共查询到20条相似文献,搜索用时 62 毫秒
1.
本系统以单片机sTc89c52为数据处理和控制芯片,采用恒压源给待测电阻提供稳定电压,通过采样待测电阻Rx上的电压值,经放大后送至A/D转换,然后送人Mcu进行数据处理,并将测量结果通过LcDl2864液晶显示。该测试系统能够实现1Ω-l0MQ电阻量程的自动切换、自动筛选,并耳可以对电位器的阻值变化进行扫描测试,并将测试得到的曲线在LCDl2864液晶显示。 相似文献
2.
3.
4.
设计了一种具有自动电阻筛选测试仪,选用低功耗单片机C8051F005、多路开关CD4051、步进电机驱动芯片TA8435、LCDLM9033液晶显示器等器件。利用多路开关实现量程自动切换,测量量程为100Ω、1KΩ、10KΩ、10MΩ四档,测量精度为1%。用户通过键盘输入要求的电阻值和筛选误差值,测量时能在液晶显示器上显示出被测电阻的阻值以及被测电阻是否符合筛选要求,在自动测量时,液晶显示器能显示电位器阻值随旋转角度变化的曲线。所有电路结构简单,所选器件价格便宜,并给出了测试结果。测试结果表明,该电阻测试仪在自动电阻筛选和自动测量等方面具有较好的指标、较高的实用性。 相似文献
5.
随着计算机科学与技术的飞速发展,当前单片机已占据重要的地位。它最适合目前国内的开发应用。本文介绍用 MC8—51系列8031单片机组成的动态电阻测量电路及软件流程。其特点是可简便地对高密度的集成电路的电阻网络的加工进行自动检测,测量范围大、精度高和速度快。用单片机测电阻,首先是将被测的电阻变换成电压,使被测元件量值的大小反映在电压上;其次是应用 A/D 变换技术将模拟量变成数字量;最后通过单片机系统的运算、数据处理求出元件值并自动显示和打印结果。 相似文献
6.
7.
根据GB-1型真空管繁用表的技术指标,它可以测量高达1000兆欧的高电阻,不过当被测电阻高于10兆欧以后,测量误差就有±20%,而且对接近或高于1000兆欧的电阻,读数很困难.这里介绍一种方法,是利用这种表在测量直流电压时具有高内阻的特点,可以方便而准确地测量出高电阻. 测量时,要用一个100~300伏的直流电压源.先用GB-1测出它的电压为U_1,然后通过被测电阻R_x,再测得这个电压为U_2(如图所示).从图中可见,被测电阻R_x和GB-1的内阻相串联,组成一个分压电路, 相似文献
8.
一、电阻式传感器电阻式传感器是利用电阻元件把待测的物理量如力、位移、形变及加速度等量变换成电阻阻值,从而通过对电阻阻值的测量达到测量该物理量的目的。电阻式传感器按其工作原理可分为以下二类: 1.电位计式电阻传感器 2.应变式电阻传感器电位计式传感器工作于电阻阻值变化较大的状态,适宜测量被测对象参数变化较大的场合,由于此类传感器与一般电位计相同,故不再赘述。应变式电阻传感器工作于电阻阻值变化极小的状态,灵敏度较高,以下作专题介绍。 (一) 应变式电阻传感器原理 相似文献
9.
10.
Marián tofka 《电子设计技术》2009,16(2)
无源分流器用于测量流经一个相对小阻值电阻的电流,一般对较大功率设备其满量程压降为60mV,而对电子仪器为200mV.与之类似,电流/电压转换器用于测量流经检测电阻的电流,它一般有更高的压降.但在某些情况下,输入端与地之间的压降必须尽可能低,OV为理想值(与被测电流无关).如果应用需要这种特性.可以采用图1中的电流/电压转换器.此电路中,电阻R,用作一个经典的电流检测电阻,仪表放大器检测其上的被测电流,从而获得压降. 相似文献
11.
Michael Reilly 《半导体技术》2004,29(12)
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system. 相似文献
12.
Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
16.
Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's. 相似文献
17.
Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
18.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory. 相似文献
20.
《中国通信》2014,(7)
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks 相似文献