• 전자공학회논문지SC
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• 제40권4호
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• pp.275-281
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• 2003

0.5㎛ 2중 폴리 CMOS 공정을 이용하여 새로운 뉴럴 오실레이터를 설계, 제작하였다. 제안하는 뉴럴 오실레이터는 트랜스콘덕터 및 캐패시터와 비선형 가변 부성저항으로 이루어진다. 뉴럴 오실레이터의 입력단으로 사용되는 비선형 가변 부성저항은 정귀환의 트랜스콘덕터와 가우시안 분포의 전류전압 특성을 지니는 범프 회로를 이용하여 구현하였다. 또한 SPICE 모의실험을 통하여 제안한 오실레이터의 특성분석 후 집적회로 설계를 실시하였다. 한편 흥분성 및 억제성 시냅스로 연결된 4개의 뉴럴 오실레이터로 간단한 신경회로망을 구성하여 그 특성을 확인하였다. 집적회로로 제작된 뉴럴 오실레이터에 대하여 ± 2.5 V 전원 조건하에서 측정된 결과를 분석하고 모의실험 결과와 비교한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.81-84
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• 2004

The NiCr is an important material for present thin-film resistor application owing to its low TCR and thermal stability. In this work, the NiCr thin films were deposited on coming glass substrate by reactive magnetron sputtering and the annealing at temperatures range from 300 to $500^{\circ}C$ for 20 min in vacuum. X-ray, AFM, $R_s$(surface leakage current) have been used to study the structural and electrical properties of the NiCr thin films. The high precision NiCr thin films resistor with TCR(temperature coefficient of resistance) of less then $10\;ppm/^{\circ}C$ was obtained under in in-situ annealing at $300^{\circ}C$ on Cr buffer layer substrate. It is clear that the NiCr thin-films resistor electrical properties are low TCR related with it's annealing and buffer layer condition. NiCr thin film resistor having a good thermal stability and low TCR properties are expected for the application to the dielectric material of passive component.

• 센서학회지
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• 제25권2호
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• pp.131-137
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• 2016

In this study, a multilevel visible light communication (VLC) system based on resistor ladder circuit is designed to transmit medical data. VLC technology is being considered as an alternative wireless communication due to various advantages such as ubiquity, license free operation, low energy consumption, and no radio frequency (RF) radiation characteristics. With VLC even in places where traditional RF communication (e.g., Wi-Fi) is forbidden, significant bio-medical signal including the electrocardiography (ECG) and photoplethysmography (PPG) data can be transmitted. More lives could be saved anywhere by this potential advantage of VLC with a fast emergency response time. A multilevel transmission scheme is adopted to improve the data capacity with keeping simplicity, where data transmission rate can increase by log2m times (m is the number of voltage levels) than that of conventional VLC transmission based on on/off keying. In order to generate multi-amplitudes, resistor ladder circuit, which is a basic principle of digital to analog convertor, is employed, and information is transferred through LED (Light-Emitting Diode) with different voltage level. In the receiver side, multilevel signal is detected by optical receiver including a photo diode. Then, the collected data are analyzed to serve the necessary medical care to the concerned patient.

• 전자공학회논문지SC
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• 제40권6호
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• pp.16-23
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• 2003

본 논문에서 보청기를 위한 개별 BJT 소자의 효과적인 바이어스 회로를 제안한다. 보청기에 널리 사용되는 컬렉터 귀환 바이어스 회로는 부귀환 저항을 가지고 있다. 이 저항은 AC와 DC에 동시에 영향을 줌으로서 DC 바이어스 점의 변화 없이 증폭기의 이득을 변화시키기 어렵다. 또한 기존회로는 보청기의 이득이 높을 경우 전원 잡음의 정귀환으로 발진할 수 있는 단점이 있다. 제안된 회로는 컬렉터 귀환 바이어스회로에 베이스와 전원 사이에 컬렉터 저항보다 β배 더 큰 저항을 추가하여 기존회로의 두 가지 단점을 줄일 수 있다. 제안된 회로에서 DC 바이어스 점의 변화 없이 증폭기의 이득을 변경 할 수 있고 모의실험에서 기존회로보다 전원 잡음 이득을 18.5%정도 감소시킬 수 있다.

• 전기학회논문지
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• 제67권8호
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• pp.1055-1061
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• 2018

Recently, due to the rapid development of electric vehicle and energy storage system, it is emphasized for battery management system to be needed and to be improved. BMS carries out various movement for optimization the use of the energy and safe use of secondary battery, these movement of BMS start at high wattage shunt fixed resistor which performs a function for detecting current among the BMS components. In addition, for the safe operation of secondary battery, the reliability of current voltage variation detected from shunt should be secured, and for corresponding characteristics, the quality of Temperature coefficient of resistance for BMS shunt and the quality of Thermo electromotive force all must be excellent. For these reasons, this study comes up with the stabilization plan for thermo electromotive force and temperature coefficient of resistance of BMS shunt resistor which is key to secondary battery operation.

