恩梯恩开发出车轮旋转传感器用高磁力橡胶制磁环

恩梯恩（NTN）开发出了用于防抱死系统（ABS）传感器的车轮旋转传感器用高磁力橡胶制磁环。可安装在车轮的轴承上使用。很多汽车的车轮轴承上均装有被称为ABS传感器的车轮旋转传感器．ABS传感器由磁性检测传感器和环状磁环构成。     

基于AT89C55的全自动便携式线束检测装置

针对目前线束生产中多导线插件制作检测困难的问题,提出基于AT89C55的全自动线束检测装置,该装置可以自动检测多导线之间的错连、短路和断路,能自动报警,并在中文液晶屏幕上指出错误的线号,并指明正确的连接方式,为线束现场检测提供了一个结构简单、性能可靠、成本低廉的解决方案.     

油气管道高速漏磁检测系统中传感器研究和设计

为了提高漏磁检测的精度,文章研制了一种用于油气管道漏磁检测系统中的电磁感应式传感器,该传感器安置在二维高速漏磁检测装置中,实现对油气管道缺陷信号的实时检测,获得管道的缺陷信号.介绍了传感器的结构,带磁汇聚装置的磁化系统装置;设计实验与普通的霍尔传感器的检测精度进行分析比较.试验结果表明该传感器在高速管道漏磁检测中能够检测到微小缺陷,比霍尔传感器有更高的灵敏度.     

一种先进的磁环取能的压接式IGBT驱动方案

在高压输电、船舶逆变等应用场合,由于电压很高,系统对分立器件的绝缘性能有更高的要求。现有方案通常采用多层级隔离方案,或者将隔离变压器绝缘做大,这些极大增加了系统复杂程度和设计成本。磁环取电式驱动方案使用具有高绝缘性能的单根多芯硅胶导线穿过需要供电的副边驱动组,导线两端均接在原边电流源的输出端子内。通过控制流过硅胶导线的...     

精细表面下细小缺陷的磁光涡流成像实时探测

磁光涡流成像检测装置可实现精细表面下细小缺陷探测。在该装置中，通过物体表面上方的交流激励线圈实现传统的涡流感应，涡流所感应的磁场由法拉第效应来检测。为了实现表面下缺陷的检测目标，激光穿过安放在激励线圈中的特殊的磁光晶体，激光偏振方向在晶体中的旋转大小取决于检测区域磁场的大小，缺陷将使检测区域磁场分量发生变化并使偏振光的旋转角发生相应变化，通过一光学装置转化成“明”或“暗”图像，该光学装置由传统的显微镜、照明系统、偏振器和CCD图像传感器组成。给出了初步的实验探测结果。     

基于DSP的声磁EAS系统设计

针对射频EAS系统的低检测灵敏度、高误报率等缺陷,设计了一种基于DSP的声磁EAS系统。阐述了系统检测装置的硬件结构及工作时序,分析了声磁标签信号的特征,提出了一种声磁标签信号的检测方法。经过实验测试,系统的抗干扰性能、检测率、误报率等特性都比射频系统有显著的改善。     

一种多用报警器

现在许多家庭把储水器放在楼顶,等水晒热后,可用于洗澡等目的。本装置用于容器水满信号报警,使用几年来效果很好。摩托车等贵重物品的防盗报警也是比较急需的,如果用一根导线穿过车的前轮或后轮,只要把导线剪断,报警器就发出报警音响信号。本报警器可作为水位报警、门铃、摩托车等防盗报警装置,它的特点是简单、可靠、省电,两节5号电池连续使用可     

短路法修理彩电行扫描电路

导致彩电主电源电压下降的原因通常是电源本身和行扫描电路故障。由于行输出级电路工作电压高、电流大,故障率很高,故本文仅讨论由行扫描电路故障引起的主电源电压下降的检修方法。行输出级电路故障常由直流短路或交流短路引起,检修时应先分清属于哪种原因,确定故障范围。这里介绍的短路检查方法就是将行激励管基极和发射极短路。众所周知,行激励管、行管工作在脉冲开关状态,由行振荡级产生的行频脉冲信号推动,只要将行激励管基极和发射极用导线短路(对前级是安全的),这时行激励信号被短路,行扫描电路短路点之后处于静态直流工作状态,行激励管和行管正常时将同时处于截止状态,行输出级不工作。如果主电源电压未恢复正常,故障元件多为行管本身、阻尼二极管、S校正电     

