Reliability Analysis

Author(s):  
Cherry Bhargava

As the integration of components are increasing from VLSI to ULSI level. This may lead to damage of electronic system because each component has its own operating characteristics and conditions. So, health prognostic techniques are used that comprise a deep insight into failure cause and effects of all the components individually as well as an integrated technique. It will raise alarm, in case health condition, of the components drift from the desired outcomes. From toy to satellite and sand to silicon, the major key constraint of designing and manufacturing industry are towards enhanced operating performance at less operating time. As the technology advances towards high-speed and low-cost gadgets, reliability becomes a challenging issue.

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 586
Author(s):  
Jincheng Liu ◽  
Jiguang Yue ◽  
Li Wang ◽  
Chenhao Wu ◽  
Feng Lyu

As the core of electronic system, the switched-mode power supply (SMPS) will lead to serious accidents and catastrophes if it suddenly fails. According to the related research, the monitoring of ripple can acquire the health degree of SMPS indirectly. To realize low-cost, high-precision, and automatic ripple measurement, this paper proposes a new ripple voltage (peak-to-peak value) measuring scheme, utilizing a DAC and two high-speed comparators. Within this scheme, the DC component of SMPS output is blocked by a high-pass filter (HPF). Then, the filtered signal and the reference voltage from a DAC together compose the input of a high-speed comparator. Finally, output pulses of the comparator are captured by a microcontroller unit (MCU), which readjusts the output of the DAC by calculation, and this process is repeated until the DAC output is exactly equal to the peak (or valley) value of ripple. Moreover, in order to accelerate the measurement process, a peak estimation method is specially designed to calculate the output ripple peak (or valley) value of buck topology through merely two measurements. Then the binary search method is utilized to obtain a more exact value on the basis of estimative results. Additionally, an analysis of the measurement error of this ripple measurement system is executed, which shows that the theoretical error is less than 0.5% where the ripple value is larger than 500 mV. Furthermore, appropriate components are selected, and a prototype is manufactured to verify the validity of the proposed theory.


Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2822
Author(s):  
Rocco Crescenzi ◽  
Giuseppe Vincenzo Castellito ◽  
Simone Quaranta ◽  
Marco Balucani

Gyroscopes are one of the next killer applications for the MEMS (Micro-Electro-Mechanical-Systems) sensors industry. Many mature applications have already been developed and produced in limited volumes for the automotive, consumer, industrial, medical, and military markets. Plenty of high-volume applications, over 100 million per year, have been calling for low-cost gyroscopes. Bulk silicon is a promising candidate for low-cost gyroscopes due to its large scale availability and maturity of its manufacturing industry. Nevertheless, it is not suitable for a real monolithic IC integration and requires a dedicated packaging. New designs are supposed to eliminate the need for magnets and metal case package, and allow for a real monolithic MEMS-IC (Integrated Circuit) electronic system. In addition, a drastic cost reduction could be achieved by utilizing off-the-shelf plastic packaging with lead frames for the final assembly. The present paper puts forward the design of a novel tri-axial gyroscope based on rotating comb-drives acting as both capacitive sensors and actuators. The comb-drives are comprised of a single monolithic moving component (rotor) and fixed parts (stators). The former is made out of different concentrated masses connected by curved silicon beams in order to decouple the motion signals. The sensor was devised to be fabricated through the PolyMUMPs® process and it is intended for working in air in order to semplify the MEMS-IC monolithic integration.


2012 ◽  
Vol 150 ◽  
pp. 144-147 ◽  
Author(s):  
Wei Yu Zhang ◽  
Ying Ruan ◽  
Xiao Yan Diao ◽  
Huang Qiu Zhu

To fulfil the objective of high speed, high precision and intelligence in the modern equipment and advanced manufacturing industry, the magnetic bearing is requested to have small volume, low cost and low consumption. In this paper, an AC-DC three-degree-of-freedom hybrid magnetic bearing (AC-DC-3DOF-HMB) is studied, which integrates radial bearing and axial bearing in one of the magnetic bearing. The configuration and principle of AC-DC-3DOF-HMB are expounded, and the mathematical models of suspension forces are given. Then based on the function block diagram of AC-DC-3DOF-HMB control system, its hardware and software configuration are designed. The experiment results show that the rotor can be suspended stably with three degrees of freedom and has a good performance in anti- interference, and the feasibility of the control system design can be verified.


