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大屏幕彩电常见场故障检修方法
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作者 房亚民 《家电科技(维修与培训)》 2004年第2期15-16,共2页
在大屏幕彩电的实际维修过程中,场故障是常见故障之一,但因其引起故障原因众多,故障表现形式多种多样,致使不好准确判断故障部位,对初学者更是较为棘手,本文将通过实际维修中总结的实例来阐述其常见故障现象及排除方法。
关键词 大屏幕彩电 场故障 检修方法 T2910N C2919P C74P2M
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基于双目立体视觉的变电站空间毫米级区域故障三维场域监测方法 被引量:2
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作者 李文伟 朱龙 陈子文 《计算技术与自动化》 2023年第4期99-104,共6页
针对变电站三类基础故障复杂度较高、无法定位空间毫米级区域故障、故障分析不全面、检测精度低等问题,提出了基于双目立体视觉的变电站空间毫米级区域故障三维场域监测方法。该方法采用双目立体视觉建立成像模型,对该模型校订后进行变... 针对变电站三类基础故障复杂度较高、无法定位空间毫米级区域故障、故障分析不全面、检测精度低等问题,提出了基于双目立体视觉的变电站空间毫米级区域故障三维场域监测方法。该方法采用双目立体视觉建立成像模型,对该模型校订后进行变电站空间毫米级区域故障三维场域图像的采集与处理,以此消除噪声污染,提升监测效果;依据结果基于改进Hu不变矩提取故障特征向量,让其在正则化极限学习机模型中训练并得出最终结果,从而实现该监测。实验结果表明,通过对该方法开展对比测试,验证该方法的图像质量最高,对六种故障状态的检测准确率均维持在80%以上,最高接近100%。该方法提高了对故障监测的精度,具有较好应用前景。 展开更多
关键词 双目立体视觉 变电站空间毫米级区域 故障三维域监测 图像预处理
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彩电彩显场消隐不良故障的分析与维修
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作者 郑家奎 《泰安师专学报》 2000年第3期82-82,共1页
本文详细介绍了彩电、彩显场扫描不良故障的典型现象、电路故障范围、故障产生的原因及维 修方法。
关键词 彩电 彩显消隐不良故障 维修 电路故障
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牡丹47C10型彩电场不同步疑难故障检修
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作者 韩家民 《电子世界》 2000年第6期37-37,共1页
故障现象 牡丹47C10型彩电收看时,图像和伴音正常,场扫描出现不同步现象,并且在图像整幅向上缓慢移动时,伴随轻微的行扭曲。 分析与检修 该机场扫描小信号处理在CD5435CP内完成,调节场频电位器R407能使图像有短暂的同步点,这说明场振荡... 故障现象 牡丹47C10型彩电收看时,图像和伴音正常,场扫描出现不同步现象,并且在图像整幅向上缓慢移动时,伴随轻微的行扭曲。 分析与检修 该机场扫描小信号处理在CD5435CP内完成,调节场频电位器R407能使图像有短暂的同步点,这说明场振荡、场锯齿波的形成电路基本正常,应在同步分离或它前面的相关电路(见图1)中查找故障的原因。 展开更多
关键词 牡丹47C10型 彩电 不同步故障 检修
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TA8759(TA8659)全制式解码与行场扫描故障检修要领(上)
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作者 张奕武 《家电维修》 1997年第1期7-9,共3页
关键词 彩色电视 扫描故障 维修
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基于免疫机理的设备异常度检测与故障诊断快速融合方法研究 被引量:22
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作者 张宏利 刘吉成 +2 位作者 李栋 杨洪柏 刘树林 《机械设计与制造工程》 2016年第11期96-101,共6页
针对设备异常度检测与故障诊断相分离的问题,首先基于数据势场理论,对设备状态空间的划分方法进行研究,在此基础上详细地研究了设备异常度检测与故障诊断快速融合诊断的机理,提出了应用于设备融合诊断的单故障非己势场检测器。然后以凯... 针对设备异常度检测与故障诊断相分离的问题,首先基于数据势场理论,对设备状态空间的划分方法进行研究,在此基础上详细地研究了设备异常度检测与故障诊断快速融合诊断的机理,提出了应用于设备融合诊断的单故障非己势场检测器。然后以凯斯西储大学轴承标准数据集为例,对所提出的设备快速融合诊断方法的合理性进行了验证。最后通过故障隶属度曲线,证明了所提出的融合方法的有效性。 展开更多
关键词 设备检测 故障诊断 异常度 故障非己势检测器 快速融合诊断
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考虑故障概率的进口箱区场桥保养与调度联合优化
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作者 姚琳 郑红星 刘保利 《大连海事大学学报》 CAS CSCD 北大核心 2024年第2期119-130,共12页
为有效减轻集装箱码头进口箱区中频发的场桥故障的影响,提高堆场提箱作业效率,探讨场桥的保养和调度联合优化问题。在计划期内,考虑场桥作业量对其故障概率的影响,兼顾场桥作业安全间隔及集卡等待时长限制,以作业成本、保养成本和故障... 为有效减轻集装箱码头进口箱区中频发的场桥故障的影响,提高堆场提箱作业效率,探讨场桥的保养和调度联合优化问题。在计划期内,考虑场桥作业量对其故障概率的影响,兼顾场桥作业安全间隔及集卡等待时长限制,以作业成本、保养成本和故障导致的机会成本最小为优化目标构建数学模型。针对模型特点,设计了嵌入大邻域搜索的遗传算法对模型进行求解。通过对大连港某码头进口箱堆场的数值实验,在与不同调度方案对比中,本文提出的调度方案使得平均成本降低了3.35%;在与不同保养策略的对比中,本文提出的保养策略使得平均成本降低了2.84%。通过不同规模的算例对比验证了算法的科学性,可为码头日常运营提供决策支持。 展开更多
关键词 集装箱码头 桥保养 桥调度 故障 启发式算法
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Industrial LAN for Vibration Monitoring and Fault Diagnosis of Turbo-Generator
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作者 卢荣军 高亹 Joseph Mathew 《Journal of Southeast University(English Edition)》 EI CAS 2001年第1期46-49,共4页
The unique of using industrial LAN based on field bus to construct the system of vibration monitoring and fault diagnosis is introduced. The LAN topology, client/server architecture, database and designing of applicat... The unique of using industrial LAN based on field bus to construct the system of vibration monitoring and fault diagnosis is introduced. The LAN topology, client/server architecture, database and designing of application software for vibration monitoring and fault diagnosis are involved. How to apply industrial LAN to the vibration monitoring and fault diagnosis of turbo generator is discussed, and a scheme of how to construct the industrial LAN for vibration monitoring and fault diagnosis of turbo generator is presented. 展开更多
