 전류 안정도를 가진다. 여기서는 전원장치의 입력 및 출력 필터, 비례적분 보상기 등에 대한 설계, 전원장치 모의실험 결과 및 제작 후 출력 전류의 안정도, 시스템의 주파수 특성 등 여러 성능의 측정 결과에 대하여 기술하였다.

• Nuclear Engineering and Technology
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• v.23 no.4
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• pp.438-443
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• 1991

The operational characteristics of the duoplasmatron ion source are investigated in order to obtain the maximum achievable extraction current of the $He^+$ ion beam with the small divergence. Under the variations of the gas pressure, the arc current, the magnet current and the extraction voltage of the ion source, the change of the extracted $He^+$ ion beam current is observed. An oxide filament, the mixture of BaO and SrO coated on Ni meshes, is used as the hot cathode, and its average lifetime is about 100 hours. The extraction current is linearly proportional to the arc current. As the magnet current of the ion source is increased, the extraction current increases, but the beam divergence becomes larger. The maximum extraction current is obtained at the source pressure of 0.084 Torr. The extraction current is proportional to the extraction voltage raised to the power of 3/2 as estimated from theory. At the extraction voltage of 5.72 kV, the maximum extraction current of 50 $\mu$A is obtained under the optimized extraction condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.87-96
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• 1996

The proportional pressure control valve(PCV) is an essential component in the open loop controlled rear wheel steering gear of the four wheel steering(4WS) system on the passenger car. The valve should have versatile functions and higher performance. But, it is hard to find the proportional pressure control valve suitable for the 4WS system. In this paper, the determination of the valve parameters was studied by the stability discrimination and the characteristic analysis for the purpose of the development of a new PCV for the 4WS. The mathematical model of the valve was derived from the valve-cylinder system and the programme for numerical computation was developed. The transfer function of the system was obtained from the mathematical model. The characteristics of the valve were inspected through the experiment and compared to those obtained by numerical method. And then the stability discrimination of the system was done by root locus and the analysis of characteristics was done by the developed programme. From the experiment and the analysis of characteristics was done by the developed programme. From the experiment and the inspection, the appropriation of mathematical model and the usefulness of the programme were confirmed. And the parameters which might affect the performance of the valve can be determined by considering the stability discrimination, the characteristics analysis and required functions.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.56.1-56.1
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• 2011

본 연구에서는 90% 이상의 스퍼터링 전극 사용이 가능한 새로운 방식의 스퍼터링 증착 기술을 개발하였다. 본 장치는 기존의 마그네트론 스퍼터링법과 달리 플라즈마 발생부와 스퍼터링 전극이 따로 존재하며, 플라즈마 발생부에서 생성된 이온을 통해 전극 스퍼터링을 일으킨다. 플라즈마 발생부에서 생성된 $10^{13}cm^{-3}$ 이상의 고밀도 Ar 플라즈마는 전자석 코일을 통해 형성된 자기장을 따라 스퍼터링 전극으로 균일하게 수송되며, 스퍼터링 전극 전압에 의해 가속된 이온은 전극 대부분 영역에서 스퍼터링을 발생시킨다. 스퍼터링 전류는 플라즈마 발생부의 전력에만 비례하며 직경 100 mm 스퍼터링 전극 사용시 최대 3.8 A의 이온 전류 값을 나타냈다. 따라서 스퍼터링 전압과 전류의 독립적인 제어가 가능하며 일정한 스퍼터링 전류 조건에서 300 V 이하의 저전압 스퍼터링 공정 및 1 kV 이상의 고전압 스퍼터링 공정이 가능하였다. 이를 통해 스퍼터링된 이온 및 중성입자의 에너지 조절이 가능하며, 다양한 증착공정 분야에 응용 가능하다.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.100-107
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• 1993

In this study, it is analyzed that an electromagnet whose generating force is proportional to constant current through coil in its coperating range. To find arelation between magnetic force and the structure in electromagnet, computer simulation method is used by permeance modeling method. When the electromagnet is applied to flow control valve, the relation between input current and flow is found. In order to get a reliability of computer simluation, the simulation results are compared to the experimental result. As the simulation is processed repeatedlyl. it is found that the gap size between plunger and guide steel and the length of tapered brass ring are important factors in electromaget.