一种高可靠性光电开关的实现

介绍了一种高可靠性的光电开关电路 ,带有稳频调制光以抗各种干扰 ,具有大功率驱动电路和光电三极管的自动增益控制特性 ,检测电路的输出级带有放大和施密特迟滞特性 ,确保整机的高抗干扰能力。     

A Simple Learning Control to Eliminate RF-MEMS Switch Bounce

A learning control algorithm is presented that reduces the closing time of a radio-frequency microelectromechanical systems switch by minimizing bounce while maintaining robustness to fabrication variability. The switch consists of a plate supported by folded-beam springs. Electrostatic actuation of the plate causes pull-in with high impact velocities, which are difficult to control due to parameter variations from part to part. A single degree-of-freedom model was utilized to design a simple learning control algorithm that shapes the actuation voltage based on the open/closed state of the switch. Experiments on three different test switches show that after 5-10 iterations, the learning algorithm lands the switch plate with an impact velocity not exceeding 0.20 m/s, eliminating bounce. Simulations show that robustness to parameter variation is directly related to the number of required iterations for the device to learn the input for a bounce-free closure.     

改进一种高压开关联锁电路触发保护的研究

变电所中高压开关的重要作用是通断和保护电路,主要以断路器和隔离开关为主,其动作顺序有严格要求,防止出现误操作造成电路供电中断或烧毁设备,在控制回路中加装联锁功能确保电路运行中按照既定规则完成开关的分合闸操作和信号状态显示。在传统控制回路中改进一种基于IGBT晶体管触发投切装置,有效反馈和检测高压开关与电路运行的安全与可靠。     

基于PIC单片机的高压智能同步开关控制系统

本文介绍其在高压智能同步开关的控制系统中的应用,着重论述了硬件系统的设计。16F87X软硬件资源丰富,需要的外围器件很少,本文详细说明了如何利用16F87X的特性来提高控制系统的精确性和可靠性。     

一种高精度高电源抑制的CMOS带隙基准

本文介绍了一种高精度高电源抑制的CMOS带隙电压基准,电源电压3V.该电路的实现是基于0.6um 5V的CMOS工艺.为了达到较高的精度和电源抑制比,电路中采用了一个PMOS电流源做调整管,以保证基准核的电流恒定.仿真结果表明,该基准电路在低频下的电源抑制比可达到-88dB,温度变化范围从-40℃至120℃.时,温度系数只有3.5ppm,输出电压误差为0.65mV.     

新型高压开关机械特性测试仪的设计与实现

本文介绍了采用单片机80C320和CPLD为数据处理和控制核心的新型高压开关机械特性测试仪的设汁原理和实现方法。本测试仪对不同的高压开关,采用不同的传感器,具有很高的测量精度。     

高压开关机械特性测试系统的设计

研究了高压开关机械特性测试系统的软硬件设计;采用上下位机模式实现高压开关测试、结果计算及显示功能;由ARM、FPGA及信号处理模块组成的下位机系统实现高压开关动作控制和数据采样功能;运行在PC机上的上位机系统主要完成测试指令下发、测试结果计算与显示以及数据保存和读取;上下位机系统通过网络芯片DM9000实现以太网通信协议;试验证明,该系统稳定性好且采样精度高,具有良好的实用价值.     

An accelerated thermal cycling test for RF-MEMS switches

Thermal cycling tests are an important part of the standard space qualification procedure for RF-MEMS devices. Standardized tests are rather demanding in terms of equipment, sample preparation and experimental time. In this paper, we present a fast thermal cycling test aimed at obtaining a rapid selection among different switch geometries in terms of thermal cycling resistance. Seven different switch typologies are examined and tested, evidencing that the most important source of deterioration is the mechanical deformation of the movable membrane due to changes in internal stresses. For this reason, the clamping typology is the most important design parameter to take into account in order to achieve a good thermal cycling resistance. Contrarily to expectations, the cantilever structure is not the most promising switch typology, because while the main part of the movable membrane is stress free, the anchoring part of the structure is on the contrary heavily stressed and modifies with the temperature change. The most promising structure is a four-anchored switch with a flexural clamping structure that allows the thermal expansions in the horizontal direction, while the data for all the clamped–clamped structures investigated are similar and their differences can be interpreted in terms of different distribution of the thermal strain over the whole membrane.     

