• Title/Summary/Keyword: in-circuit test

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Modeling of O/E conversion for 40 Gbps WGPD submodule (40Gbps 급 도파로형 광수신소자 submodule의 광전변환특성 모델링)

  • Jeon, Su-Chang;Yun, Il-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.79-80
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    • 2005
  • In this paper, the circuit models of optical to electrical(O/E) characteristics of waveguide photodiode(WGPD) submodule are examined. Test structures of WGPD and WGPD submodule were fabricated and S21 parameter was measured to characterize the O/E conversion property. Valid circuit models were derived by RF circuit simulation and O/E characteristics were modeled to analyze the effects of model parameters on the WGPD submodule performances. Based on the results, it can be concluded that the suggested WGPD submodule model can explain the characteristics of the O/E conversion of WGPD submodule, where the parasitic components originated from ribbon bonding block crucially influence on the performance of WGPD submodule, are able to show more efficient property by making compact bonding structure. We propose an effective WGPD submodule bonding structure and it can ensure the 40Gbps operation of WGPD.

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A Study on the Estimations of Maximum Lift Coefficients of a Light Airplane (경비행기의 최대양력계수 추정에 대한 연구)

  • Lee, Jung-Hoon;Yoo, Si-Yoong
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.762-767
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    • 2008
  • Estimated values for maximum lift coefficients of a light airplane, ChanGong-91, derived from an analytical method using a test database, a computational fluid dynamic method, a wind tunnel test, and a flight test are compared. The DATCOM method and VSAERO code are applied as the analytical method and the computational fluid dynamic method, respectively, in order to estimate the maximum lift coefficients of a light airplane. The wind tunnel test is conducted using a 1/14.5 scaled model installed in a closed circuit type wind tunnel. For the flight test approach, the wings-level power-off stall tests are performed to obtain the maximum lift coefficients. As a point of reference for the flight test results of the maximum lift coefficients, the differences of both estimates derived from the DATCOM method and the wind tunnel test data are smaller than those derived from VSAERO.

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Development and Performance Test of a l00hp HTS Motor

  • Sohn, M.H.;Baik, S.K.;Lee, E.Y.;Kwon, Y.K.;Yun, M.S.;Moon, T.S.;Park, H.J.;Kim, Y.C.;Ryu, K.S.
    • Progress in Superconductivity and Cryogenics
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    • v.6 no.4
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    • pp.27-31
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    • 2004
  • This paper describes the development and fabrication of a high temperature superconducting motor which consists of HTS rotor and air-core stator. The machine was designed for the rated power of 100hp at 1800 rpm. The HTS field windings are composed of the double-pancake coils wound with AMSC's SUS-reinforced Bi-2223 tape conductor. These were assembled on the support structure and fixed by a bandage of glass-fiber composite. The cooling system is based on the heat transfer mechanism of the thermosyphon by using GM cryocooler as cooling source. The cold head is in contact with the condenser of a Ne-filled thermosyphon. The rotor assembly was tested independently at the stationary state and combined with stator. Characteristic parameters such as reactances, inductances, and time constants were determined to obtain a consistent overview of the machine operation properties. This motor has met all design parameters by demonstrating HTS field winding, cryogenic refrigeration systems and an air-core armature winding cooled with air. The HTS field winding could be cooled down below 30K. No-load test of open-circuit characteristics(OCC) and short-circuit characteristics(SCC) and load test with resistive load bank were conducted in generator mode. Maximum operating current of field winding at 30K was 120A. From OCC and SCC test results synchronous inductance and synchronous reactance were 2.4mH, 0.49pu, respectively. Efficiency of this HTS machine was 93.3% in full load(100hp) test. This paper will present design, construction, and basic experimental test results of the 100hp HTS machine.

New On-Chip RF BIST(Built-In Self Test) Scheme and Circuit Design for Defect Detection of RF Front End (RF Front End의 결함 검출을 위한 새로운 온 칩 RF BIST 구조 및 회로 설계)

  • 류지열;노석호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.449-455
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    • 2004
  • This paper presents a novel defect detection method for one chip RF front end with fault detection circuits using input matching measurement. We present a BIST circuit using 40.25{\mu}m$ CMOS technology. We monitor the input transient voltage of the RF front end to differentiate faulty and fault-free RF front end. Catastrophic as well as parametric variation fault models are used to simulate the faulty response of the RF front end. This technique has several advantages with respect to the standard approach based on current test stimulus and frequency domain measurement. Because DUT and fault detection circuits are implemented in the same chip, this test technique only requires use of digital voltmeter (RMS meter) and RF voltage source generator for simpleand inexpensive testing.

