利用水的导电特性实现水位数字化自动检测

含有电解质的水溶液在外施电场的作用下是可以导电的,将水的导电特性这一物理现象与数字电子编、译码技术相结合,提出了一种新的数字化水位自动检测途径和随之而产生的一个新的应用科学研究领域,并具体讨论了如何应用MOTORORA公司生产的集成编、译码芯片MC145026/28实现对水位的数字化自动检测电路及其工作原理.该方法的提出对于在恶劣的环境下进行水文水位检测将具有十分重要的应用价值.     

用单片机M68HC11实现MC145026编码功能

通过对专用编／解码芯片MC145026／MC145027功能和工作原理的分析说明,介绍了采用单片机M68MC11实现编码器功能的方法,该方法充分利用了单片机的编程功能,有效的节省了I／O端口资源。     

集成开关电源控制器MC34063的原理及其应用

MC34063是一种微功耗的新型集成开关电源控制器,利用它可方便地组成各种形式的直流变换电路,而且具有外围元件少,功耗低,体积小和调试方便等优点。本文主要介绍集成开关电源芯片MC34063的原理和应用电路的设计,最后简要地说明该芯片的实际应用线路。     

双PLL集成频率合成器

介绍双PLL集成频率合成器芯片MC145149的应用方法,以及用它构成高速跳频频率合成器的电路设计原理.     

MC145026和MC145027编译码器多路遥控系统传输速率的计算

<正> MC145026和MC145027组成的编译码器既可用于多路遥控,又可用于数据传输,使用简便可靠,但其编码的传输速率各类手册均未作介绍.本文将根据编译码器原理和笔者实际测试结果推导出传输速率的计算公式,为系统设计提供参考.系统的典型设计如图1,MC145026编码器可对9行输入信息(地址A_1～A_5、数据D_6～D_9)进行编码,每位输入数据编码后用两个脉冲表示:“1”编码为两个宽脉冲;“0”编码为两个窄脉冲;“开始”编码为一宽一窄脉冲.编码后的数据流由D_0串行输出.MC145027译码器接收MC145026输出的编码数据流,当     

CVSD及其在井筒数字话音通信中的应用

介绍了连续可变斜率增量调制（CVSD）实现模拟信号数字化的原理及在井筒数字语音通信中采用Motorola公司生产的单片CVSD集成芯片MC34115实现数字编码电路的设计方法     

单片机的无线数据通信

利用Motorola公司的遥控用编/解码芯片MC145026和MC145027,实现两台单片机间的无线数据通信.     

一种电容传感器金属材料表面缺陷检测方法

基于电容传感器原理,实现了一种简单有效的金属材料表面缺陷检测方法.首先介绍了电容传感器的工作原理,描述了单电极传感器用于检测金属材料表面缺陷时的基本方法,并给出了相应的电路模型.设计了系列实验验证该检测方法的可行性.实验结果表明：电容传感器对金属材料表面缺陷较敏感,通过单片集成电场成像集成器件MC33794能够快速简单实现该检测方法,为金属材料表面缺陷（如腐蚀）提供了一种快速、便捷、有效的检测方法.     

大话改装2008 我的电脑我做主

2008年8月,《电脑爱好者》众编邀我到编辑部小坐,顺便看8日晚上的奥运开幕式。我欣然前往。因为三年前做电脑改装专题的时候我们约定,请他们测评我的“MC”。什么是“MC”?哦,忘了解释了,是Mini-Computer的缩写,全称叫“微型随身电脑”。以前不是有什么PC、NC吗,现在都停止批量生产了,只有一些机关、办公室在用。这款MC是我发挥无限创意、历时三年改造设计的电脑,争取通过测评后,让《电脑爱好者》来个独家报料,并且搭乘奥运商机批量上市,全球统一定价为18888元。我们的目标是:让MC成为笔记本电脑的终结者!当帅气的我一身休闲装、赤手空拳(别误会,不是来打架的)来到编辑部时,小编、老编、老老编的目光由期待转为疑惑。我忙解释:“不好意思,来的匆忙,没带礼品!”Sunny上看下看左看右看,见我连个公文包也不带,第一个发问:“礼品带不带没关系,你不是说好了带样机测评吗?我们都准备好了,你不会是忘了带了吧?”我伸手把别再腰里的MC拿出来,放在桌子上,“这就是我的MC,代号中国龙!”     

读编心语

HD Labs读编对对碰 HD Labs（MC高清实验室）栏目从去年成立以来,受到了各位读者的强烈关注,但是同时,大家对HTPC的热情却掺杂着一半海水和一半火焰,今天,玛丽欧特邀MC众位评测工程师坐客“读编心语”,和读者朋友们一起就“高清”摆一下龙门阵。     

Built-In Self-Test Trends in Motorola Microprocessors

The first built-in self-test feature in a Motorola sidered a ?wart? until a RAM test application recast it as a ? feature.? Though the BIST approach?an idea conceived as a way to reduce production costs for the MC6805 family?did not meet its major design objective, the experience provided impetus for the development of BIST techniques for the MC6804P2, which met most of the objectives intended for the MC6805P2. The Motorola microprocessor family has come to incorporate a growing number of testability features; current devices typically employ a combination of BIST and other techniques. If present trends continue, transistor counts for microprocessor-related parts should approach 10 million within 10 years. The authors argue that structured design techniques offer the most promising prospects for solving the design and test problems resulting from this increase in complexity.     

A Benchmark Comparison of 32-bit Microprocessors

The benchmarking of four 32-bit microprocessors?the MC68020, the NS32032, the AT&T 32100, and the Intel 80386?revealed some specific reasons for the differences in performance that were observed.     