使用轴流风扇散热莫忘防干扰

用小风扇对设备中的电子元器件强制散热效果很好.在安装风扇时,有一个环节往往被忽视,即在风扇电机电源线上应串绕上一只高频磁环以抗干扰.这是因为一般的轴流风扇内部都采用无刷磁敏步进式电机,电机内置有一个脉冲产生、驱动电路,电机被驱动时,这些脉冲成分很容易直接顺电机电源线"外溢",从而对外部其它电器电路构成干扰.视频设备上干扰表现为横通斜线,音响设备上会产生噪音.而串绕上磁环后(如附图),这些干扰成分会立即被有效滤除.连线在磁环上串绕的匝数一般只需绕上1～3匝即可.     

磁后坐电机检测装置的光电测速方法

针对原有磁后坐电机检测装置标定方法_存在测试误差大、步骤繁琐等缺点,提出用光电探测方法对磁后坐电机检测装置进行精确标定,并对该装置加力板速度进行测试.该方法通过机械运动,将光信号转换成电信号,通过滤波放大得到精确的电压脉宽信号,即时间信号,这个时间信号就是计算用的时间,再用遮光板宽度换算,得到该装置加力板的速度.测试结果表明:该方法测试精确、简洁方便,是一种有效可行的方法.     

交变磁场传感器法拉第屏蔽的研究

为了更有效的接收所需信号,我们除了进一步提高传感器本身的性能外,还要消除一些不必要的干扰.在检测低频交变磁场而且磁场信号极其微弱时,首先要选用高性能的交变磁场传感器将交变磁场信号转换为电信号,然后采用一系列的选频放大等电子技术,这样在两者之间就会产生不必要的电场耦合,影响对有用信号的准确测量,为了阻断该电场耦合,对交变磁场传感器采用法拉第屏蔽是不可或缺的重要环节.     

TSV结构对环形物质波波导的影响

由于需要外部电源的接入,传统芯片上的环形结构的物质波波导无法形成完全封闭的环形结构,其产生的环形磁阱存在天然缺陷,阻碍了对冷原子的有效操控。利用硅通孔(TSV)技术能够在垂直于原子芯片表面方向接入导线,有望降低接入导线对环形磁阱的影响。本文通过有限元方法对基于TSV技术的环形原子物质波波导进行仿真研究,对导线加载电流时的磁场进行仿真分析,并系统研究了TSV横截面形状、通孔深度、通孔间隙等因素对环形导线所产生磁阱的影响。最终结合仿真结果,设计一种在加工工艺上切实可行的基于TSV结构的环形波导原子芯片。     

Integrated optic error detecting circuit using Ti:LiNbO3interferometric light modulators

An electrooptic error detecting circuit is proposed and demonstrated which is constructed by integrating an array of waveguide interferometers with multielectrodes. When the electric signals corresponding to the error detecting codes are applied to the present device, the error detection signals are obtained as optical signals from the waveguide outputs. From these optical outputs it is found whether the input signals include errors or not, and which bit, if there is any error, is an error bit. The performance is confirmed by using an experimental device for seven-bit Hamming codes.     

The tether solution [space propulsion, electrodynamic tether]

Current-carrying wire tethers are promising a cheap and reliable means and propelling spacecraft. The electrodynamic tether is a current-carrying wire that harnesses the force exerted by Earth's magnetic field. The propellant-free device could one day have several uses: to transfer working satellites to new orbits; remove defunct satellites from orbit; keep the International Space Station aloft, and even power missions to the outer planets. The technology may also be used aboard the Russians' Mir space station. An important test of the electrodynamic tether will take place in December 2000. NASA's US $7 million Propulsive Small Expendable Deployer System (ProSEDS) experiment will show that an 11 kg, 5 km-long, 1.2 mm-diameter aluminum wire can rapidly remove a rocket's upper stage from orbit. The author describes basic principles of electrodynamic tether thrusters. The Earth's magnetic field exerts a force on and accelerates the wire and hence any payload attached to it. The direction of current flow through the tether, either away or towards the Earth, determines whether the magnetic force will add to or subtract from the tether's orbital energy, and therefore raise or lower its orbit     

Theoretical studies and experimental results of a SMES used in apulsed current supply

