Factors affecting the reliability of low voltage aerial bundle cable systems

1995 ◽  
Author(s):  
D. Birtwhistle
Keyword(s):  
Low Voltage ◽  
Factors Affecting ◽  
Cable Systems

scholarly journals Optimization of Bi2O3, TiO2, and Sb2O3Doped ZnO-Based Low-Voltage Varistor Ceramic to Maximize Nonlinear Electrical Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Masoumeh Dorraj ◽  
Azmi Zakaria ◽  
Yadollah Abdollahi ◽  
Mansor Hashim ◽  
Seyedehmaryam Moosavi
Keyword(s):  
Low Voltage ◽  
Quadratic Model ◽  
Molar Ratio ◽  
Sintering Process ◽  
Spinel Type ◽  
Factors Affecting ◽  
Milling Method ◽  
Level 3 ◽  
Central Composite ◽  
Good Agreement

In ZnO-based low voltage varistor, the two essential features of microstructure determining its nonlinear response are the formation Bi-enriched active grain boundaries as well as a controlled ZnO grain size by secondary spinel-type phases. Besides, the microstructure and phase composition are strongly affected by the dopant concentration during sintering process. In this study, the optimal dopant levels of Bi2O3, TiO2, and Sb2O3to achieve maximized nonlinear electrical property (alpha) were quantified by the response surface methodology (RSM). RSM was also used to understand the significance and interaction of the factors affecting the response. Variables were determined as the molar ratio of Bi2O3, TiO2, and Sb2O3. The alpha was chosen as response in the study. The 5-level-3-factor central composite design, with 20 runs, was used to conduct the experiments by ball milling method. A quadratic model was established as a functional relationship between three independent variables and alpha. According to the results, the optimum values of Bi2O3, TiO2, and Sb2O3were obtained 0.52, 0.50, and 0.30, respectively. Under optimal conditions the predicted alpha (9.47) was calculated using optimal coded values from the model and the theoretical value is in good agreement with the value (9.43) obtained by confirmation experiment.

scholarly journals Analysis of the Degradation of MOSFETs in Switching Mode Power Supply by Characterizing Source Oscillator Signals

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xueyan Zheng ◽  
Lifeng Wu ◽  
Yong Guan ◽  
Xiaojuan Li
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Nuclear Power ◽  
Low Voltage ◽  
Junction Temperature ◽  
Factors Affecting ◽  
Die Attach ◽  
Switching Mode Power Supply ◽  
Switching Mode ◽  
State Resistance

Switching Mode Power Supply (SMPS) has been widely applied in aeronautics, nuclear power, high-speed railways, and other areas related to national strategy and security. The degradation of MOSFET occupies a dominant position in the key factors affecting the reliability of SMPS. MOSFETs are used as low-voltage switches to regulate the DC voltage in SMPS. The studies have shown that die-attach degradation leads to an increase in on-state resistance due to its dependence on junction temperature. On-state resistance is the key indicator of the health of MOSFETs. In this paper, an online real-time method is presented for predicting the degradation of MOSFETs. First, the relationship between an oscillator signal of source and on-state resistance is introduced. Because oscillator signals change when they age, a feature is proposed to capture these changes and use them as indicators of the state of health of MOSFETs. A platform for testing characterizations is then established to monitor oscillator signals of source. Changes in oscillator signal measurement were observed with aged on-state resistance as a result of die-attach degradation. The experimental results demonstrate that the method is efficient. This study will enable a method to predict the failure of MOSFETs to be developed.

scholarly journals Experimental design of fuse link with ceramic alloy: Cracking problem

2014 ◽  
Vol 68 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Murat Şanyılmaz ◽  
Sermin Elevli
Keyword(s):  
Compressive Strength ◽  
Experimental Design ◽  
Low Voltage ◽  
Performance Criteria ◽  
Factors Affecting ◽  
Industrial Buildings ◽  
Initial Stage ◽  
Full Factorial Experimental Design ◽  
Main Effects ◽  
Full Factorial

Low-voltage (LV) fuse systems, which open a circuit by cutting the current when it exceeds a given value for an adequate period, are used in nonresidential, commercial, and industrial buildings. LV-fuse systems consist of a fuse base, fuse link, and a detachable operating handle. The fuse link is made of a ceramic alloy. In this study, a full-factorial experimental design with two levels was used to solve the fracture problem of fuse links. In this scope, performance criteria (compressive strength), factors affecting the performance criteria (moisture ratio, shaping duration, drying duration, and firing duration) and factor levels were determined in the initial stage. Main effects and interactions among factors were investigated, and factor-level combinations that maximize the compressive strength were determined according to results of analysis. Finally, the relationship between compressive strength and experimental factors was presented in the form of f = y(x) for prediction purposes.