基于故障树的高压空间电源可靠性研究

本文介绍分析了一种新型高压体系空间电源配电部分的结构特点,运用可靠性分析中故障树的分析方法,针对较复杂结构的电源系统,将系统故障与组成系统的部件故障有机结合起来,并比较了不同部件的重要度。     

中压开关柜智能化技术

介绍中压开关柜的智能化实现方案。     

一种安全可靠的远程在线学习系统

对在线学习进行了研究,提出了独有的系统设计方案,采用了B/S结构,打破了用C/S程序开发量大、系统维护困难、安全性难以保障等局限性;采用ASP.NET技术,解决了在执行效率上受到了在网络用户访问量大时,服务器负担较重的局限性;在安全可靠性方面设计出了一个安全模型,可用于类似的多网在线,效果较好,功能有待进一步完善。     

光电编码器的高可靠性数字译码方案研究

传统的译码电路中,光电码盘输出光电流信号的变化对译码结果及电路使用寿命有严重的影响。本文提出的是一种改进的数字译码电路设计方案,能够有效地降低码盘内部器件老化和各种环境变换引起的误码和装调的复杂度,同时实现电路的通用性,并大大延长了电路的使用寿命。     

An active heat-based restoring mechanism for high reliability RF-MEMS switches

Microsystem Technologies - An active mechanism to retrieve the functionality of RF-MEMS ohmic switches after stiction takes place is discussed. The mechanism exploits a micro-heater, embedded...     

高压组合开关照明保护箱的改进

由于煤矿井下工作环境恶劣,电气设备长时间运行会绝缘老化、受潮、受损,失去绝缘作用,因而经常会出现漏电故障。本文在深入研究这种保护器和操作经验的基础上简化了该照明保护箱,解决了保护箱外壳带电的问题。使其简便,既易于井下工人的操作,又方便检修便于故障点的排查。     

一种改进的高安全性密钥恢复机制

针对用户密钥丢失导致加密数据不可恢复和传统数据库保护数据存在的问题,设计了一种高安全性的密钥恢复机制;该机制通过非对称加密算法、随机密钥加密用户备份信息,以及"一次一密"加密数据库等手段有效解决传统密钥恢复机制在密钥产生、存储、备份、恢复过程中的安全问题;安全性分析表明该方案能够有效地维护密钥的安全,确保除用户以外任何机构和个人都不能获得密钥,同时在用户丢失密钥时,能够安全恢复密钥,具有一定的实践性和推广价值。     

大功率高压变频器的选型

对大功率变频装置的结构、技术性能、控制方式及适用工况进行分析,并就其工程实施及合理选配进行探讨.     

On Dual-Mode Driving Control Method for a Novel Unmanned Tractor With High Safety and Reliability

Due to the non-standardization and complexity of the farmland environment, it is always a huge challenge for tractors to achieve fully autonomy (work at Self-driving mode) all the time in agricultural industry. Whereas, when tractors work in the Tele-driving (or Remote driving) mode, the operators are prone to fatigue because they need to concentrate for long periods of time. In response to these, a dual-mode control strategy was proposed to integrate the advantages of both approaches, i.e., by combing Self-driving at most of the time with Tele-driving under special (complex and hazardous) conditions through switching control method. First, the state switcher was proposed, which is used for smooth switching the driving modes according to different working states of a tractor. Then, the state switching control law and the corresponding subsystem tracking controllers were designed. Finally, the effectiveness and superiority of the dual-mode control method were evaluated via actual experimental testing of a tractor whose results show that the proposed control method can switch smoothly, stably, and efficiently between the two driving modes automatically. The average control accuracy has been improved by 20% and 15% respectively, compared to the conventional Tele-driving control and Self-driving control with low-precision navigation. In conclusion, the proposed dual-mode control method can not only satisfy the operation in the complex and changeable farmland environment, but also free drivers from high-intensity and fatiguing work. This provides a perfect application solution and theoretical support for the intelligentization of unmanned farm agricultural machinery with high safety and reliability.      

高集成度超声相控发射电路的设计

以往超声相控发射电路采用分立元件,集成度低,由多块发射电路板组成,存在由于板间不同步造成的误差,影响发射精度.本文提出了一种高集成度高精度发射电路的设计.该设计利用FPGA内部锁相环的倍频和移相的技术取代了延时线,并采用多个4通道的高压脉冲产生芯片和8通道高压模拟开关芯片,集成于一块电路板上,大大提高了电路的集成度,避免了板间不同步的问题.同时对该电路实现电子扫查进行了相控分析,并通过仿真和实验,证明了电路的可行性.     

高压变频器主从控制在高压辊磨机中的应用

分析高压辊磨机的运行工艺和传动特性,结合高压变频器主从控制技术,介绍高压辊磨机双电机同步控制的技术解决方案和实际运行效果。     

采用MOSFET的高速截流开关

用P -MOSFET构成快速截流电子开关 ,将其串联在负载与直流电源之间 ,在负载电流超过允许值时 ,迅速中断供电 ,从而组成具有“本质安全”输出特性的直流电源。该电源可在有爆炸性气体存在的环境中工作。