A superconducting magnet energy storage (SMES) can be used as a pulsed power supply. A superconducting coil stores energy without electrical losses and this energy can be recovered through a second wire on which the charge (electromagnetic launcher, for example) is linked. The design of such an apparatus needs to solve simultaneously thermal, magnetic, and electric equations. We proposed a three-dimensional finite difference method to solve these coupled problems. This tool enables us to describe resistive zones of expansion in thick coils during a quench and to predict the duration and the efficiency of the discharge. Moreover, it indicates if the coil is prevented from an excessive temperature increase. Then, a probative device is described and experimental results are compared with theoretical ones     

Partial-response coding, maximum-likelihood decoding: capitalizing on the analogy between communication and recording - [History of communications]

Signal processing and coding technology for digital magnetic recording is the core technology of the channel electronics module in a hard disk drive (HDD) that processes signals read from magnetic media. In this historical review I focus on what is now widely known as partial-response, maximum-likelihood (PRML) technology, which takes advantage of the inherent redundancy that exists in signals read out of magnetic media; its theoretical foundation goes back to 1970, and it capitalizes on the analogy between high-speed data transmission and high-density digital recording, and that between a convolutional code and a partial-response signal. The first PRML-based product was introduced by IBM in 1990, and PRML technology soon became the industry standard for all digital magnetic recording products, ranging from computers' HDDs and tape drives to micro hard discs used in PCs, mobile phones, and MP3 players; use of the PRML principle has recently been extended to optical recording products such as CDs and DVDs. Its improved version, called NPML (noise-predictive, maximum-likelihood), and variants have been adopted by the HDD industry since 2000. Today, a large number of communication and information theory researchers are investigating use of advanced techniques such as turbo coding/decoding to further improve the density and reliability of both magnetic and optical recording systems.     

输电线路防外力破坏预警技术应用研究

针对输电线路防外力破坏实用化问题,设计了输电线路防外力破坏预警系统。系统硬件以MSP430芯片为基础,检测装置利用球形工频电场传感器获取电场数据,通过低功耗无线射频将电场数据发送到报警装置,报警装置进行数据处理并通过GPRS传输数据到监控中心。介绍了检测装置和报警装置的硬件和软件设计流程,并介绍了后台管理系统和监控APP。通过对110KV和220KV输电线路进行现场试验验证,该系统运行良好,能够对输电线路的外力破坏进行预警。     

Saving Mir with a rope trick

Using a fabled “skyhook” of engineering folklore (known as firefly), Russia's ailing Mir space station may soon lift itself by its own bootstraps into a higher, more stable orbit. That feat, though, is raising fears at NASA that the development of its supposed replacement, the International Space Station (ISS) will be upset. At present, Mir is orbiting without a crew. The last two cosmonauts to visit the station returned to Earth in June 2000. The next crew is set to go up in November 2000, according to MirCorp, the private consortium that agreed to lease the station for commercial purposes. What's more, in an effort to add years to the station's lifespan, cosmonauts will begin testing a new propulsion technology some time later this year or next. The heart of the new technology is an electrodynamic tether, a long thin wire that will attach to Mir and draw electrons from Earth's ionosphere. As with an electric motor, this current-carrying wire will experience a force as it passes through Earth's magnetic field, a force that will, it is hoped, stabilize Mir's altitude     

关于新型电力检修作业地线装置的研究

电力检修作业是电力供应系统正常实施电力输送的重要途径,也是保障我国电力结构体系逐步实现现代化发展的有效途径,本文基于新型科技手段的创新应用的基础上,对新型电力检修作业地线装置的设计原理与实际应用进行研究,为我国电力事业的创新发展提供理论支持.     

基于磁流变制动器的自供能式汽车线控制动系统的设计与分析

磁流变液是近年来研究的热点,如今汽车线控技术的不断成熟和发展,利用传感器,控制元件,电子元件驾驶员动作转化为电信号,通过电线传递指令来操纵汽车,而不再需要传统的复杂的机械和液压连接装置.针对新型智能流体材料——磁流变液,我们将其应用于汽车线控制动系统中.利用磁流变液的这一特性设计出的制动器,再辅以合理的控制和信息反馈系统,可以实现制动力与地面附着力的快速匹配,甚至可以完成连续精准无脉动的ABS制动过程,从而代替传统液压机械式ABS,有利于实现底盘集成控制,大幅改善车辆制动性能.