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②常见多层贴片压敏电阻器外形如图6所示。图6常见多层贴片压敏电阻器外形图图7多层贴片压敏电阻器型号命名规则图在工程技术中,多层贴片压敏电阻器主要作用是:代替瞬态抑制二极管、齐纳二极管和电容器组合,实现稳压、过压保护、灭弧、消噪、补偿、消磁等功能。 相似文献
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一、晶体管压敏保护电路普通电阻器遵从欧姆定律,而压敏电阻器则不然,其伏安特性呈特殊的非线性关系。图1(a)为MY31型氧化锌压敏电阻器结构图。它有一个庞大的家族,它可用于几伏到几万伏的电子线路和交/直流电压线路中,吸收大气过电压和操作过电压,用来保护电器设备或半导体元器件。 相似文献
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本文综述了电涌保护器(SPD)中Zn O压敏电阻器的并联性能和并联实验结果,借用文献[1]的研究成果,利用压敏电压U1m A这一参数进行选片,综合提出了有效的选片方法。在低压电气系统中安装两个或两个以上SPD,综述介绍了SPD之间的能量配合。 相似文献
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一、概述METROSIL是一种以碳化硅为基材的陶瓷半导体材料,其电阻与外施电压有关。因此,由METROSIL制成的电阻器称为压敏电阻器或非线性电阻器。METROSIL压敏电阻器均由碳化硅和陶瓷粘结剂混合制成,用模具压成所需的形状,通常为圆盘形。然后在高温下烧结,烧结时严格控制工艺条件。烧结后圆盘表面喷涂一层金属,以便获得良好的电接触。压敏电阻器的连接既可以采用夹紧圆盘的金属板,也可以(对尺寸较小的成品)将导线用锡直接焊在金属喷涂表面上。 相似文献
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电性能测试结果表明环氧粉末绝缘的ZnO压敏电阻器在湿热环境中放置一段时间后,电性能发生劣化,表现为漏电流增大,非线性指数减小,受湿热作用后,水分道德进入环氧绝缘层,造成介电常数εr和介质损耗因数Ttanδ增大;然后水分在湿热作用下通过环氧绝缘层到达瓷达/绝缘层表面,最终导致压敏电阻器的电性能发生变化。因此,环氧绝缘层吸水 稼水性是造成压敏电阻器湿热劣主要原因。 相似文献
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压敏电阻器在YB—2保安排中的应用扬州电力通讯器件厂郑天良一、概述压敏电阻用于配线架上作为保安器件,替代多年来常规使用的陶瓷气体放电管,是近几年来的事。电力部调通局(1992)45号文件《电力系统通信站防雷整改技术研讨会议纪要》中述及“……氧化锌压敏... 相似文献
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Electrical parameter statistic analysis and parallel coordination of ZnO varistors in low-voltage protection devices 总被引:1,自引:0,他引:1
Jinliang He Shuiming Chen Rong Zeng Xidong Liang Zhicheng Guan Se-Won Han Han-Goo Cho 《Power Delivery, IEEE Transactions on》2005,20(1):131-137
Analyzing the nonuniformity of electrical parameters of ZnO varistors is useful to select and coordinate the ZnO varistors in parallel operation and improve the protection capability of surge-protection device (SPD). The nonuniformity of 1-mA dc voltage and impulse residual voltage of commercial low-voltage ZnO varistors were estimated by statistic analysis in this paper. The Minimum Gobble Distribution was used to describe the distribution of 1-mA dc voltage and impulse residual voltage, ZnO varistors were verified conforming to the Minimum Gobble Distribution by the Kolmogorov-Smirnov test. The relationship between the impulse residual voltage and 1-mA dc voltage has a chaos phenomenon, and they have a close relative degree by t-test, the impulse residual voltage can be estimated by voltage ratio and 1-mA dc voltage. The nonuniform phenomena of electrical parameters of ZnO varistors were simulated by Voronoi network. The current overload of ZnO varistor with reduced residual voltage is serious, in order to keep safe operation of SPDs, when we design a SPD with ZnO varistors in parallel, a safe margin coefficient of discharge withstand current should be considered according to the actual relative standard deviation of surge residual voltages of used ZnO varistors. 相似文献
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本文就氧化锌压敏电阻器的工频过电压特性(以下称TOV特性)的重要性、正确表征和影响因素展开讨论。提出TOV特性应以TOV幅值及对应的耐受时间来表述,称为TOV耐受时间特性,作为给SPD应用的氧化锌压敏电阻器的设计应用资料,则应提供两个数据,一是TOV耐受时间特性,二是暂态过电压施加时温度随时间变化数据。氧化锌压敏电阻器的TOV耐受时间特性,直接与耐受TOV能量的能力以及TOV工作区(1mA~10A)V-I特性曲线相关,制约耐受TOV能量的能力的因素,是配方与工艺引起的晶相差异和结构的均匀性,以及热稳定性。TOV工作区(1mA~10A)V-I特性曲线,除了受配方与工艺影响外,还受工作历史的影响。电阻体均匀性好的TOV特性好,而TOV工作区(1mA~10A)V-I特性曲线非线性差或电压正温度数引起加载TOV时电流变小,可以提高TOV耐受时间。 相似文献
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Nikitin V. V. Sychugov A. N. Rolle I. A. Vikulov I. P. 《Russian Electrical Engineering》2020,91(2):87-92
Russian Electrical Engineering - A technique to determine the type and number of varistors has been considered that is based on using the maximum long overvoltage applied to varistors on the... 相似文献
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Renaud Metz Celine Machado Mehrdad Hassanzadeh Ramon Puyane 《Journal of Electroceramics》2004,13(1-3):825-827
This work reports on a process (DOPA: Direct Oxidation of a Precursory Alloy) of preparation of ceramics used as varistors for the electric protection against power surges. This new route has been applied for the production of ZnO varistors doped with Bi2O3, Sb2O3 and other oxides. One important stage of this process is the total conversion of an alloy into the corresponding mixed oxide. We have reported here the studies of the full conversions metal-ceramic powders of the main components of these varistors: zinc and bismuth. 相似文献
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An overview is given of zinc oxide varistors, which are made of semiconducting ceramics with highly nonohmic current-voltage characteristics, which originate at the grain boundaries. These varistors are widely utilized to protect electric power lines and electronic components against dangerous voltage surges. This overview covers electrical characteristics, fabrication methods, effects of additives, microstructures, the conduction mechanism, degradation, and applications 相似文献
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局放及潮湿对氧化锌阀片性能的影响及对策 总被引:4,自引:1,他引:3
进行系列试验以研究局放及潮湿对经锌阀片性能的影响,查明未用气密材料包裹的阀片在局放及/或潮湿环境下运行,将发生劣化,研究聘种绝缘配方及工艺,在保持氧化锌阀片原有各项性能基础上,大大提高了氧化锌阀片在局放及潮湿环境下的稳定性。 相似文献
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采用幅值为20 kA、时间间隔为50 ms的同时序冲击高压5脉冲分别对单片氧化锌压敏电阻元件、2片压敏电压相差10 V、2片压敏电压相同的并联压敏电阻进行冲击试验。试验表明单片压敏电阻难以承受多脉冲的大能量,将幅值为40 kA同样的波形施加在2片压敏电阻并联上时,2片压敏电压相同的压敏电阻并联耐受冲击次数是单片情况下的2倍,而压敏电压相差10 V的2片压敏电阻并联的耐受冲击次数甚至比单片少。通过对多脉冲冲击下的压敏电阻片电气参数、温度测试分析以及外观损坏形式分析,认为多脉冲情况下的损坏机理主要以热击穿为主。 相似文献