Demultiplexers for Nanoelectronics Constructed From Nonlinear Tunneling Resistors

When using linear resistors to implement nanoelectronic resistor-logic demultiplexers, codes can be used to improve the voltage margins of these circuits. However, the resistors which have been fabricated in nanoscale crossbars are observed to be nonlinear in their current versus voltage (I-V) characteristics, showing an exponential dependence of current on voltage; we call these devices tunneling resistors. The introduction of nonlinearity can either improve or degrade the voltage margin of a demultiplexer circuit, depending on the particular code used. Therefore, the criterion for choosing codes must be redefined for demultiplexer circuits built from this type of nonlinear resistor. We show that for well-chosen codes, the nonlinearity of the resistors can be advantageous, producing a better voltage margin than can be achieved with linear resistors     

Digitally programmable active-R square wave generator

A digitally programmable active-R square-wave generator circuit is discussed. The circuit uses only two operational amplifiers, two operational transconductance amplifiers, and resistors. The main features of the circuit are the following: it uses only resistors without recourse to any external capacitors. Therefore, it is attractive for monolithic implementation. It can be used with any mini/microcomputer or microprocessor-based system. It is possible to obtain a linear relationship between the control voltage and the frequency of oscillation. Experimental results are presented     

The Accuracy of Series and Parallel Connections of Four-Terminal Resistors

The range and accuracy of resistance calibration can be increased by the use of series and parallel connections of four-terminal resistors. Low value resistors can be permanently connected in series and reconnected in parallel by using Hamon's1 technique to change resistance level without materially affecting resistance accuracy. The resistors are connected in parallel by attaching shorting bars to one terminal at each end of each resistor and attaching matched resistors in series with the other terminals. High accuracy can be attained even though lead and connection resistance are relatively high. The purpose of this paper is to provide a theoretical base and an error analysis to justify the use of the series-to-parallel transfer technique at low resistance levels. The analysis uses a four-terminal equivalent circuit suggested by Searle.2 The accuracy of series and parallel connections of groups of like resistors is investigated in terms of the equivalent circuit. Procedures are developed for determining the connection accuracy of a set of resistors in parallel or series.     

在线电阻测量仪电路

本文提出了一种在线电阻测量电路。这种电路具有等电位隔离特性,能消除电网络中其它电阻对被测电阻的影响,可实现网络电阻的直接测量。文中对误差进行了分析,给出了实验结果。     

Compensation for temperature effects in the emf of potentiometer standard cells

Conclusions The above compensation circuit with copper or nickel resistors can be used both in manually operated and automatic potentiometers. The temperature-sensitive resistors should be placed close to the standard cell so that they should all be at the same temperature.     

Effect of Conductance Variability on Resistor-Logic Demultiplexers for Nanoelectronics

On a mixed-scale nanoelectronic crossbar, in which nanowires cross CMOS-scale wires at right angles, a demultiplexer circuit may be laid out using configurable resistors at the crosspoint junctions. This circuit can function as an interface between conventional CMOS microelectronic circuitry and the smaller nanocircuitry by allowing a few CMOS address lines to control a much larger number of nanowires. The voltage margin properties of these resistor-demultiplexers can be improved by basing them on error-correcting codes. In any real fabrication process, the conductances of the resistors in the demultiplexer circuit will be distributed over a range of values. Using simulation, we investigate how variability in the conductances affects the voltages on the output lines of the demultiplexer, and the related voltage margin of the overall circuit. The simulation results provide a simple quantitative relationship revealing that the voltage variability is smaller than the component variability.     

Calculable coaxial resistors for precision measurements

Coaxial straight-wire resistors have been constructed with the purpose of improving comparisons between resistors, capacitors, and inductors in the audio-frequency range. The design is based on the principle that a coaxial line with a cylindrical shield can be described by relatively simple equations for the real and imaginary parts of the impedance. The resistors, with values at and above 100 Ω will be used as transfer standards for characterization of the frequency dependence of standard resistors and of the quantum Hall resistance in the audio frequency range     

Fabrication of a fully integrated passive module for filter application using MCM-D compatible processes

Integral passive is an emerging technology which is currently perceived as a possible alternative to the discrete passive technology in fulfilling the next generation packaging needs. Although discrete surface mount passive components (resistors, capacitors, and inductors) have been well characterized, the development of integral passive components suitable for co-integration on the board level is relatively recent. Since in some applications the number of passive components can exceed the number and the area of IC chips on a circuit board or in a package, such integration of passive components would be necessary to substantially eliminate part count and reduce device area. To address these issues, integration technology for passive elements in the same manner as for transistors is necessary. In addition, the fabrication sequence of all integral passive components should be mutually compatible for co-integration on the same substrate. In this paper, materials and fabrication issues for passive elements such as resistors (R), capacitors (C), and inductors (L) and the feasibility of integration of these fabricated passive components on glass substrates have been addressed. An active filter circuit has been selected for a case study for R, L, and C co-integration. This passive module contains eleven resistors, four capacitors, and four inductors, and is fabricated using MCM-D (multichip module-deposited) compatible processes. A variety of materials appropriate for fabrication of integral passives in a mutually compatible fashion were investigated, including chromium and nickel-chromium resistors, composites of high dielectric constant materials in epoxies for capacitor dielectrics, and composites of magnetic ferrite particles in polyimides for inductor core and shielding. The fabricated devices showed good agreement between the design values and the corresponding measured values. It is anticipated that some of these materials and fabrication processes can be implemented for the MCM-L (multichip module-laminate) compatible packaging. © 2000 Kluwer Academic Publishers     