Author(s):  
Hussain Attia ◽  
Ali Sagafinia

This paper presents an electronic design based on general purpose discrete components for speed control of a single phase induction motor drive. The MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse Width Modulation (SPWM) techniques with V/F method based on Voltage Controlled Oscillator (VCO). The load power is also controlled by a novel design to produce a suitable SPWM pulse. The proposed electronic system has ability to control the output frequency with flexible setting of lower limit to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the proposed controller able to control the value of load voltage to frequency ratio, which plays a major parameter in the function of IM speed control. Furthermore, the designed system is characterized by easy manufacturing and maintenance, high speed response, low cost, and does not need to program steps as compared to other systems based on Microcontroller and digital signal processor (DSP) units. The complete proposed electronic design is made by the software of NI Multisim version 11.0 and all the internal sub-designs are shown in this paper. Simulation results show the effectiveness of electronic design for a promising of a high performance IM PWM drive.


2011 ◽  
Vol 305 ◽  
pp. 25-30 ◽  
Author(s):  
Xiao Jun Wang ◽  
Wen Hui Yue ◽  
Zi Qiang Han

As a sustainable model of modern manufacturing industry, green manufacturing is one of the essential solutions of the manufacturing environment pollution problems. Green cutting technology is the base and key of green manufacturing and will be the inevitable trend of cutting technology. High speed machining technology is a kind of the advanced manufacturing technologies which have superiorities as low cost, high efficiency, good processing quality and are suitable for machining thin walled workpieces and difficult-to-cut materials, and the relative problem has attracted scholars' attention from all over the world. From the perspective of green manufacturing, research results of high speed machining hardened steels are reviewed, including cutting force, cutting temperature, selection and optimization of processing parameters and machining quality, and conclude that high speed cutting is one of the key technologies in implementing green manufacturing and cleaner production. Finally, its future works of the research are discussed.


TAPPI Journal ◽  
2014 ◽  
Vol 13 (2) ◽  
pp. 17-25
Author(s):  
JUNMING SHU ◽  
ARTHAS YANG ◽  
PEKKA SALMINEN ◽  
HENRI VAITTINEN

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.


Author(s):  
Emerson da Trindade Marcelino ◽  
Júlio Mannuel Tavares Diniz ◽  
ALVARO ROCHA ◽  
Eisenhawer de Moura Fernandes ◽  
Raimundo Duarte ◽  
...  

2007 ◽  
Author(s):  
R. E. Crosbie ◽  
J. J. Zenor ◽  
R. Bednar ◽  
D. Word ◽  
N. G. Hingorani

2016 ◽  
Vol 30 (06) ◽  
pp. 1650063 ◽  
Author(s):  
Jingwen Sun ◽  
Jian Sun ◽  
Yunji Yi ◽  
Lucheng Qv ◽  
Shiqi Sun ◽  
...  

A low-cost and high-speed electro-optic (EO) switch using the guest–host EO material Disperse Red 1/Polymethyl Methacrylate (DR1/PMMA) was designed and fabricated. The DR1/PMMA material presented a low processing cost, an excellent photostability and a large EO coefficient of 13.1 pm/V. To improve the performance of the switch, the in-plane buried electrode structure was introduced in the polymer Mach–Zehnder waveguide to improve the poling and modulating efficiency. The characteristic parameters of the waveguide and the electrodes were carefully designed and the fabrication process was strictly controlled. Under 1550 nm, the insertion loss of the device was 12.7 dB. The measured switching rise time and fall time of the switch were 50.00 ns and 54.29 ns, respectively.


Lubricants ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 18
Author(s):  
Eckhard Schüler ◽  
Olaf Berner

In high speed, high load fluid-film bearings, the laminar-turbulent flow transition can lead to a considerable reduction of the maximum bearing temperatures, due to a homogenization of the fluid-film temperature in radial direction. Since this phenomenon only occurs significantly in large bearings or at very high sliding speeds, means to achieve the effect at lower speeds have been investigated in the past. This paper shows an experimental investigation of this effect and how it can be used for smaller bearings by optimized eddy grooves, machined into the bearing surface. The investigations were carried out on a Miba journal bearing test rig with Ø120 mm shaft diameter at speeds between 50 m/s–110 m/s and at specific bearing loads up to 4.0 MPa. To investigate the potential of this technology, additional temperature probes were installed at the crucial position directly in the sliding surface of an up-to-date tilting pad journal bearing. The results show that the achieved surface temperature reduction with the optimized eddy grooves is significant and represents a considerable enhancement of bearing load capacity. This increase in performance opens new options for the design of bearings and related turbomachinery applications.


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