The SDS-92/TR-48 Hybrid Computer Sytem in Engineering Education

This paper describes how an SDS-92 digital computer has been connected to a TR-48 analog computer by appropriate interface equipment to permit the high information rate capability of the analog computer and the precision of the digital computer to be combined into a practical hybrid system. The value of the hybrid computer as an educational tool is discussed. Some problems solved on the hybrid computer by students of the hybrid computer course at the Department of Electrical Engineering, University of Iowa, are illustrated.     

Purdue's Junior-Level Control Laboratory with Microprocessors

A microprocessor-based direct digital control system laboratory developed at Purdue University is discussed. The microprocessor controller interfaces directly to an analog computer for simulation control or to control components such as motors, heaters, etc. Available resident processor routines (A/D, D/A, arithmetic, timing, etc.) can be easily configured into a digital control system program allowing strategies to be quickly developed and tested. Al operations are performed directly at the control station via a terminal keyboard, and the system has the potential for stand-alone operation with a graphics output terminal A typical digital control system example-servo position control-has been developed for use in the Junior Control Laboratory. In addition to unlimited possibilities for software strategies, patchable features such as comparators, logic circuitry, timing functions, etc., are available on the front panel, allowing quick, efficient development of a complete digital control system.     

Polynomial Root Determination by an Equivalent Transfer Function Simulation on an Iterative Analog Computer

The methods for determining the roots of polynomials by analog computer techniques are varied, but stability analysis is usually of chief concern. The computer approach used in this paper always produces stable operation, and introduces an equivalent transfer function representation of the polynomial, a linear transformation, and a generalized iterative analog computer program. The accuracy obtainable is not comparable to that of digital programs; however, the procedure is basic to engineering analysis and should not be overlooked from the academic viewpoint.     

用“洪图”实现单片机实验的动态模拟演示

讨论了利用“洪图”多媒体编著系统实现单片机实验的动态模拟演示的方法，给出了单片机实验多媒体教学软件的总体设计框图、实验结果动态模拟演示的程序框图以及实现动态模拟演示的部分程序。结果表明，利用“洪图”开发多媒体应用软件，不仅可以缩短软件的开发周期，还可以使应用软件具有较大的灵活性。     

智能温控在R20新对装机上的应用

介绍了在R20新对装机电气设计时应用智能温控、PLC、触摸屏人机界面等技术,从而有效地控制温控系统的温度波动、改善产品质量以及实现人机对话、触摸式电气操作。     

基于PLC和智能仪表的自动称重二级控制系统

研究了以可编程控制器、微型触摸屏和电子秤组成的自动称重二级控制系统，给出了系统流程结构框图；提出了以PLC和触摸屏作为上位机的应用方法，设计了进行参数设置和监控的触摸屏画面；阐述了PLC与下位机电子称重仪表之间进行信息交换的方式，提供了相应的部分梯形图源程序。实践证明，本系统安装调整方便，可视化功能强，性价比高。     

关于量化和A/D-D/A的讨论

数字、量化、量化效应、模拟、模拟量、A/D转换、D/A转换是计算机控制工程和控制理论上的常见概念.静心推敲,发现有不少流行性的误解.例如：不是“量化”而是截尾或四舍五入,不是“数字量”而是bit量,不是“模拟量”而是物理量等.     

VGA转DVI信号转换器的设计

随着以LCD和其他数字平板显示技术的飞速发展,数字视频接口逐渐地被人们广泛应用。本文选择Intersil公司的ISL98003作为模数转换芯片,采用单片机uPSD3234控制,完成了模拟转数字视频信号转换器的设计。模数转换器内置ADC及PLL电路,将模拟的视频信号转化成数字信号,并针对CRT显示的值进行校正,得到适合LCD象素特性的灰度信号。     

Meeting the analog world challenge. Nyquist-rate analog-to-digitalconverter architectures

To bring digital processing and its benefits to bear on real-world applications, the analog signal of interest must be translated into a format a digital computer can utilize. This is the function of the analog-to-digital converter (ADC). After processing by a digital computer or digital signal processor (DSP), the resulting digital stream of information must be returned to its analog form by a digital-to-analog converter (DAC). The methods by which a digital code is generated within the ADC are diverse. We introduce three popular Nyquist-rate ADC architectures used today: the counter ramp ADC, the successive approximation ADC and the flash ADC     

数字模拟技术分析及微机通道的设计

Ａ／Ｄ和Ｄ／Ａ技术是计算机实时控制系统中的重要组成部分．外界的模拟量（如电压、电流等），只有经过Ａ／Ｄ转换为数字量计算机才能接受，加工、处理；同时，只有经过Ｄ／Ａ转换才能使计算机控制各类伺服系统（如调压、调温等）以达到实时控制之目的．根据实际系统的要求和Ｄ／Ａ、Ａ／Ｄ芯片建立微机通道，在特定接口的基础上用软件支持这种转换的完成，同时，给出了一种用Ａ／Ｄ，Ｄ／Ａ进行正道变换的实用系统．系统的设计方法对建立各自模拟系统的读者有一定的借鉴和启迪作用．     

Microprocessor Laboratory Procedure to Introduce Digital Filtering

This note outlines the experimental procedure for four laboratory sessions which introduce digital filtering. The filters are introduced using a comparison with analog computer equivalents. This approach assists the student and provides digital filter structures with considerable functional advantages. The laboratory equipment includes a 16-bit PACE microprocessor development system with analog input and output ports.     