A New Resistance-to-Frequency Converter for Temperature Measurements in Calorimeters

A circuit is described for the measurement of the temperature difference between input and output heat exchangers by means of resistance thermometers. Two thermometer resistors form part of a resistance-to-frequency converter, the frequency being proportional to their difference in resistance value. The frequency is also dependent on a few additional resistors and a capacitor. Drifts and offsets of amplifiers are eliminated to a first order. No stabilized voltages are used. The circuit was developed as part of a simple and reliable calorimeter for domestic uses.     

10-kV High-Accuracy DC Voltage Divider

A high-accuracy voltage divider based on the Hamon/Rayleigh ratio principle has been made for the absolute measurement of the volt and also for building up the voltage scale to 10 kV. It is composed of 100 equal resistors of nominal value 100 k? and an adjustable 100-k? resistor with taps at 10 and 1 k?. By using appropriate connections, a total 10-M? divider with 1-k? output is constituted in which various voltage ratios up to 104 can be obtained. A guard circuit is provided to minimize the leakage currents. The calibration of the divider is simplified by using parallel or series-parallel connection of resistance elements so that all comparisons are made at a ratio of 1:1. For 10 kV only, two comparisons are required. The measurement of performance of the divider and the analysis of errors have been made. The most important factor affecting the voltage ratio is self heating, for which a correction is necessary. The total error would be less than 0.58 ppm.     

基于机器视觉的贴片电阻封装排序方法

目的研究基于机器视觉的贴片电阻封装排序方法,确保贴片电阻的封装效率,减少人力成本。方法基于模板匹配设计一种贴片电阻的相对方向识别方法,并简单介绍检测系统的整体框架。识别方法主要分为3步,截取模板并进行模板匹配;记录匹配区域的匹配度及匹配区域的像素坐标信息;利用匹配度和坐标信息得出贴片电阻的相对方向。结果文中验证了在不同光源下的识别率。当光源强度为18 V时,识别率最高,达到99.9%,处理时间约为130 ms。结论基于机器视觉的贴片电阻封装排序方法能够满足工业生产的准确性和实时性要求。     

货物大小自动分类包装机的设计

目的针对目前网络销售货物存在的包装效率低下、人工成本高等问题,设计一台可实现对不同尺寸货物进行自动分类的包装机。方法通过距离光电传感器检测货物的大小,将尺寸不同的货物进行分类,用机械手臂拾取分类好的货物,并放到传送带运送的盒子内,再利用气缸的运动将货物进行封装,最后利用自动打包机将封装好的货物进行外部包装。结果所设计的货物分类包装机能实现对货物进行快速分类、包装,采用气缸带动机器运动,实现了自动化控制,不需人为操作,结构更简单,操作更方便。结论货物自动分类包装机可以用于多种尺寸商品的分类、包装,既可以帮助大型商店、物流公司整理繁杂的货物,又可以帮助小型网店快速整理、包装多品种货物,提高了效率,减少了人工资源浪费。     

JFET Circuit Linearizes Transducer Output

A circuit employing one operational amplifier, one dualjunction field-effect transistor, four resistors, and two potentiometers is used to produce a voltage output proportional to the quantity t when the input voltage is related to t by at + bt2, where a and b are constants. The useful operating voltage range, the maximum value of bt/a that can be accommodated, the accuracy of the linearizing process, and the effects of changes in the ambient temperature on the circuit are considered.     

基于体积扫描容重法的社区垃圾分类系统研究

目的 响应国家垃圾分类政策，通过设计社区生活垃圾分类设备检测系统，提高分类正确率，改善“混投乱投”的现状，从源头提高城市垃圾分类投递的准确性。方法 结合现有针对垃圾容重区间划分方法和多种评价标准，总结归纳各类垃圾的容重阈值划分区间，并将其作为垃圾分类的判断方法。设计体积检测模块，利用激光测距传感器点阵获得待测物切片遮挡图和截面积，并计算待测物体积，结合称重传感器计算待测物容重，并依据容重区间对待测物进行分类判断。结果 根据容重阈值分类标准，对多种随机样本进行检测。绝大多数可回收物和厨余垃圾的容重检测值在各分类的容重阈值内，可以被正确分类；其余样本在混合垃圾容重阈值内，符合边界条件设定和模糊垃圾的样本按其他垃圾标准处理的分选原则，检测结果符合分类要求。结论 基于体积扫描检测容重的社区生活垃圾分类系统可以满足居民前端投递环节中对生活垃圾分类检测的需求，有助于提高源头分类的准确性，能有效推进我国垃圾分类和再生资源利用工作的发展。     