• 한국조명전기설비학회지:조명전기설비
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• 제7권1호
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• pp.30-36
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• 1993

본 연구는 정류기의 입력전류에 포함되어 있는 고조파성분을 제거하고 입력역률을 개선하기 위해 무손실 저항(Loss Free Resistor) 개념에 기본을 둔, PC, 가전기기 및 형광등용 전자안정기등과 같은 저전력 전원설비에 적합한 불연속 도통모드(DCM) 플라이백 방식의 능동역률 보정기의 등가회로모델 및 설계법을 제시하였다. 이 개념에 의하여 능동역률 보정기의 등가입력저항, 출력전력원 특성을 정확하게 나타낼 수 있었으며 또 설계방정식을 유도하여 능동역률 보정기를 설계 시험한 결과, 적은 부품으로 정류기의 입력교류 전류에 포함되어 있는 고주파를 제거하였고 따라서 0.98의 고입력역률의 정류를 할 수 있었다.

• 센서학회지
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• 제19권6호
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• pp.483-489
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• 2010

Display quality depends on panel temperatures. To compensate it, temperature sensor was integrated on the panel. The conventional temperature sensor integrated on the panel needs external reference resistor. Since the resistance of external resistor can vary according to the variation of the environment temperature, the conventional temperature sensor can make error in temperature sensing. The environmental temperatures can change by the back light unit, driving circuits or chips. In this paper, we proposed a integrated temperature sensor on display panel which does not need external reference resister. Instead of external reference resistor, we used two materials which have different temperature coefficient in resistivity. They are connected serially and the output voltage was measured at the point of connection with the applied voltage to both ends. The proposed sensor was fabricated with indium tin oxide(ITO), and Mo metal electrode temperature sensor which were connected serially. We verified the temperature senor by the measurements of sensitivity, lineality, hysteresis, repeatability, stability, and accuracy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.98-99
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• 2007

This study has successfully demonstrated the direct fabrication of polymer resistors using ink-jet printing technology as an alternative patterning to traditional photolithography. The polymer resistors were fabricated just by two layer processes using a ink-jet printer (DMP-2800, Fujifilm Dimatix). First, resistive materials was patterned by a ink-jet printing with the desired width and length. Next, resistor fabrication was completed by printing metal contact pads on the both sides of the polymer resistor. We used poly (3,4-ethylene dioxythiophene) poly(styrenesulfonate)(PEDOT:PSS) for the resistor material and a nano-sized silver colloid for the metal contact pads. We characterized the electrical properties of PEDOT:PSS by measuring sheet resistance and specific resistance on a glass substrate. From analysis of the measured resistances, the electrical resistances of the polymer resistors linearly increased as a function of printed width and length of resistors. The accuracy of the fabricated polymer resistor showed about $0.6{\sim}2.5%$ error for the same dimensions.

• 전력전자학회논문지
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• 제17권5호
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• pp.416-422
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• 2012

This paper proposes a low power-loss current measurement using a resistor and bypass switch. Conventional current sensing method using a resistor has a disadvantage of power loss which degrades the efficiency of the entire systems. On the other hand, proposed measurement technique operating with bypass-switch connected in parallel with sensing resistor can reduce power loss significantly the current sensor. The propose measurement works for discrete-time sampling of current sensing. Even while the analog-digital conversion does not occur at the controller, the sensing voltage across the sensor still causes ohmic conduction loss without information delivery. Hence, the bypass switch bypasses the sensing current with a small amount of power loss. In this paper, a 90[W] prototype hardware has been implemented for photovoltaic MPPT experimental verification of the proposed low power-loss current measurement technique. From the results, it can be seen that PV power observation is successfully done with the proposed method.

• Journal of Power Electronics
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• 제19권6호
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• pp.1467-1476
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• 2019

Grid unbalanced faults can cause core saturation of power transformer and produce lower-order harmonics. These issues increase the electrical stress of power electronic devices and can cause a tripping of an entire HVDC system. In this paper, based on the positive-sequence and negative-sequence impedance model of a VSC-HVDC system as seen from the point of common connection (PCC), the resonance problem is analyzed and the factors determining the resonant frequency are obtained. Furthermore, to suppress over-voltage and over-current during resonance, a novel method using a virtual harmonic resistor is proposed. The virtual harmonic resistor emulates the role of a resistor connected in series with the commutating inductor without influencing the active and reactive power control. Simulation results in PSCAD/EMTDC show that the proposed control strategy can suppress resonant over-voltage and over-current. In addition, it can be seen that the proposed strategy improves the safety of the VSC-HVDC system under unbalanced faults.