关键词 field bus vibration monitoring fault diagnosis
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同密同步器在天津卫视高清条件接收系统中的作用
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作者 陈立伟 《广播与电视技术》 2015年第11期99-102,共4页
在条件接收系统中同密同步器起着重要的作用,它在系统中用于协调ECMG和CWG的同步协调工作。本文对同密同步器工作的原理和机制进行了研究,同时对天津卫视高清加密系统中出现的黑场故障进行了分析,并针对故障原因对系统进行了完善。
关键词 同密同步器 控制字 授权控制信息 场故障
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Effects of Surface Etch Hole Fault on the Velocity Field in Microchannel Reactors 被引量:2
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作者 尤学一 李胜华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第6期919-924,共6页
Microchannel reactors are commonly used in micro-chemical technology. The performance of microreactors is greatly affected by the velocity field in the microchannel. The flow field is disturbed by the cylindrical etch... Microchannel reactors are commonly used in micro-chemical technology. The performance of microreactors is greatly affected by the velocity field in the microchannel. The flow field is disturbed by the cylindrical etch holes caused by air dust on the microchannel surface during its processing procedure. In this approach, a two-dimensional computational fluid dynamics (CFD) model is put forward to study the effect of etch holes on flow field. The influenced area of single or two concave etch holes is studied for the case of laminar flow. The hole diameter, the Reynolds number and the distance between the center of holes are found to have influences on the flow field. Numerical results indicate that the effects of etch hole on the flow field should be evaluated and the way of choosing the economic class of cleanroom for microreactor manufacture is presented. 展开更多
关键词 MICROCHANNEL processing faults etch holes computational fluid dynamics velocity field
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Influence analysis of local heat source on internal temperature distribution of power transformer 被引量:1
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作者 BAO Yanyan FENG Tingna +3 位作者 ZHANG Guangdong LIU Kang MA Jianqiao ZHOU Xiaodong 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第2期218-225,共8页
Oil immersed power transformer is the main electrical equipment in power system.Its operation reliability has an important impact on the safe operation of power system.In the process of production,installation and ope... Oil immersed power transformer is the main electrical equipment in power system.Its operation reliability has an important impact on the safe operation of power system.In the process of production,installation and operation,its insulation structure may be damaged,resulting in partial discharge and even breakdown inside the transformer.In this paper,S9-M-100/10 oil immersed distribution transformer is taken as the research object,and the distribution laws of electromagnetic field and temperature field in transformer under normal operation,inter turn short circuit and inter layer short circuit are simulated and analyzed.The simulation results show that under normal conditions,the temperatures at the oil gap between the transformer core and the high and low voltage windings and the middle position of the high-voltage winding are high.When there are inter turn and inter layer short circuit faults,the electromagnetic loss of the fault part of the transformer increases,and the temperature rises suddenly.The influence of the two faults on the internal temperature field of the transformer is different,and the influence of the inter turn short circuit fault on the temperature nearby is obvious.The analysis results can provide reference for the thermal fault interpretation and fault classification of transformer. 展开更多
关键词 oil immersed power transformer finite element method electromagnetic field short circuit fault temperature field
