Low-Power Analog-to-Digital Converter and Multiplexer

A serial analog-to-digital converter is described, with a resolution of 9 b at a word rate of 5 kHz for input voltages of ±0.5 V, at a total power dissipation of approximately 10 mW. A 10-channel multiplexer is included. Although designed originally for application in implantable telemetry systems, this design should prove useful for other low-power data acquisition requirements.     

Dynamic Model of Analog-to-Digital Tracking Converter

A mathematical model of an analog-to-digital tracking converter is described. By means of the model it is possible to take into account the basic factors that influence the precision of the model. Probabilistic characteristics of the dynamic error are obtained and recommendations for arriving at an estimate of this error are given.     

A Very-High-Speed Analog Buffer with Analog-to-Digital Converter

An analog signal with a bandwidth up to 100 MHz is temporarily stored in a relatively inexpensive analog buffer consisting of an oscilloscope screen image on the target layer of a vidicon tube. From this buffer 255 samples are taken, digitized (seven bits sample), and transferred to a digital computer or averager with a rate of 15 000 samples/s. The fastest fill time of the analog buffer is 50 ns, so the minimum time between consecutive samples of the analog input signal corresponds to 2 ? 10-10 s. A modified apparatus could be used to digitize on paper or film recorded curves, etc.     

Dual-Slope Integrating Analog-to-Digital Converter with Digital Self-Calibration

With dual-slope integrating analog-to-digital (A/D) converters, which are most frequently used for relatively slow speed conversion, any drift in the operational amplifiers is a very critical factor in limiting their performance. A method has been proposed to eliminate the drift problem completely [1]. This short paper describes a similar but different approach to solve the problem. Some of the advantages are: no necessity for manual adjustments, the use of inexpensive amplifiers instead of costly units with no performance degradation for the temperature range limited only by digital circuits. The old method is more adaptable to ratiometric conversion, while the new method is more adaptable to normal dual-slope integrating A/D conversion with a reference voltage of opposite polarity to input signals. As is the case with the basic dual-slope converters, no precision components are required.     

An Integrating Analog-to-Digital Converter for Differential Transducers

An improved dual-slope analog-to-digital converter for measurements made with a pair of resistive or capacitive differential transducers is described. The converter can be contrasted with the conventional method in which the transducers are placed in a bridge, the bridge output is amplified, and the conversion is made. In the new converter the transducers are part of the integrator. As a result, conversion of the signal to a time interval takes place at an earlier stage, eliminating the bridge and the amplifier. The method has the same advantages as the dual-slope method and several additional ones. The fractional change in the transducers is obtained as the ratio of the difference and sum of two time periods. As a result, the converter does not need an accurate voltage reference. In addition, errors due to offset in the integrating amplifier are eliminated.     

New Noncontacting Inductive Analog Proximity and Inductive Linear Displacement Sensors for Industrial Automation

Noncontacting inductive sensors are applicable on a large scale for position detection or travel measurement in industrial applications. Reasons for such broad acceptance in many sectors of industry are noncontact and wear-free sensing of the target (any metal object), reliability and robustness, resistance to fouling, water tightness and compact size. The present work is intended to be a systematic, complete, and consistent presentation of the technological innovations, recent implementations and current trends regarding the analog distance and travel sensing offered by noncontacting inductive sensors for industrial applications. It starts with the fundamentals of inductive sensing and presents the physical basics gained by modern analytic and simulation methods, as well as high-level integrated circuits for inductive sensors. The following sections deal with present-day inductive analog proximity sensors and with the distinctive technological innovation offered by the new inductive linear displacement sensors and with miniaturization results achieved through consistent integration.     

Design of a Robust Analog-to-Digital Converter Based on Complementary SET/CMOS Hybrid Amplifier

As a solution to the high speed, ultralow power, and extremely compact ADC circuit block, a complementary single-electron transistor (SET)/CMOS hybrid amplifier-based analog-to-digital converter (ADC) is proposed. It is implemented with a physics-based SPICE model including nonideal effects in real Si-based SET_s such as the tunnel barrier lowering effect, parasitic MOSFET_s operation, and the phase shift of Coulomb oscillation by the bias of a gate other than a main control gate. Its core scheme is the combination of both the amplification of SET current by MOSFET_s and the suppression of a Coulomb blockade oscillation valley current by the differential amplification. In addition, the transient operation of SET/CMOS hybrid circuit-based ADC_s fully accounting for nonideal effects of real SET_s is successfully demonstrated for the first time. Compared with the previous SET-based ADC_s, our ADC makes features of the immunity to nonideal effects, large voltage swing of the output signal, and high load drivability.     

