具有故障定位能力的健壮故障安全系统

本文以广义故障安全系统理论、数字电路的并发差错定位概念为基础,提出了一种健壮故障安全系统理论.一个基本健壮故障安全电路是由一个实现电路基本功能的基本功能电路和一个差错定位转换器所组成的.健壮故障安全电路具有并发差错定位能力.文中定义了表征健壮故障安全电路和差错定位转换器的基本特性;证明了基本功能电路与差错定位转换器互连,以构造几种具有不同健壮故障安全特性的基本电路所需满足的条件;最后还用电路实例说明了该理论的应用.     

直扩系统PN码捕获和跟踪的FPGA实现

在数字匹配滤波器和超前滞后鉴相环路的理论基础上,采用VHDL编程,在FPGA芯片上实现PN码捕获和跟踪的电路。详细讨论了各电路模块的设计实现方法。完成电路的仿真验证,给出了仿真波形。结果表明电路工作正常可靠,系统扩展方便灵活,满足设计要求。     

多功能非接触止闹数字钟

本系统易懂，简练．非常实用，且电路模块具有通用性，非常适合广大电子爱好者习作和广大专业人士参考：本系统分为6个模块：直流电源、单片机控制模块、键盘控制模块、8位数码管显示模块、光耦传感模块、闹铃模块：系统功能多，所含知识丰富。程序简单。笔者用C语言编写的程序通俗易懂．通过该电路您还可以进一步了解单片机的应用扩展功能和指令使用技巧。     

单方向分离式母板互联设计技术

针对电路模块的功能扩展带来的模块对外接口不足的问题,通过对分离式母板互联技术研究,确定了结构上分离的母板互联形式,主要对单方向分离互联母板互联设计、结构设计、印制板设计、可靠性设计等设计技术展开探讨,从一个角度解决了传统母板限制电路模块功能扩展带来的互联问题,实现了电路模块功能的有效扩展。     

无线传感器网络节点模块化的接口电路设计

为了完成测试任务,传感器节点采用模块化设计。为了实现各模块间方便、快速地通信,依据可编程逻辑器件CPLD编程灵活,在部分功能模块内扩展了专用SPI接口电路。试验证明：接口电路工作稳定、模块间可快速便捷通信、系统扩展性强,系统整体性能提高。     

用单片机设计的电子琴

本设计易懂、简练，所用器件常见，上网查询资料方便，电路模块具有通用性，非常适合广大电子爱好者制作。本电子琴系统以SST89E564RD为中心，融合了82C79可编程键盘，LED接口电路模块、存储扩展模块、喇叭驱动控制模块，以简单的硬件电路和相对复杂的软件来实现，图1为其原理图。     

基于Q2403A的单片机短消息收发系统

本文提出了基于Q2403A手机模块的单片机短消息收发系统设计方案。该系统由硬件和软件两部分组成。硬件系统主要有Q2403A外围电路、单片机扩展电路及RS-232总线接口电路;软件部分主要有PC与单片机通信,短消息收发两部分组成。     

光电跟踪系统控制器硬件设计

为了提高光电跟踪系统控制器的性能,文中对光电跟踪系统控制器的硬件部分进行了设计。首先给出光电跟踪系统控制器硬件电路框图。接着介绍最小系统的设计方案,其中包括存储器扩展,外部时钟,复位电路,电源电路,CPU板的抗干扰分析与设计等部分。最后对模拟量、数字量模块和通信模块设计进行了详细阐述。采用该控制器不仅增强了光电跟踪系统的灵活性和适应性,保证了系统性能要求,而且还具有良好的实时性。     

测试和测量

CompactRIO平台用于嵌入式开发嵌入式控制和采集平台CompactRIO有嵌入式系统和R系列扩展系统两种配置。嵌入式系统包含一个实时的嵌入式处理器、4个或8个插槽的可重配置机架,机架包含一个用户可编程的FPGA与10个热插拔工业I/O模块,每个I/O模块包含内置的现场接线连接器、信号调理与变换电路和一个可选的隔离装置。扩展系统为PCI或PXI/CompactPCI R系列FPGA器件提供高性能的信号调理与工业扩展I/O,I/O模块的瞬时隔离电压为2300Vrms,连续隔离电压为250Vrms。工程师可通过LabVIEW、LabVIEW实时模块和LabVIEW的FPGA模块…     

气动发动机的电控系统设计

文章介绍了基于ATmega16的气动发动机电控系统设计,经试验证明该电控系统可以实现对气动发动机的有效控制.文章设计了信号采集处理模块、电磁阀驱动模块和CAN通讯模块等的硬件电路,采用模块化方式的控制软件设计,并建立了基于CAN总线的网络通信平台以便系统扩展,还提出了完善电控系统的建议.     

电子线路综合实验模块设计

该文提出了电路基础实验模块化的思想,给出7个基础实验模块的电路设计图,并给出了由这7个模块组成的两个小型综合实验电路系统的设计框图。在基础电路模块设计中充分考虑器件的通用性,提高实验的可行性,并与理论课的相关内容紧密结合,加深学生对基础理论的理解;在综合实验电路设计中既包含模拟电路的内容,又包含数字电路的内容,充分体现电路的综合性,并增加实验的趣味性,启发学生的创新意识,提高学生的综合电路设计能力。     

LVDS接收器的失效保护电路设计

提出了一种用于LVDS(Low Voltage Differential Signal)接收器的内置失效保护电路.它能在接收器输入开路、短路和接负载的三种情况下,使输出保持高电平状态,而不受这三种非正常输入的影响.着重分析了这种内置失效保护电路的电路结构以及工作原理,并给出了用Spectrc进行模拟验证的结果.     