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Modern tectonic stress field deeply in Xuzhou Coal Mine 被引量:3
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作者 Zhen-jie JING Fu-ren XIE Xiao-feng CUl Jing-fei ZHANG 《Journal of Coal Science & Engineering(China)》 2013年第1期14-18,共5页
By inverting fault slip data, the parameters of 12 tectonic stress tensors in the mine region can be determined. The following characteristics can be obtained for recent tectonic stress fields, which are found deep in... By inverting fault slip data, the parameters of 12 tectonic stress tensors in the mine region can be determined. The following characteristics can be obtained for recent tectonic stress fields, which are found deep in the study region. The results show that the recent tectonic stress field mainly presents the characteristics of near NWW-SSE maximum compressional stress and near NE-SW minimum extensional stress, while the stress regimes are mainly of strike slip, part of the reverse-fault type. Recent tectonic stress field in the region is characterized by horizontal components. The maximum principal compression stress direction was from NEE to SEE, the average principal compression stress direction was near NWW-SSE maximum compres- sional stress and near NE-SW minimum extensional. The recent tectonic stress field of the studied area can be controlled by a large tectonic stress area. 展开更多
关键词 Xuzhou region fault slip data tectonic stress field INVERSION
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Surface Breakdown of Printed Circuit Board under Magnetic Field with Reduced Pressure
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作者 杜伯学 朱晓辉 +1 位作者 高宇 卢欣 《Transactions of Tianjin University》 EI CAS 2010年第1期6-10,共5页
Epoxy resin laminate onto which a pair of copper foil was printed was employed as test samples.The samples were placed in an artificial atmospheric chamber, which was vacuumed by a rotary pump from 100 kPa to 5 kPa.Th... Epoxy resin laminate onto which a pair of copper foil was printed was employed as test samples.The samples were placed in an artificial atmospheric chamber, which was vacuumed by a rotary pump from 100 kPa to 5 kPa.The magnetic field was produced by permanent magnets that were assembled to make E×B drift away from, into and parallel to the sample surface, respectively.Magnetic flux density was adjusted at 120 mT, 180 mT and 240 mT respectively.By applying a negative bias voltage between the electrodes, the ... 展开更多
关键词 printed circuit board surface breakdown magnetic field ambient pressure
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彩电场回扫线故障的分析与检修
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作者 王永建 《家电检修技术》 1995年第11期11-13,共3页
彩色电视机常常会出现“场回扫线”的故障,其特征为满屏或半屏回扫线,图像极淡或无图像,也有亮度,对比度失控现象,或满屏呈某一单色。故障涉及到亮度信号处理电路(包括ABL电路)、消隐电路、视放电路、显像管电路等,在检修时须仔细观察... 彩色电视机常常会出现“场回扫线”的故障,其特征为满屏或半屏回扫线,图像极淡或无图像,也有亮度,对比度失控现象,或满屏呈某一单色。故障涉及到亮度信号处理电路(包括ABL电路)、消隐电路、视放电路、显像管电路等,在检修时须仔细观察故障现象,并配合调整亮度,对比度和加速极电压,区别故障的不同特征,准确判断故障范围,快速排除故障。下面根据故障的不同特征分别进行分析: 展开更多
关键词 彩色电视 回归故障 维修
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东霸D—2188彩电场线性不良故障检修
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作者 张同俊 《家电检修技术》 2002年第11期12-13,共2页
故障现象:上部图像明显拉长、光栅稀疏,下部光栅密集、图像压缩并反卷重叠倒置。分析与检修:据故障现象分析,显然是场输出电路部分不正常。该机采用的是LA7840集成电路作场输出级,对I^2C总线控制的单片电视信号处理集成电路LA76810形成... 故障现象:上部图像明显拉长、光栅稀疏,下部光栅密集、图像压缩并反卷重叠倒置。分析与检修:据故障现象分析,显然是场输出电路部分不正常。该机采用的是LA7840集成电路作场输出级,对I^2C总线控制的单片电视信号处理集成电路LA76810形成的场锯齿波电压进行功率放大,推动场偏转线圈,具体电路如图1所示。通常场扫描故障大多是由于场输出部分的电解电容变值、失效造成的(如:漏液、漏电等)。此机较新,使用时间不太长,查看各电解电容外形均完好,更换场输出N451(LA7840)集成电路外围的电解电容试机,故障依旧,分别检查低阻值的各个水泥电阻,也无问题。 展开更多
关键词 东霸D-2188 彩电 线性不良故障 检修
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Coordination between Fault-Ride-Through Capability and Over-current Protection of DFIG Generators for Wind Farms
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作者 B. Bak-Jensen T.A. Kawady M.H. Abdel-Rahman 《Journal of Energy and Power Engineering》 2010年第4期20-29,共10页