基于机器视觉的纽扣电池托盘分拣系统

目的为了提高电池生产企业的检测效率,避免误检,以降低企业生产成本。方法分析传统分拣方式中存在的不足之处,以ABB并联机器人和美国康纳智能相机为平台,搭建一个基于机器视觉的工业机器人分拣系统。运用经典的SIFT算法对分拣对象的图片信息进行处理,克服了光照和位置变化对视觉系统造成的不良影响,提高分拣了效率。结果 ABB并联机器人根据图像信息能识别出待分拣的物体,且工作稳定、可靠,分拣成功率为100%。结论该分拣系统软硬件设计合理,满足了电池生产企业的要求。     

Thermometry using 18 W carbon resistors in a temperature region around 10 mK

The resistance-temperature characteristics of $\text{1}\text{8}$ W carbon resistors of grade ERC-18SG, manufactured by Matsushita, with the nominal values of 48, 82, 100, 220, and 330 Ω have been measured in the region 4.2 K-25 mK and their application as thermometers in this region is confirmed. For the 82 Ω resistor, measurements were taken at temperatures below 10 mK. The temperature dependence of the resistance was found to be linear on the log-log plot over a wide range below 50 mK. The sensitivity remains finite even at 6 mK, but below 10 mK rapid measurements were prevented by a considerable increase in the thermal relaxation time. Measurement of the characteristics of several 100 Ω resistors from two different sets showed that resistors from the same set separate into two groups with different characteristics. This becomes appreciable at temperatures below 4.2 K, so it is difficult to predict the behaviour of Matsushita resistors below 4.2 K from the characteristics at higher temperatures.     

Constant-time parallel sorting algorithm and its optical implementation using smart pixels

Sorting is a fundamental operation that has important implications in a vast number of areas. For instance, sorting is heavily utilized in applications such as database machines, in which hashing techniques are used to accelerate data-processing algorithms. It is also the basis for interprocessor message routing and has strong implications in video telecommunications. However, high-speed electronic sorting networks are difficult to implement with VLSI technology because of the dense, global connectivity required. Optics eliminates this bottleneck by offering global interconnects, massive parallelism, and noninterfering communications. We present a parallel sorting algorithm and its efficient optical implementation. The algorithm sorts n data elements in few steps, independent of the number of elements to be sorted. Thus it is a constant-time sorting algorithm [i.e., O(1) time]. We also estimate the system's performance to show that the proposed sorting algorithm can provide at least 2 orders of magnitude improvement in execution time over conventional electronic algorithms.     

电流模精密整流电路

由电压型运算放大器组成的精密整流电路要严格地匹配电阻才能获得精密全波整流波形．本文给出一种具有CCⅡ电路特性由运算放大器AD844所构成的电流模精密整流电路．无需匹配电阻就可输出良好的精密全波整流波形．且具有输入电压范围大，频带宽等特点．     

Engineering Supramolecular Polymer Conformation for Efficient Carbon Nanotube Sorting

Supramolecular polymer sorting is a promising approach to separating single‐walled carbon nanotubes (CNTs) by electronic type. Unlike conjugated polymers, they can be easily removed from the CNTs after sorting by breaking the supramolecular bonds, allowing for isolation of electronically pristine CNTs as well as facile recycling of the sorting polymer. However, little is understood about how supramolecular polymer properties affect CNT sorting. Herein, chain stoppers are used to engineer the conformation of a supramolecular sorting polymer, thereby elucidating the relationship between sorting efficacy and polymer conformation. Through NMR and UV–vis spectroscopy, small‐angle X‐ray scattering (SAXS), and thermodynamic modeling, it is shown that this supramolecular polymer exhibits ring–chain equilibrium, and that this equilibrium can be skewed toward chains by the addition of chain stoppers. Furthermore, by controlling the stopper–monomer ratio, the sorting yield can be doubled from 7% to 14% without compromising the semiconducting purity (>99%) or properties of sorted CNTs.     

Active feedback circuit for minimization of voltage transientsduring pulsed measurements of semiconductor devices

The operation of an active feedback circuit that minimizes voltage transients during pulsed-I-V measurements is presented. A field-effect transistor (FET) is used as the nominal device under test (DUT). The feedback circuit detects the sag in drain voltage that is caused by voltage drops produced across both the inductor in the drain bias tee and any series resistance in the drain-current path. The feedback signal consists of the current injected into the drain circuit that is sufficient to minimize the change in drain voltage. The feedback circuit actively synthesizes a small driving-point impedance that is seen by the drain of the DUT and is on the order of 10^-2 Ω. Larger voltages do not need to be applied to the drain circuit in order to overcome the nominal inductive and resistive voltage drops. Therefore, a low-current power supply can be used to set V_ds for low- or high-power FETs. Transient responses with and without the use of the feedback circuit are presented. Pulsed-I-V measurements using this feedback method (made less than 1 μs after the start of the gate pulse) of a high-power FET are also presented