The Measurement of Carpet Static

1976 ◽  
Vol 46 (2) ◽  
pp. 129-134 ◽  
Author(s):  
K. Chakravarti ◽  
G. J. Pontrelli
Keyword(s):  
Low Voltage ◽  
Fiber Type ◽  
Threshold Level ◽  
Test Methods ◽  
Discharge Voltage ◽  
Test Method ◽  
Static Test ◽  
Factors Affecting ◽  
Static Sensitivity ◽  
Maximum Voltage

The various factors affecting static generation in carpets such as relative humidity, fiber type, shoe-sole material, carpet backing, and treadwear have been examined in this paper. Experiments to determine threshold level of static sensitivity in humans have been made. Critical evaluations of current carpet static test methods have been made, and the use of low voltage (discharge voltage) instead of maximum voltage value is suggested. A new carpet static test method using a motorized treadmill device has been described.

Test Point Switch in Low Voltage Electrical Transient Performances Detection Technical Improvement Methods

2013 ◽  
Vol 394 ◽  
pp. 274-277
Author(s):  
Xiang Yang Du ◽  
Cong Jia ◽  
Chao Xu
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Circuit Breaker ◽  
Test Point ◽  
Production Test ◽  
Technical Improvement ◽  
Theoretical Derivation ◽  
Experimental Proof ◽  
Factors Affecting ◽  
Contact Switch

This article introduces, in low voltage circuit breaker on the switch instantaneous performance detecting station, in order to adapt to the requirement of modern high-speed automated production test, the main factors affecting the detection speed - switch measurement point method is studied, the improvement, the existing method of "contact switch" to replace "non-contact switch method, through theoretical derivation and experimental proof, proved that the new method is feasible and economical.

Factors Affecting the Clinical Outcome of Low-Voltage Electrical Injuries in Children

2013 ◽  
Vol 29 (3) ◽  
pp. 357-359 ◽  
Author(s):  
Mehmet Tahir Gokdemir ◽  
Halil Kaya ◽  
Özgür Söğüt ◽  
Muazez Cevik
Keyword(s):  
Clinical Outcome ◽  
Low Voltage ◽  
Factors Affecting ◽  
Electrical Injuries

Factors affecting selection, installation and coordination of surge protective devices for low voltage systems

2014 ◽  
Vol 113 ◽  
pp. 220-227 ◽  
Author(s):  
T. Kisielewicz ◽  
G.B. Lo Piparo ◽  
F. Fiamingo ◽  
C. Mazzetti ◽  
B. Kuca ◽  
...  
Keyword(s):  
Low Voltage ◽  
Factors Affecting ◽  
Protective Devices

Factors Affecting the Performance of Backscattered Electron Detectors at Low Beam Accelerating Voltages in SEM

1998 ◽  
Vol 4 (S2) ◽  
pp. 252-253
Author(s):  
V N E Robinson
Keyword(s):  
Atomic Number ◽  
Low Voltage ◽  
Beam Current ◽  
Dead Layer ◽  
Factors Affecting ◽  
Backscattered Electron ◽  
Improved Performance ◽  
Contrast Information ◽  
Image Position ◽  
Z Contrast

The use of backscattered electron (BSE) imaging in low voltage scanning electron microscopy (SEM) has increased over the past few years. This appears to be due to several factors including improved performance of SEMs at low voltages, reduced beam penetration, more reliable metrology, improved atomic number (Z) contrast information (for low Z) and reduced charging artefacts over secondary electron (SE) imaging. Understanding the factors involved in low voltage BSE detection may assist in improving the information attainable.It has been shown that the signal Sdet from a BSE detector, for EB ≫ Ew is given bywhere η is the BSE yield, Ω is the solid angle subtended by the detector to the specimen, D is the internal conversion efficiency of the detector, EB is beam accelerating voltage, Ew is the energy barrier of the dead layer on the detector's surface, IB is the beam current, F(Z) and F(Ω) are functions which take into account the variation of BSE energy with atomic number Z and collection angle respectively.

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