基于MSComm和队列技术的LabVIEW数据采集系统设计

针对传统LabVIEW数据采集系统中串行通信实时性不高和程序运行效率有待提高的现状,提出了一种基于MSComm和队列技术的LabVIEW数据采集系统设计方案。该方案以DSP作为下位机控制核心,实现了模拟前端的数据采集,采用PC机作为上位机,基于LabVIEW 2012开发环境,设计了上位机应用软件,实现了模拟前端采样数据的处理、存储、显示及统计分析等工作。实践结果表明,该设计方案具有运行稳定可靠,硬件接口简单、易用,软件编程简单,易于维护和扩展等优点。     

The PC/video connection

The personal computer (PC) is an integral part of our life. Television (TV) and PCs have a common origin in electronic technology. With respect to pictures and sound, TVs are an analog technology; PCs are digital. The analog video signal can be converted to digital information for storage in the computer memory or displayed on the computer monitor. An example of advancing technology is the video conferencing industry (remote conferencing). It is becoming an alternative to expensive and time-consuming air travel. The video and audio are transmitted using complex equipment, and expensive and relatively scarce high bandwidth satellite channels. Combined, video and computing can take technology even further, for instance into the operating room. Video can be used with a computer for teleconferencing the surgery. This would be especially beneficial in the area such as laparoscopy. A video used with the computer provides two distinct advantages. The ability to interact with a remote viewer (e.g. teleconferencing an operation), and the improved instructional value. We consider the state-of-the-art technology that video and computing can create and use. To do this, each aspect of each technology is reviewed     

Modal reduced dynamic equivalent model for analog type power systemsimulator

Analog type power system simulators are playing important roles in cases where real time dynamic studies are required. Power system reductions are more important in analyses using an analog type simulator than a digital computer due to facilities limitations. This paper describes a modal reduced dynamic equivalent model which was developed for an analog type power system simulator to provide power system reductions. The model is implemented by using a modal analysis approach based on a digital type synchronous generator model. In simulator tests on a 28-machine power system, the model is judged to be useful for representing subsystems to be reduced in an analog type simulator     

Controllable analog emulator for power system analysis

This paper details the development of a controllable analog emulator for power system analysis. The emulator consists of reconfigurable analog hardware for power system emulation and a digital computer, along with associated software, for configuration, control, calibration and data acquisition. The analog hardware is fully controllable via the software interface. System parameters, initial conditions, integration, faults and contingencies can be created or altered via the software with no changes or manual intervention to the analog hardware. This advance overcomes one of the larger drawbacks of older analog computers, which was the need for manual configuration and calibration. The emulation methodology is presented in this paper as well as power system modeling, both theoretical and in analog hardware. The software interface and control is also presented. To validate the operation of the emulator two examples are shown from a prototype emulator. The first being a steady state power flow solution, the second computes the critical clearing time of a generator fault for transient stability.     

LH系列PLC在直线式拉丝机上的应用

本文介绍了HOLLiAS LM系列PLC在直线式拉丝机上的应用。通过通讯连接上位机与下位机,利用模拟量采集模块和模拟量输出模块对变频器进行控制从而控制电机的转速。本系统实现了机电一体化,精度高,具有很高的可靠性。     

The electroquasistatics of the capacitive touch panel

The capacitive touch panel, a high-resolution position sensor intended for computer displays, must be safe and inexpensive and must sense position accurately in spite of electrical noise, dirt, or direct electrostatic discharge. The implementation discussed uses a quasi-static electric field, applied to a semiconducting coating on the panel surface. A touch draws current from the surface. This current can be used to compute position. If the computation is performed properly, the computed position is independent of touch current and panel coating resistivity. The electroquasistatic basis for position measurement with a capacitive touch panel and a system to implement it are described     

在系统可编程模拟器件(ispPAC)离散性探讨

ispPAC的出现使得模拟电路设计中在信号的调理、信号处理及信号的转换方面可采用图形结构语言实现计算机编程设计，此外软件的仿真功能，更使得对设计结果验证具有直观性和便捷性，大大减化了许多模拟电路设计和检测中费时费力的工作。但是，结果的仿真，是计算机对理想电路特性的模拟，同具体电路的实际情况究竟存在多大差距？由于在厂家提供的资料和相关文献中未见报道，作者就此问题进行了探讨。     

Computer Methods Course for Engineers

With the advent of the computer, engineering education had to be altered to accommodate the use of the computer as an engineering tool. Being aware of this need, the Electronic Engineering Department at Monmouth College, West Long Branch, N. J., has developed and is experimenting with a course which prepares students to use both the analog and the digital computer in engineering analysis. The content, purpose, development and laboratory facilities utilized in this course are described. The principal emphasis in the course is on the use of the computer as a tool in analysis and design.     

Application of Desk-Top Computers as Aids in Teaching Mathematics

Some basic, unpretentious analog circuits are presented which may be useful in demonstrating mathematical concepts introduced at the senior high and college freshman levels. The analog computer is used as a picture-drawing device. How it operates is not emphasized. These circuits have been used several times in presentations made to groups of teachers, and should be of particular interest to those involved in teaching algebra in high school and college freshman classes.