• Applied Science and Convergence Technology
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• 제24권3호
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• pp.47-52
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• 2015

The correlation between admittance and dielectric spectroscopy of dielectric relaxation in lead scandium noibate, have been investigated. Lead scandium niobate, with composition $PbSc_{0.5}Nb_{0.5}O_3$, was prepared by conventional solid state synthesis. Conductance Y'(G), susceptance Y"(B) and capacitance C of lead scandium niobate as a function of frequency and temperature were measured. From the temperature-dependence of RLC circuit, insight into physical significance of the dielectric properties of lead scandium niobate is obtained. The relative strong frequency dependent of dielectric properties in lead scandium niobate is observed, and the phase transition occurred at a broad temperature region. Also, the value of critical exponent ${\gamma}$=1.6 showed on heating process. The long relaxation times part enlarged diffuse by conductivity effects with increasing temperature, and the ordering between $Sc^{3+}$ and $Nb^{5+}$ in PSN influences complex admittance and dielectric properties. Confirmed the typical characteristic of lead-type relaxor in the Raman spectra of lead scandium niobate and major ranges are between 400 and $900cm^{-1}$.

• 한국정밀공학회지
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• 제20권9호
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• pp.109-117
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• 2003

With development of high advanced technologies and skills, micro machining techniques also are being more functional and smaller. Some of the recently developed micro machining technologies are micro drilling, micro EDM, WEDG, LBM, micro milling, micro UVM etc. In these micro machining techniques, Micro -EDM is generally used for machining micro holes, pockets, and micro structures in difficult-cut-materials. For machining micro structures, first of all, tool electrode should be fabricated by WEDG process. In micro-EDM, parameters such as peak current, pulse width, duration time are very important to fabricate the tool electrode and micro structures. Developed experimental equipments are composed of RLC circuit with PWM. In this paper, using developed micro EDM machine, the characteristics of micro electro discharge machining are investigated at micro holes, slot, and pocket machining etc. Also the trends of tool wear are investigated in case of hole and slot machining.

• Journal of electromagnetic engineering and science
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• 제11권3호
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• pp.192-200
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• 2011

This paper proposes a new modeling method for estimating the impedance of an on-chip power/ground meshed plane. Frequency dependent R, L, and C parameters are extracted based on the proposed method so that the model can be applied from DC to high frequencies. The meshed plane model is composed of two parts: coplanar multi strip (CMS) and conductor-backed CMS. The conformal mapping technique and the scaled conductivity concept are used for accurate modeling of the CMS. The developed microstrip approach is applied to model the conductor-backed CMS. The proposed modeling method has been successfully verified by comparing the impedance of RLC circuit based on extracted parameters and the simulated impedance using a 3D-field solver.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.413-415
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• 1995

This paper presents a new approach in the design of multiple power output electronic ballasts for compact fluorescent lamps which power output range of 11W, 15W, 20W by using equivalent resistance and RLC equivalent circuit concept and frequency control. A multiple power output electronic ballast which adopts half-bridge inverter topology is set up to compare the results of PSpice simulation with experimental ones. Starting characteristics of lamp voltage, lamp current and light output are better than the existing electronic ballasts, and therefore is verified the validity of the proposed method.

• 한국철도학회논문집
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• 제7권1호
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• pp.65-69
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• 2004

In reference to this study, Part Ⅰ showed how the system respond to the harmonics originated from electric locomotives. That is, the system response to the harmonics was derived by computational algorithm with numerical formulas in theoretical aspects. However, Real catenary system has complex configuration of conductors and it is an important point that if we can consider the circuit element of catenary conductors as an uniformly distributed RLC element. Moreover, harmonic characteristics in electric locomotive depend on its operational modes. From these point of view, measurements of harmonics are performed for real railway power supply systems under the various operational modes, and spectrum and distortion analyses in measurement data are described.

• 한국표면공학회지
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• 제56권4호
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• pp.227-232
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• 2023

In this study, complex admittance as a function of temperature and frequency was measured to analyze the important relaxation properties of lead scandium niobate, which is physically important, although it is not an environmentally friendly electrical and electronic material, including lead. Lead scandium niobate was synthesized by heat treating the solid oxide, and the conductance, susceptance and capacitance were measured as a function of temperature and frequency from the temperature dependence of the RLC circuit. The relaxation characteristics of lead scandium niobate were found to be affected by contributions such as grain size, grain boundary characteristics, space charge, and dipole arrangement. As the temperature rises, the maximum admittance and susceptance increase in one direction, but the resonance frequency decreases below the transition temperature but increases after the phase transition.

