• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.59-61
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• 2006

The single phase switched reluctance motor(SRM) is simpler in control circuit because the number of switching devices is fewer than the poly phase SRM. The energy density per unit volume is very big because all stator poles are excited simultaneously by a single switching power source. But it must be provided a starting device on account of not being generated the starting torque at specific rotor positions. And also it has some demerits that have a torque ripple, noise and vibration because of being excited by switching pulse power source. Therefore, to make up for these demerits, it is realized many studies for the structure design used by computer and the operating methods by power electronics technique. In this paper, we'll present the comparison of the single phase SRM with the various rotor pole face types, as like stepped rotor pole face type and general rotor pole face type. For the torque characteristics analysis.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.47-49
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• 2003

수직 기록 방식은 그 기록 방식의 차이로 인하여 수평 기록 방식에서 쓰여 오던 Write Head의 Design을 적용하였을 경우 기록 밀도를 높이는데 많은 문제점과 낮은 기록 밀도 상승률을 동반하게 된다. 따라서 수직 기록 방식의 자기 기록에서는 수직 기록 방식에 적합한 Write Head의 Design을 적용하여야만 한다. 본 논문에서는 3차원 유한요소법을 이용하여 수직 기록용 Write Head의 한 종류인 SPT Head(Single Pole Tip Head)를 최적 설계하여 그 Write Field의 특성을 분석 제시하였다. 또한 기록 Media의 차이에 따른 기록 특성을 분석하기 위하여 기존 Single Layer 방식과 SUL (Soft Magnetic Under layer)를 사용한 Double Layer 방식을 이용하였을 경우 SUL이 자기 기록에 미치는 영향에 대한 내용을 연구 분석하여 제시하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.6
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• pp.510-516
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• 2017

This paper proposes a single-stage interleaved totem-pole on-board battery charger with a simple structure and a reduced component count. Apart from achieving ZVS turn-on of all switches and ZCS turn-off of all diodes, this charger does not require an input filter due to its CCM operation and bulky electrolytic capacitors, which in turn result in a high power density. A single-stage power conversion technique is applied to the interleaved structure in order to achieve a high power density and high efficiency. A 2.5 kW prototype of the proposed charger is also built and tested to validate the proposed operation.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1106-1116
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• 2008

Single-pole transmission structures which are supported by drilled shaft foundations are usually subjected to large overturning moments with modest vertical and lateral loads. To analyze the behavior of the drilled shaft under such loading conditions, an analytical model was developed based on beam-column and subgrade reaction methods. Field model tests were performed to calibrate the developed analytical model in which additional subgrade spring models were adopted. The field test results estimated from the calibrated analytical model were compared with those calculated by one spring model and other commercial program. According to the comparison study, the developed analytical model was proven to be a useful tool to analyze the laterally loaded behavior of foundations for single-pole structures.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.805-806
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• 2006

Single phase switched reluctance motor has a merit in practical use because it has simple operating drives and control systems, very high energy density per unit volume comparing with three phase SRM. But it must have a starting device. This paper presents a single phase SRM model with a stepped rotor pole, so as to reduce the torque ripple. Also it is simulated the designed prototype model by FEM for the prediction of characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.249-251
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• 2005

A method of double-pole construction is developing to strengthen the mechanical intensity of the electric poles. Therefore the mechanical properties of the double-pole were researched in this paper. First, considering field special quality electric poles were established. In the next tensile force was applied and stress distribution and fatigue load were examined. When a base of the pole is concrete, mechanical intensity of the double-pole increased about 1.7 times compared a single pole.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.868-870
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• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) can be use axial direction magnetic flux and radial direction magnetic flux at the same time. Then, it has higher energy density per unit volume and can be lessened the shaft length of motor or exciting magnetic force. Additionally, it's durability is good because it is simple structure and driving device. Prototype of Salient pole rotor type single phase SRM was fabricated by using parameters of three phase SRM and 3D FEM analysis. Also, driving device was fabricated for prototype. Speed and torque characteristic was confirmed through the experiments, and flux linkage, which is important parameter of SRM for generating torque, was measured. The induction emf was calculated by using ideal inductance graph and current graph. Calculated emf and measured emf was compared for confirming loss of prototype in this paper.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.887-888
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• 2006

Switched Reluctance Motor(SRM) is rotated by reluctance force generated between rotor pole and stator pole. So SRM must be switched by exciting current according to rotor position. but SRM takes the advantages of high speed driving and very simple structure. The single phase SRM can not be start by itself and torque ripple is generated more than multi-phase SRM. But mechanical structure and driver is simpler than multi-phase SRM. The single phase SRM driver is composed with the absolute encoder and DSP to control exciting section and current, and is supplied by constant voltage. So The paper is intend to measure the speed charactrer of double silent pole type SRM by using the unipolar driving curcuit.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.924-927
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• 2017

This paper presents a 6~18 GHz 8-bit true time delay (TTD) circuit. The unit delay circuit is based on m-derived filter with relatively constant group delay. The designed 8-bit TTD is implemented with two single-pole double-throw (SPDT) switches and seven double- pole double-throw (DPDT) switches. The reflection characteristics are improved by using inductors. The designed 8-bit TTD was fabricated using $0.18{\mu}m$ CMOS. The measured delay control range was 250 ps with 1 ps of delay resolution. The measured RMS group delay error was less than 11 ps at 6~18 GHz. The measured input/output return losses are better than 10 dB. The chip consumes zero power at 1.8 V supply. The chip size is $2.36{\times}1.04mm^2$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.183-188
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• 2004

A method of double-pole construction is developing to strengthen the mechanical intensity of the electric poles. Therefore the mechanical properties of the double-pole were researched in this paper. First, considering field special quality electric poles were established. In the next tensile force was applied and stress distribution and fatigue load were examined. When a base of the pole is concrete, mechanical intensity of the double-pole increased about 1.7 times compared a single pole. In the case of general soil base, the concrete base should be needed to expect the reinforcement effect of the double-pole.