The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Xiaoyan Zeng - One of the best experts on this subject based on the ideXlab platform.
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Study on thick film Resistor and electrode fabricated by laser micro-cladding electronic pastes
Surface and Coatings Technology, 2006Co-Authors: Xiaoyan ZengAbstract:Nowadays, electronic devices are required to be smaller, to have a high-density integration and to be of lower cost. In order to meet the developing demands, some new techniques have appeared in recent years. In this paper, a technique named laser micro-cladding electronic pastes is used to fabricate the thick film Resistor and electrode units on insulator substrates without using a mask. The results demonstrate that the high-quality Resistors could be fabricated by laser micro-cladding. However, the processing steps are very important since they have significant effects on the surface finish, the extent of diffusion between electrode film and Resistor film, and on the reliability of the Resistors. Laser micro-cladding electronic pastes may become a novel technique to fabricate high quality conductive lines (electrodes) and Resistors with good properties that will come into industrial application in the future.
Ilia Voloh - One of the best experts on this subject based on the ideXlab platform.
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online neutral grounding Resistor monitoring for unit connected generators with hardware validation
International Journal of Electrical Power & Energy Systems, 2019Co-Authors: Rahim Jafari, Mital Kanabar, T S Sidhu, Ilia VolohAbstract:Abstract Neutral grounding Resistors are used to control transient overvoltages and overcurrents in power systems. Failure of these critical assets revives many disadvantages of ungrounded and solidly grounded traditional systems. Therefore, monitoring the neutral grounding Resistors is necessary. A new continuous monitoring technique is proposed for such a Resistor located at the neutral of unit-connected generators. It detects Resistor failure by comparing the third harmonic of neutral and residual voltages. This proposed scheme demonstrates reliable operation under various conditions of the system and Resistor as observed by PSCAD in conjunction with MATLAB. Further performance validation has been carried out using an industrial generator protection relay as well. In contrast to existing methods, this scheme does not require any additional measurement instruments. Thereby, it is easily retrofitted to installed unit-connected generator protection infrastructures. Moreover, this continuous monitoring technique prevents maloperation of the generator stator ground protection due to the neutral grounding Resistor failure.
T S Sidhu - One of the best experts on this subject based on the ideXlab platform.
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online neutral grounding Resistor monitoring for unit connected generators with hardware validation
International Journal of Electrical Power & Energy Systems, 2019Co-Authors: Rahim Jafari, Mital Kanabar, T S Sidhu, Ilia VolohAbstract:Abstract Neutral grounding Resistors are used to control transient overvoltages and overcurrents in power systems. Failure of these critical assets revives many disadvantages of ungrounded and solidly grounded traditional systems. Therefore, monitoring the neutral grounding Resistors is necessary. A new continuous monitoring technique is proposed for such a Resistor located at the neutral of unit-connected generators. It detects Resistor failure by comparing the third harmonic of neutral and residual voltages. This proposed scheme demonstrates reliable operation under various conditions of the system and Resistor as observed by PSCAD in conjunction with MATLAB. Further performance validation has been carried out using an industrial generator protection relay as well. In contrast to existing methods, this scheme does not require any additional measurement instruments. Thereby, it is easily retrofitted to installed unit-connected generator protection infrastructures. Moreover, this continuous monitoring technique prevents maloperation of the generator stator ground protection due to the neutral grounding Resistor failure.
Nedjeljko Lekic - One of the best experts on this subject based on the ideXlab platform.
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Binary Weighted DAC with 2-ξ Resistor Ratio
Spolecnost pro radioelektronicke inzenyrstvi, 2018Co-Authors: Nedjeljko Lekic, R. Dragovic-ivanovic, Zoran Mijanovic, Lj. StankovicAbstract:In this paper we present a new digital analog converter (DAC) design, based on the binary weighted Resistor network. The proposed design ensures high conversion accuracy using low precision Resistors with ±1% ±2%, ±5%, ±10% and ±20% Resistor tolerance. High accuracy is achieved due to better coverage of the analog domain of the transfer characteristic. In binary weighted converters the imprecision of Resistors introduces positive and negative differential nonlinearities (DNL). Positive DNL causes gap in the analog domain of the transfer characteristic and negative DNL causes non-monotonicity. In the proposed solution we change the Resistor ratio of the two consecutive DAC branches from 2 to 2-ξ, where ξ is small positive number. With this change, we intentionally introduce an additional negative DNL in order to entirely avoid the positive gap. Simulation results confirm that even with Resistors tolerance of up to ±10%, we can achieve a converter with maximal gap in the transfer characteristic less than or around one LSB
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Optimal Resistor ratio in the DAC with low precision Resistors $statistical approach
9th International Conference on Electronics Circuits and Systems, 2002Co-Authors: R. Dragovic-ivanovic, Zoran Mijanovic, L Jubisa Stankovic, Nedjeljko LekicAbstract:The widely used digital-analog converter is the one with 2R/R ladder circuit. It can be easy realized as an integrated circuit, but accurate input-output characteristic require extremely precise Resistors. With the laser trimming technology it is possible to improve converter accuracy, but aging and environmental factors decrease linearity and overall accuracy of a converter, thus reducing the usable life and the converter applicability. We propose a new DAC design based on 2R/sup +//R ladder circuit, where a high precision is obtained due to better coverage of analog range at the transfer characteristic (even for low precision Resistors, ex. 1%, 2% and 5% Resistor tolerance). Statistical method shows that various allowed tolerances of the circuit Resistors are associated with various optimal Resistor ratios in an 2R/sup +//R circuit.
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ICECS - Optimal Resistor ratio in the DAC with low precision Resistors $statistical approach
9th International Conference on Electronics Circuits and Systems, 1Co-Authors: R. Dragovic-ivanovic, Zoran Mijanovic, L Jubisa Stankovic, Nedjeljko LekicAbstract:The widely used digital-analog converter is the one with 2R/R ladder circuit. It can be easy realized as an integrated circuit, but accurate input-output characteristic require extremely precise Resistors. With the laser trimming technology it is possible to improve converter accuracy, but aging and environmental factors decrease linearity and overall accuracy of a converter, thus reducing the usable life and the converter applicability. We propose a new DAC design based on 2R/sup +//R ladder circuit, where a high precision is obtained due to better coverage of analog range at the transfer characteristic (even for low precision Resistors, ex. 1%, 2% and 5% Resistor tolerance). Statistical method shows that various allowed tolerances of the circuit Resistors are associated with various optimal Resistor ratios in an 2R/sup +//R circuit.
Li Xiang-you - One of the best experts on this subject based on the ideXlab platform.
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A preliminary study on Resistor direct preparation by laser micro-cladding Resistor pastes on ceramic substrate
Laser Technology, 2005Co-Authors: Li Xiang-youAbstract:A new te chnology to prepare thick film Resistors directly by laser micro-cladding resis tor pastes on ceramic substrate is introduced.The preliminary result of the expe riment is given.Some line Resistors and some special Resistors overlapped are fa bricated successfully.Also the mechanisms of Resistors formation are analyzed.Ma inly the influence of parameters is discussed.The effects of coating thickness, laser power and laser scanning speed on Resistor line width are studied in detai l.