探头固定特性对非介入式压力检测性能的影响

基于超声波的非介入式压力检测是利用超声波在容器壁中的传播时延与容器内压有关这一特性来实现压力检测。获得高信噪比的超声波信号和精确的传播时延是提高压力测量精度的关键。本文采用一发两收（一个发射探头、两个接收探头）模式,研究了接收探头固定特性对超声波信号幅值以及传播时延的影响。实验结果表明,随着探头荷载的增加,超声波信号幅值会随之增大并趋于稳定。此外,改变两个接收探头的荷载大小,超声波传播时延也会随之而变化,而且其传播时延改变量和由压力容器内压所引起的传播时延处于同一数量级。因此,在实际应用中应确保两个接收探头固定特性一致,从而提高压力测量精度。     

基于自抗扰速度调节器的矩阵变换器驱动 永磁同步电机直接转矩控制

针对永磁同步电机（permanent magnet synchronous motor,PMSM）系统,采用矩阵变换器（matrix converter,MC）驱动方式,提出了基于自抗扰技术（active disturbance rejection control,ADRC）的直接转矩控制（direct torque control,DTC）策略．用MC替换常规交—直—交变换器,以提高系统输入侧功率因数（power factor,PF）;用ADRC替换常规电机调速系统中的PI速度调节器,以提高系统的鲁棒性．首先,建立MC驱动PMSM系统的数学模型,并给出ADRC速度调节器和MC驱动PMSM的DTC设计思路和方法．基于ADRC的DTC策略能够使MC驱动的PMSM系统稳定运行,具有较好的转速和转矩控制效果,且输入侧PF能够达到1．然后,将其与基于PI的DTC策略相比较,该策略具有更强的抗负载干扰能力和跟踪给定转速变化的能力．最后,通过仿真实验验证该方法的正确性和有效性.     

Four common multicommunicating misconceptions

Multicommunicating (MC) represents a form of multitasking in which employees such as IS analysts and managers engage in multiple conversations at the same time (e.g., by sending texts while on a telephone call). MC can occur either during group meetings or during one-on-one conversations: the present paper focuses on the latter, termed dyadic MC. MC is increasingly prevalent in the workplace and is often useful in today’s business world, for example by making it possible to respond in a timely manner to urgent communications. Nonetheless, the efficacy of MC behaviors can also be questioned as they have been found to negatively affect performance and workplace relationships, as well as causing stress. During our investigations of this phenomenon, we often heard IS practitioners say ‘So what? I do this all the time, it’s no problem!’ which suggests that certain misconceptions regarding MC behaviors may be prevalent. Arising from research findings in multiple disciplines, we examine four such practitioner beliefs regarding MC behaviors: MC makes employees more accessible, it enhances productivity, it is required in most jobs, and rudeness is not an issue when MC. Further, we suggest recommendations to IS employees and managers so that they can better manage MC.     

基于MC9S08单片机的挖掘机测速仪表的设计

介绍了飞思卡尔MC9S08系列单片机的主要性能特点,给出了MC9S08QG8单片机在挖掘机测速仪表中的应用方法,并就测速仪表的组成、结构、测量原理、算法、软硬件设计作了详细的论述,经实验和实际应用证明了该测速仪表具有精度高、抗干扰能力强、工作稳定性好、性价比高的特点,已在贵州詹阳动力重工有限公司生产的某型挖掘机上装车使用.     

Extended value network modelling and simulation for mass customization implementation

Mass customization (MC) which was introduced by Davis (Future perfect, Addison-Wesley, Reading, MA 1987) has become a reality; nevertheless not all MC stories had a happy ending. Many companies implementing MC failed while some others succeeded such as National Bicycles Industrial Company of Japan, Hewlett-Packard, Motorola, Benetton, Chryslers, and Dell. How to determine the best MC strategy to be implemented or even if such a strategy should be adopted? In the literature many methods for implementing MC are found, however none of these propose a structured way for implementing and evaluating such a strategy as a whole, each concentrated on one department or phase of the supply or value chains. We suggest in this paper the use of extended value network modelling and simulation for evaluating an MC strategy, and we describe the modelling language used and the approach which will be applied into shoemaking industries via a European project named DOROTHY.     

受恶意程序传染的WSNs可生存性评估

为实现传感节点数据高可靠传输的无线传感器网络WSNs（Wireless Sensor Networks）,提出一种针对受恶意程序传染的聚簇WSNs可生存性评估方法。通过使用能预测恶意程序传染行为的博弈模型,将恶意程序传染的故意性与马尔可夫链的随机性关联,实现利用马尔可夫链中的状态转换描述恶意程序传染行为的目的。使用提出的易感节点可靠度评估指标,根据可靠性理论将聚簇WSNs看作一个“并-串-并”系统,推理得到了一个簇、一条路由直至整个WSNs的可靠度评估指标,最终得到WSNs生存期评估指标。实验分析了影响WSNs可生存性的因素,结果表明提出的方法能有效评估WSNs的可生存性,为设计高可生存的WSNs提供理论基础。     

基于事例的敏捷供应链模型构件可重用设计

文章从敏捷供应链集成化企业建模的需求出发,围绕敏捷供应链的相关特点,研究了敏捷供应链的通用化建模方法,结合CIMS_OSA的有关内容,划分了敏捷供应链的建模层次。采用模型构件的方法进行建模,提出了基于事例的模型构件可重用设计方法。研究了模型构件的事例表示方法,并相应地建立了模型构件的匹配算法。     

New Products

A color-display version of the Hewlett-Packard Series 200, MC68000-based technical computer is now available with a system configuration that includes 640K bytes of RAM, dual 5?-inch flexible disks, and Basic and Pascal languages.