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1.
PTCR阻值的控制与调整   总被引:4,自引:0,他引:4  
从晶粒电晶、晶界电阻以及陶瓷基体与金属电极接触电阻三方面详细讨论了材料配方及工艺对PTCR阻值的影响规律,烧结后样品阻值可通过后续处理调整到所需的数值。  相似文献   

2.
介绍了PTCR恢复时间测试的原理、仪器的电路设计和基本性能。仪器综合采用了电阻─电压变换、数字计时和数字显示等技术,测试结果准确、可靠。  相似文献   

3.
宿元斌 《传感器世界》1999,5(5):17-17,20
本文提出了一种新型的钛酸钡热热电阻器的制造方法。研究了它的导电机理,给出了组分,工艺条件及主要参数,提出了改进性能的途径。  相似文献   

4.
从晶粒电阻、晶界电阻以及峋瓷墓体与金属电机接触电阻三方面详细讨论了材料配方及工艺对?% & ? 阻值的影响规律)烧结后样品阻值可通过后续处理调整到所需的数值)  相似文献   

5.
针对冰箱马达启动器用PTCR工作时独特的电流 -时间特性 ,选用 80 98准 16位单片机为核心 ,组成测试系统 ,对系统的软硬件进行了分析。该测试系统能准确检测冰箱马达启动器用PTCR的常温电阻、动作时间、恢复时间和耗散功率。  相似文献   

6.
本文对%& ? ? 一二一, + ? 二) ? , ,. /0 。系半导体陶瓷掺杂) ? , + ? , 1 ?,2 3 衬其性能的影响进行了研究, 获得了合理控制掺杂和烧结的工艺4  相似文献   

7.
PTC元件开关特性建模与测试方法研究   总被引:1,自引:0,他引:1  
由于PTC元件具有良好的开关特性,PTC元件已被大量用于过流保护,彩电消磁以及电机启动等工业领域,为了确保产品的质量,必须对PTC元件的开关特性进行和评估,本文首先通过理论分析,建立PTC元件开关特性的微分方程模型,利用数值方法进行求解,实现了PTC开关特性的仿真,然后以理论分析为基础,构造了两种对开关特性参数-动作时间进行测量的方法,(1)硬件信号调节方法,以AC-DC转换电路为基础,(2)软件信号处理方法,以希尔伯特变换为基础,理论分析及袂验验证表 明,这两种方法的均能有效地测量PTC元件的动物时间参数,其中第(2)种方法的测量精度较高,但同时测试费用也较高。  相似文献   

8.
通过对Si热敏电阻的R-T特性的测试和分析,得到了R-T特性与元件结构之间的一些有益的关系。  相似文献   

9.
本文对(Ba1-x-yPbxCay)TiO3系半导体陶瓷掺杂Ca,Pb,Nb,Mn对其性能的影响进行了研究,获得了合理控制掺杂和烧结的工艺。  相似文献   

10.
问:我使用的是地质出版社的《电子控制技术》,在使用学习P19页第二自然段温度传感器一内容时其中对热敏电阻是这样描述的:·····它具有温度上升、电阻变小的负温度特性或温度上升、电阻变大的正温度特性。请问同一支热敏电阻能有双重特性吗?  相似文献   

11.
Impurities have great influence on the PTCR effect in BaTiO3 ceramics, especially a donor and an acceptor. When Cd replaces Ba as equivalent impurity, neither donor nor acceptor does it act as. However, it was found that doping with either solid CdO or vapor one resulted in the enhancement of the PTCR effect of BaTiO3-based semiconducting ceramics. The mechanism of the enhancement of the PTCR effect is also discussed.  相似文献   

12.
Nb2O5-doped (1 − x)Ba0.96Ca0.04TiO3-xBiYO3 (where x = 0.01, 0.02, 0.03 and 0.04) lead-free PTC thermistor ceramics were prepared by a conventional solid state reaction method. X-ray diffraction, scanning electron microscope, Agilent E4980A and resistivity-temperature measurement instrument, were used to characteristic the lattice distortion, microstructure, temperature dependence of permittivity and resitivity-temperature dependence. It was revealed that the tetragonality c/a of the perovskite lattice, the microstructure and the Curie temperature changed with the BiYO3 content. In order to decrease the room temperature resistivity, the effect of Nb2O5 on the room temperature resistivity was also studied, and its optimal doping content was finally chosen as 0.2 mol%. The 0.97Ba0.96Ca0.04TiO3-0.03BiYO3-0.002Nb2O5 thermistor ceramic exhibited a low ρRT of 3.98 × 103 Ω cm, a typical PTCR effect of ρmax/ρmin > 103 and a Tc of 153 °C.  相似文献   

13.
应用多媒体技术(Multimedia Techmology)制作的计算机辅助教学(MCAI)代表了教育领域中计算机应用技术的发展方向,是教育信息化的重要手段。3DS MAX是制作三维动画的著名软件之一。本文以机械液压调节系统为例,介绍采用3DS MAX制作其工作过程的动画.该动画已经用在《汽轮机原理》MCAI(多媒体教学软件)中,具有形象生动等特点,课堂使用效果很好。  相似文献   