• 전기전자학회논문지
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• 제18권4호
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• pp.552-558
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• 2014

본 논문에서는 원격 방사선 측정을 위한 ZigBee 원칩형 통신 모듈 설계방법을 제안한다. 제안된 ZigBee 원칩형 통신모듈 설계는 ZigBee 시스템 구성을 위해 일반적으로 사용되는 2개의 칩 제어 프로세서와 ZigBee RF 디바이스로 구성되는 방식을 한 개의 칩 모듈로 설계한다. 원격 방사선 측정을 위한 ZigBee 원칩형 통신 모듈은 무선통신 통합제어부, 센서 및 고전압 발생부, 충전 및 전원회로부, 유선통신부, RF 회로부 및 안테나부 등으로 구성된다. 무선통신 통합제어부는 ZigBee를 위한 무선통신 제어 기능 및 방사선 측정 및 제어를 위한 기능을 수행한다. 센서 및 고전압 발생부는 2차에 걸쳐 500V의 고전압을 생성하여 GM Tube를 통해 감지된 방사선에 대한 펄스를 증폭 필터링 하는 기능을 수행한다. 충전 및 전원회로부는 리튬이온 배터리의 충전 및 원칩 프로세서에 전원을 공급하는 기능을 수행한다. 유선통신부는 PC와의 인터페이스 및 디버깅을 위한 USB 인터페이스 및 원거리 유선 통신이 가능하도록 RS-485/422 인터페이스 기능을 수행한다. RF 회로부 및 안테나부는 칩안테나를 적용할 수 있도록 RLC 수동소자를 적용하여 BALUN 및 안테나 임피던스 매칭 회로를 구성하여 무선통신이 가능하도록 한다. 제안된 원격 방사선 측정을 위한 ZigBee 원칩형 통신 모듈을 설계 실험한 결과, 10m, 100m 구간에서 모두 데이터가 정상적으로 전송되어서 원격 방사선량 측정이 되었음을 확인할 수가 있었다. 또한 낮은 소비전류와 적은 비용으로 원격 방사선량 측정환경을 구축할 수 있었다. 따라서 방사선 측정장치의 선형성 확보 및 장치의 소형화를 통해 안정적인 방사선 측정 및 실시간 모니터링 환경을 구축할 수가 있었다.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.339-353
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• 2014

A straightforward method for optimal determining of a high frequency inductor's parasitic capacitance is presented. The proposed estimation method is based on measuring the inductor's impedance samples over a limited frequency range bordering on the resonance point considering k-dB deviation from the maximum impedance. An optimized solution to k could be obtained by minimizing the root mean squared error between the measured and the estimated impedance values. The model used to provide the estimations is a parallel RLC circuit valid at resonance frequency which will be transferred to the real model considering the mentioned interval of frequencies. A straightforward algorithm is suggested and programmed using MATLAB which does not require a wide knowledge of design parameters and could be implemented using a spectrum analyzer. The inputs are the measured impedance samples as a function of frequency along with the diameter of the conductors. The suggested algorithm practically provides the estimated parameters of a real inductance model at different frequencies, with or without design information. The suggested work is different from designing a high frequency inductor; it is rather concentration of determining the parameters of an available real inductor that could be easily done by a recipe provided to a technician.

• Current Optics and Photonics
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• 제1권5호
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• pp.529-537
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• 2017

We explored how changes in blood vessel compliance affected the systolic rise time (SRT) of the maximum blood pressure (BP) peak wave and the diastolic fall time (DFT) of the minimal BP peak wave, compared to photoplethysmograpic (PPG) parameters, using a two-compartment, second-order, arterial Windkessel model. We employed earlier two-compartment Windkessel models and the components thereof to construct equivalent blood vessel circuits, and reproduced BP waveforms using PSpice technology. The SRT and DFT values were obtained via circuit simulation, considering variations in compliance (the dominant influence on blood vessel parameters attributable to BP changes). And then performed regression analysis to identify how compliance affected the SRT and DFT. We compared the SRTs and DFTs of BP waves to the PPG values by reference to BP changes in each subject. We confirmed that the time-shift propensities of BP waves and the PPG data were highly consistent. However, the time shifts differed significantly among subjects. These simulation and experimental results allowed us to construct an initial trend curve of individual BP peak time (measured via wrist PPG evaluations at three arm positions) that facilitated accurate individual BP estimations.

• 조명전기설비학회논문지
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• 제29권11호
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• pp.82-88
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• 2015

In recent years, numerous studies have attempted to find and explore the auxiliary brake and the oil pressure type and electrical type are mainly used. However, the model proposed here is to self-excited eddy current brake. The advantage of this is it does not require an external power supply and can be produced to reduce the size than others. This self-eddy current brake consists of RLC circuit so resistance, inductance and capacitance value can be considered a fixed value. But, inductance and resistance value changes depending on the shape, temperature and magnetic alteration. Therefore, in this paper, the focal point is characteristic analysis according to the parameter variations. Also, using this result, this paper explains how to estimate the capacitance.