A Hot-Swap Solution for Paralleled Power Modules by Using Current-Sharing Interface Circuits

A hot swap of power modules is required by high-availability parallel power module systems. With the hot-swappable paralleled power modules, the system up-time can be maximized, the system maintenance and repair can be simplified, and the system upgrade can be allowed for. In this paper, a simple hot-swap solution is proposed for the paralleled power modules which use current-sharing (CS) interface circuits to do the CS work. By redesigning the basic function circuits of the CS interface circuits (such as the under voltage protection circuit, the current-sharing circuit, and the light load protection circuit etc.), an additional hot-swap function can be implemented "parasitically". There is no extra hot-swap controller and no compatibility problem between the hot-swap and CS solutions used. A prototype CS interface circuit with a "parasitic" hot-swap function was designed, implemented, and tested. The results show that the proposed hot-swap solution is feasible and suitable     

非固有耐短路、无危害式安全变压器的短路和过载保护试验

作者结合工作心得,对非固有耐短路、无危害式安全变压器的短路和过载保护测试方法进行了总结和归纳.     

一类基于比较原理的安全冗余结构及FSC方案

本文提出了一类基于比较原理的安全冗余结构：Ｎ模比较混合冗余结构，并设计了一种用通用二值逻辑器件构成的两输入故障安全比较器。该ＦＳＣ可以和通用计算模块在系统构成安全ＮＭＨＲＣ结构。     

Evaluating the safety of self-checking circuits

In this paper, we consider the evaluation of the safety of a self-checking circuit with combinational logic. Since the circuit is tested under normal operation, it may stay in different states such as a perfect state in which any erroneous output can be detected, unstable states in which an erroneous output may be detected or may not, a safe-state when the erroneous output has been caught, and a fail-state because the erroneous output is undetected, as time goes on. Consequently, we propose a fail-safe evaluation, using a Markov model to describe the state transitions and predicate the probability of the circuit not being in the fail-state.We include a comparison with existing evaluation methods, the proposed approach being more practical because it estimates the safety of the circuit, which is reducing as time goes on, instead of giving a constant probability measure.This work was supported in part by Research Grant No. 5711 from the Natural Sciences and Engineering Research Council of Canada and by an equipment loan from the Canadian Microelectronics Corporation.     

Theory of differential current switches and logic design of ternary ECL circuits at switch level

Starting from the viewpoint that the switch states and signal values in a digital circuit should be described separately by two different kinds of variable, the interaction between the switching element and signal in multi-valued ECL circuits is analysed and two types of connection operations, threshold switching operation and current switching operation, are proposed. The properties and circuit realizations of these new operations are discussed and the theory of differential current switches applicable to ECL circuits is established. Examples of basic ternary ECL circuits confirm that this theory can effectively guide the logic design of ternary ECL circuits at switch level. The circuits are verified by using the SPICE II program. They have the same logic level difference and transient characteristic as binary ECL circuits. Since the multi-valued ECL circuit uses only one set of power supply and can set several threshold values by using reference levels, it can be fabricated using conventional ECL techniques and is compatible with binary ECL circuits.     

A Power Conditioning Stage Based on Analog-Circuit MPPT Control and a Superbuck Converter for Thermoelectric Generators in Spacecraft Power Systems

A thermoelectric generator (TEG) is a very important kind of power supply for spacecraft, especially for deep-space missions, due to its long lifetime and high reliability. To develop a practical TEG power supply for spacecraft, a power conditioning stage is indispensable, being employed to convert the varying output voltage of the TEG modules to a definite voltage for feeding batteries or loads. To enhance the system reliability, a power conditioning stage based on analog-circuit maximum-power-point tracking (MPPT) control and a superbuck converter is proposed in this paper. The input of this power conditioning stage is connected to the output of the TEG modules, and the output of this stage is connected to the battery and loads. The superbuck converter is employed as the main circuit, featuring low input current ripples and high conversion efficiency. Since for spacecraft power systems reliable operation is the key target for control circuits, a reset–set flip-flop-based analog circuit is used as the basic control circuit to implement MPPT, being much simpler than digital control circuits and offering higher reliability. Experiments have verified the feasibility and effectiveness of the proposed power conditioning stage. The results show the advantages of the proposed stage, such as maximum utilization of TEG power, small input ripples, and good stability.     

基于饱和非线性模块的多涡卷混沌电路

针对分立元件构造的多涡卷混沌电路存在电源电压高、耗能多、频谱范围窄、电路体积大的问题,采用跨导电容结构,设计了一种将非线性模块、跨导器、电压反相器集成于一体的多涡卷混沌电路。非线性模块呈现饱和特性,通过调节电流源和MOS管宽长比来改变其特性曲线的转折点、饱和值、斜率,方便地构造出分段线性函数电路。设计了网格多涡卷Jerk系统和单方向多涡卷Chua系统,采用非线性模块分别搭建了Jerk系统中的阶梯波函数电路和Chua系统中的三角波函数电路。Pspice仿真结果证明了搭建的非线性模块和混沌电路设计、电路功能的正确性。