14.
In this paper, we used 3D modeling and nonlinear methods (fractal, multifractal, and probabilistic neural networks (PNN)) for regional mineral potential mapping and quantitative assessment for porphyry and skarn-type Mo deposits and hydrothermal vein-type Pb-Zn-Ag deposits in the Luanchuan region, China. A 3D geological model was constructed from various geological maps, cross sections, boreholes, and gravity and magnetic data. Geological features associated with mineralization were extracted using the 3D geological model and metallogenic models of porphyry and skarn-type Mo and Pb-Zn-Ag deposits. The multifractal method, principal component analysis, and power spectrum-area method were used to separate regional variability from local variability in the geochemical data. A 2.5D forward modeling of gravity and magnetic data was carried out to define the geometry, depth, and physical properties of geological bodies at depth. 3D visualization of the results assisted in understanding the spatial relations between the deposits and the other geological bodies (e.g., igneous intrusions). The PNN method was applied to represent and integrate multiple anomalies for mineral potential modeling. The concentration-area fractal method was used to classify the PNN mineral potential model. Three levels (ground surface and two subsurface horizontal planes) of mineral potential models were evaluated for undiscovered Mo and Pb-Zn-Ag deposits. Validation of the results shows that 3D modeling was useful for not only accurately extracting geological features but also for predicting potential mineral targets and evaluating mineral resources. The mineral potential targets identified consist of eight Mo potential targets and 15 Pb-Zn-Ag potential targets. Based on grade-tonnage data from the known Mo and Pb-Zn-Ag deposits and the results of 3D modeling, estimated potential resources of each of these types of deposits are 10.8 and 153.1 Mt (Pb+Zn is 152.9 Mt and Ag is 0.92 Mt), respectively.  相似文献   

15.
针对目前自动化立体仓库监控技术存在的缺点,提出了一种基于物联网RFID电子标签无线通信技术的自动化立体仓库监控管理系统.系统以物联网技术为核心,通过电子标签实现系统数据的实时采集;同时,利用GPRS无线模块把采集到的数据发送给监控中心,监控中心接收并处理数据,最后将结果显示给用户或发出监控命令,实现系统管理智能化、网络化和信息化.该物联网技术在自动化立体仓库领域具有较好的应用前景.  相似文献   

16.
该设计利用美国ISD公司的系列芯片,采用EEPROM存储方法将模拟语音数据直接写八半导体存储单元,并通过单片机控制,最终完成了语音的再生。同时,对OCMJ液晶模块与单片机的双线握手协议进行了研究。最终,笔者将以上技术在C^3I系统终端单体上应用,实现了高炮射击诸元的自动报读、LCD显示、作战命令语音的存储与下达等功能,最终达到减轻作战人员的视觉负担,缩短高炮射击反应时间的作用。  相似文献   

17.
The divergence of horizontal radiation in vegetation canopies is generally considered to be of negligible consequence to 1) algorithms designed for the physically-based interpretation of space borne observations, and 2) field campaigns aiming at the validation of derived surface products, like FAPAR and albedo. However, non-zero horizontal radiation balances are likely to occur if the internal variability of the vegetation target and the typical distances that photons may travel horizontally within such 3-D media extend to spatial scales that are similar to or larger than those of the measuring sensor. Detailed radiative transfer simulations in 3-D coniferous forest environments are presented to show how the magnitude of local net horizontal fluxes (for spatial resolutions ranging from 1 × 1 m2 to 500 × 500 m2 forest areas) can reach multiple times the incident solar radiation at the top-of-canopy level. Furthermore, the PDFs of these local net horizontal fluxes (H) are skewed toward negative values (meaning that most local canopy volumes have more radiation exiting than entering via their lateral sides), in particular when the radiative regime is dominated by single-scattering interactions and geometric shading is prominent. In order to maintain the energy balance of the overall forest domain, however, local canopy volumes with rather large positive net horizontal fluxes must also exist, thus underscoring the importance of properly locating local flux measurement equipment. Irrespective of the sign of H, it is shown that the local canopy absorption (A) falls within the A = H (perfect shadowing of the forest floor) and A = H + 1 (perfect illumination of the forest floor) domain in the red spectral band. This correlation between A and H implies that the range of local canopy absorption values is far larger than unity which reduces its potential to serve as a proxy in delivering accurate domain-averaged absorption estimates on the basis of spatially incomplete sampling schemes. Instead, it is shown that, for a spatial sampling of 1% of the forest area of interest, local absorption estimates - derived from vertical fluxes only - are sufficient for delivering domain-averaged canopy estimates that lie, on average, within 0.05 of the truth. For forest domains that are smaller than about 30 × 30 m2, however, horizontal radiation transport will still affect the domain-averaged canopy absorption values and thus a spatially exhaustive sampling of the true local absorption may be more appropriate.  相似文献   

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