Fault Ride-Through (FRT) capabilities set up according to the grid codes may affect the performance of related protective elements during fault periods. Therefore, in this paper the coordination between the FRT capa... Fault Ride-Through (FRT) capabilities set up according to the grid codes may affect the performance of related protective elements during fault periods. Therefore, in this paper the coordination between the FRT capability and over-current protection of DFIG Wind Generators in MV networks is investigated. Simulation test cases using MATLAB-Simulink are implemented on a 365-MW wind farm in AL-Zaafarana, Egypt. The simulation results show the influence of the FRT capability on the protective relaying coordination in wind farms, showing that the FRT may work in situations where is were expected not to work, and then disabling the over-current protection, which should have worked in this situation. 展开更多
关键词 Wind farms protection dynamic modeling MATLAB-SIMULINK FUSE DOUBLY-FED induction generators
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Identification of meta-instable stress state based on experimental study of evolution of the temperature field during stick-slip instability on a 5° bending fault 被引量:31
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作者 MA Jin S I SHERMAN GUO YanShuang 《Science China Earth Sciences》 SCIE EI CAS 2012年第6期869-881,共13页
Identification of the meta-instable stress state and study of its mechanism and evolution of relevant physical fields would be of great significance for determination of potential seismic risks and estimation of criti... Identification of the meta-instable stress state and study of its mechanism and evolution of relevant physical fields would be of great significance for determination of potential seismic risks and estimation of critical times. In laboratory experiments, that the specimen enters the meta-instable is marked by accelerated stress release. Could we use the experimental result to identify the earthquake in natural conditions? Because the observational data from one station can only reflect the stress state beneath this station, the key problem for identification of the meta-instability is how to recognize regional stress state through observational data from many stations. In this work, we choose the evolution of the temperature field over varied deformation stages during a stick-slip event on a 5 bending fault as an example, and attempt to find the response features of the physical quantity when the fault enters the meta-instable state. We discuss the characteristics of stages for the stress build-up, stress-time process deviating from linearity before instability, meta-instability, instability, and post-instability, respectively. The result shows that the fault instability slide is a conversion process from independent activities of each fault segment to synergism activity. The instability implies completion of the synergism. The stage deviating from linearity is the onset of stress release, and it is also the onset of the synergism. At the meta-instability stages, stress release becomes dominant, while the synergism tends to finish. Therefore, the analysis of the regional overall stress state should not start from individual stations, and instead it should begin with the evolution of the whole deformation field. 展开更多
关键词 earthquake risk stress state meta-instable state evolution of the temperature field synergism bending fault
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加速极电压还是不提为好
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作者 孙国元 《家电检修技术》 2003年第1期23-23,共1页
拜读了詹新生先生2002年9期《“黑屏”故障的维修技巧——提高加速极电压》一文后,本人有点不同意见提出来与詹先生商榷。笔者以为:区分“黑屏”保护,还是亮度通道故障有两种简单的方法:(1)对那些有“黑屏”保护功能且没有维修开关的彩... 拜读了詹新生先生2002年9期《“黑屏”故障的维修技巧——提高加速极电压》一文后,本人有点不同意见提出来与詹先生商榷。笔者以为:区分“黑屏”保护,还是亮度通道故障有两种简单的方法:(1)对那些有“黑屏”保护功能且没有维修开关的彩电,将维修开关拨到维修状态,“黑屏”保护会自动解除。这时如出现一条水平亮线。 展开更多
关键词 加速极电压 维修 彩电 扫描故障
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