Applied Mechanics and Materials Vols. 548-549

Abstract: T501 is an antioxidant widely used in transformer oil. The content of T501 in transformer oil can be detected by electrochemical techniques, however, in the process of condition optimizing for electrochemical measurement, people haven’t done in-depth study the effect of working electrode on T510 antioxidant electrochemical measurement. This paper mainly introduced the alternative working electrodes for the determination of the antioxidant content. Through researching the electrochemical properties of T501 antioxidant by the electrochemical workstation, it is confirmed that the graphite electrode is the best working electrode in the electrochemical measurement of T501 antioxidant content.

Abstract: The reduced-order small-signal model and controller design of a two-transistor forward converter（TTFC）are presented in this paper. First, the small-signal circuit model and transfer function of control to output are found for the TTFC. Then by finding dominant energy poles of the transfer function, the model reductions are performed and the controller design of the converter is simplified. The effective of the proposed model reduction and controller design are demonstrated by bode plots and experimental results.

Abstract: A new automated-switching precision decade capacitor for applications in industries was designed and tested. By using coaxial microwave switches, the automated-switching precision decade capacitor can be automatically set by electrical TTL signals controlled by a computer. To prevent capacitance from drifting caused by variations of ambient temperature, the internal temperature of the automated-switching precision decade capacitor was effectively kept constant using a temperature-controlled oven with sufficiently thermal isolation. Furthermore, to fulfil the compact-size requirement for using at a high frequency, SMD capacitors with NP0 dielectric were used. The temperature stabilities and linearity of the automated-switching precision decade capacitor are presented in this paper.

Abstract: The radiated field of a horizontal ELF Line-current antenna on the inhomogeneous anisotropic ground is analyzed. Influence of inhomogeneous anisotropic ground conductivity upon the directivity of the antenna is researched. The disposal criterion of the antenna path on the inhomogeneous anisotropic ground is given. The skewed angle of the maximal radiant direction of the antenna is calculated. The results have been validated.

Abstract: In Taiwan light source (TLS), Bira’s MCOR30 power converter modules are adopted as the corrector magnet power converters, the output is regulated by analog PWM IC that caused nonlinear behavior at zero cross and the adjustment of compensator for different kind of magnet load is inconvenient. To fulfill digital regulation control, the analog regulation IC of Bira’s MCOR30 is replaced by a fully digital regulation control circuit. With plugging the homemade fully digital regulation control card into MCOR30 that the current sensing component is a shunt that save cost of the power converter, the switching losses and output current ripple were reduced and stability of output current is improved. With the fully digital regulation control circuit, the parameters of the compensator for different magnet load are very easy to adjust. In addition, the feasibility and validity of MOSFET switching algorism is simulated with MATLAB Simulink and the performance of this power converter is verified, the output current ripple of this power converter could be within 10ppm, which is beyond the requirement of current TLS corrector power converter and qualified to be used in the future TPS facility.

Abstract: The paper deals with the description of complex monitoring system for remote monitoring of thermal processes, concentration of toxic gases and dustiness of the atmosphere. Each of these quantities is measured and consequently processed by use of wireless modules communicating with supervisor system. It presents design of communication among particular sensors and further data processing and transfer to the dispatching center.

Abstract: In this thesis, we take STM32F103R8T6 as main chip, SH79F32 as auxiliary chip, the temperature sensor of DS18B20 as collection tools, wireless transceiver based on nRF905 as communication tool, and reach the function of wireless sensor networks. Through Altium Designer Release 10 to conduct schematic design and draw PCB, and then solder circuit boards, use the software of Keil to design process, to realize wireless sensor communication between different microcontrollers, after that ,complete the design and production of wireless sensor communications platforms.

Abstract: The paper briefly reviews the domestic and overseas lightning electromagnetic field data acquisition system, and the data transfer rate and data transfer approaches of lightning. Lightning data transfer approaches includes the conventional transmission systems of data collection, and three data transmission means which including the use of power system network to transmit data, the use of the Internet to transmit data and the use of satellite communications to expand the range of distribution.

Abstract: In modern electronic systems, data rate is keeping increase, and Gbps becomes common, designing for reliable signal integrity becomes more and more important. In the high speed borad/package design, discontinuities are big concerns of signal integrity. A variety of sources lead to discontinuities and every source ought to be carefully treated. The signal via is one source of discontinuity that should not be overlooked. Vias can add jitter and reduce eye openings that can cause data misinterpretation by the receiver. This paper detail the antipad, pad and excess via stub effect on the vias. In each case, the impedance mismatch at the via transition can be minimized by optimizing a few parameters such as antipad radius, pad radius and excess via stub. The impacts of these parameters are investigated with the help for a full-wave 3D electromagnetic simulator.

Abstract: This paper presents a study of melting current in the commercial glass tube fuses to determine the duration of melt, maximum melting current and maximum power consumption of the fuse in a blowing circuit. A microcontroller is used as a device to measure and collect the values of current, voltage, and power consumption. In the experiments, the glass tube fuses rated of 0.5 A, 1 A, 2 A, 3 A, 5 A, 10 A, 15 A, and 20 A were used. The experimental results show that the melting time were approximately 0.05 s, 0.07 s, 0.11 s, 0.13 s, 0.18 s, 0.20 s, 0.28 s, and 0.40 s; the maximum of melting current were approximately 0.66 A, 1.17 A, 3.81 A, 13.77 A, 20.80 A, 25.05 A, 26.66 A, and 29.96 A; the maximum of blowing voltage were approximately 12.25 V, 12.25 V, 12.30 V, 12.15 V, 12.10 V, 12.29 V, 12.10 V and 12.20 V; and the maximum of blowing power consumption were approximately 7.53 W, 14.22 W, 45.57 W, 158.49 W, 224.38 W, 242.21 W, 230.63 W and 283.68 W respectively.