Noise-Enhanced Measurement of Weak Doublet Spectra with a Fourier-Transform Spectrometer and a 1-Bit Analog-to-Digital Converter

We demonstrate an efficient noise dithering procedure for measuring the power spectrum of a weak spectral doublet with a Fourier-transform spectrometer in which the subthreshold interferogram is measured by a 1-bit analog-to-digital converter without oversampling. In the absence of noise, no information is obtained regarding the doublet spectrum because the modulation term s(x) of its interferogram is below the instrumental detection limit B, i.e., |s(x)| < B, for all path difference x values. Extensive numerical experiments are carried out concerning the recovery of the doublet power spectrum that is represented by s(x) = (s(0)/2)exp(-pi(2)x(2)/beta)[cos(2pif(1)x) + cos(2pif(2)x)], where s(0) is a constant, beta is the linewidth factor, and ?f? = (f(1) + f(2))/2. Different values of ?f?, s(0), and beta are considered to evaluate thoroughly the accuracy of the procedure to determine the unknown values of f(1) and f(2), the spectral linewidth, and the peak values of the spectral profiles. Our experiments show that, even for short observation times, the resonant frequencies of s(x) could be located with high accuracy over a wide range of ?f? and beta values. Signal-to-noise ratios as high as 50 are also gained for the recovered power spectra. The performance of the procedure is also analyzed with respect to another method that recovers the amplitude values of s(x) directly.     

A Converter of the Parameters of Capacitive and Inductive Pickups into a Voltage

A method of constructing converters with strobing is considered. Practical examples are given.     

光闸式光纤位移传感器

本文介绍了一种强度调制型光纤传感器-光闸式光纤位移传感器,推导出其调制函数关系式.通过实验表明,与传统的位移传感器相比,其具有精度高、重复性好、无滞后性等优点.引进了均匀光斑装置后能提高工作区域范围,该善线性度.增加了参考通道后有效地减小了光源波动及光纤抖动等干扰信号的影响,更加有利于其在工程中的实际应用.     

一种新型的转炉炉底车

本文介绍了一种作业效率高、省时省力新型的转炉炉底车，其特点是转盘转动灵活，炉底车上项盘径向任意方向均能平稳倾斜一定角度，以保证炉底圆周所受项力均匀可靠，满足炉底安装要求。     

一种新型的光纤位移传感器

本文介绍了一种新型的透射光斑式光纤位移传感器，与传统的位移传感器相比，它具有体积小、精度高、重复性好、无滞后现象等优点。本文从理论上，推导出该传感装置的调制函数关系式，并通过实验进行了验证，实验结果证明，这种光纤位移传感器精度可达0.5μm，并具有较良好的线性度。     

Time Resolution of an Image Converter Camera in Streak Operation

A method of determining the time resolution of an Image Converter Camera using laser radiation is described. Records indicate that time intervals of the order of 3.1O^-12sec are resolvable.     

两级式高压电源变换器的设计与分析

针对小型化行波管对高压电源的特殊应用要求,提出了两级式Boost-半桥谐振倍压高压变换器结构.高压变换器第二级半桥电路利用变压器漏感和开关管寄生电容进行谐振,实现了主开关管的软开关.通过对前级Boost电路进行设计以及后级半桥电路稳态工作原理分析,给出了系统的控制方案,并对后级半桥变换器的软开关实现条件及其与死区时间的关系进行了讨论与分析.仿真结果和实验波形验证了后级半桥变换器具有良好的软开关特性,验证了理论分析的正确性.实验数据表明两级式高压电源变换器具有较高的效率.     

一种新型差动位移变换器

本通过对三段式差动电感变换器轴向磁场分布的研究,找出了其非线性的根本原因,并针对这个问题提出一种新颖的差动式电感变换器的结构形式。实验测试证明,这种结构的变换器的线性范围较同样长度尺寸的传统三段式变换器宽,且灵敏度高、漂移小,精度能够达到要求,同时其结构和绕线工艺也较传统的三段式位移变换器简单,便于工厂进行大批量的生产。     

Estimate of the Average Power of Signals with Fluctuations in the Phases of the Components of Harmonic Oscillations with Aperture Uncertainty of an Analog-to-Digital Converter

Measurement Techniques - Results are presented from studies of the estimation of the average power of signals with phase fluctuations of the components of harmonic oscillations. These studies take...