A Test System of Valve and Poles for Large Scale Inverter using Resonant Circuit (공진회로를 이용한 대용량 인버터 구성용 밸브 및 폴 시험설비에 관한 연구)

  • Han, Young-Seong;Chung, Chung-Choo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.971-976
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    • 2011
  • This paper proposes a test system for a valve and poles building blocks used for large scale inverters such as STATCOM, SSSC, UPFC and VSC HVDC. Power semiconductors in the valve are normally connected in series to withstand switching voltage much larger than the voltage rating of a single power semiconductor. Therefore, there is a need to verify if the dynamic voltage sharing during switching in a valve is satisfactory. In this paper, we propose a test system that provides the necessary test condition: voltage and current in the valve using resonant circuits. A test scheme for a single phase inverter consisting two poles is also proposed. The performance of the inverter pole has to be verified at the factory test, before the system is installed at the site to secure the reliability of the system. The proposed scheme makes it possible to confirm if the pole can withstand voltage and current switching condition and handle loss.

Study on Real-Time Load Simulator for Testing Propulsion Inverter Test (추진인버터 시험을 위한 실시간 부하 시뮬레이터에 관한 연구)

  • 김길동;신정렬;이우동;한석윤;박기준
    • Journal of the Korean Society for Railway
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    • v.7 no.1
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    • pp.1-8
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    • 2004
  • A newly-built inverter has to undergo a series of stress tests in the final stage of production line. This can be achieved by connecting it to a dynamometer consisting of a three-phase machine joined by a rigid shaft to a DC load machine. The latter is controlled to create some specific load characteristic needed for the test. In this paper a test method is proposed, in which no mechanical equipment is needed. The suggested test stand consists only of a inverter to be tested and a simulator converter. Both devices are connected back-to-back on the AC-side via smoothing reactors. The simulator operates in real-time as an equivalent load circuit, so that the device under test will only notice the behaviour of a three-phase machine under consideration of the load. In oder to prove rightness of the suggested test method, the simulation and actural experiment carried out emulation for a 2.2kW induction motor.

Performance Evaluation of an Automotive Fuel Filter by Multi-Pass Filtration Test (다순환 여과시험에 의한 자동차용 연료필터의 성능 평가)

  • 이재천;장지현
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.6
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    • pp.219-226
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    • 2002
  • Filtration performance of an automotive fuel filter was evaluated based on the theory of Beta ratio. This study also introduced the fuel components' contamination performance test stand incorporating the multi-pass filtration test circuit. The theoretical basis of multi-pass test and test procedure were described in detail. The specification of commercial fuel filter currently available was just the maximum pressure drop across the filter assembly and the holding capacity of contaminants. However, test results revealed that the fuel filter tested could not maintain consistent Beta ratio, that is filtration efficiency, although it had the holding capacity close to the specification. Hence the Beta ratio should be specified in service life. The results also showed that filtration system model should be refined including desorption ratio to estimate the variable Beta ratio in the test.

Prediction of EFT/B Signal Transfer Characteristics in Mobile Charging Circuit (모바일 충전회로에서 EFT/B 신호의 전달특성 예측에 대한 연구)

  • Song, SeungJae;Kim, Kwangho;Jo, Jeongmin;Lee, Seungbae;Kim, So-young;Nah, Wansoo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.10
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    • pp.895-906
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    • 2015
  • This paper presents a methodology and a model that can analyze the high frequency transfer characteristics from socket in the AC power port to the 5 V DC output port in the mobile charging circuit. This is to predict the output signals coming from the IEC(International Electrotechnical Commission) Standard(IEC 61000-4-4), EFT/B(Electric Fast Transient and Burst) immunity test for mobile charging circuit. Since the mobile charging circuit is energized from the AC power socket from the power line, it is necessary to know the high frequency transfer characteristics with activated AC power line. A simple CDN(Coupling-Decoupling Network) is designed and manufactured for measuring S-parameters of mobile charging circuit with and without AC power line activated. The result shows that the S-parameters of the specific mobile charging circuits are almost the same, independent of AC power line activation. Consequently, the S-parameters without AC line could be used to predict the output response to the EFT/B signals, and it was shown that the proposed methodology predicts the output responses quite accurately, which proves the validness of the methodology presented in this paper.

Conceptual Study of a Low-Speed Wind Tunnel for Performance Test of Wind Turbine (풍력터빈 성능시험을 위한 저속풍동 개념연구)

  • Kang, Seung-Hee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.19 no.4
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    • pp.24-29
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    • 2011
  • Conceptual study of an open-circuit type low-speed wind tunnel for performance test of wind turbine blade and airfoil is conducted. The tunnel is constituted of a settling chamber, a contraction, closed test section, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The contraction ratio is 9 to 1 and maximum speed in the test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine and airfoil.

Efficient robust path delay fault test generation for combinational circuits using the testability measure (테스트 용이도를 이용한 조합회로의 효율적인 로보스트 경로 지연 고장 테스트 생성)

  • 허용민;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.2
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    • pp.205-216
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    • 1996
  • In this paper we propose an efficient robust path delay fault test genration algorithm for detection of path delay faluts in combinational ligic circuits. In the proposed robust test genration approach, the testability measure is computed for all gates in the circuit under test and these computed values are used to genrate weighted random delay test vetors for detection of path delay faults. For genrated robust test vectors, we perform fault simulation on ISCAS '85 benchmark circuits using parallel pattern technqieus. The results indicate that the proposed test genration method not only increases the number of detected robust path delay faults but also reduces the time taen to genrate robust tests.

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