8279可编程接口电路扩展应用的设计

分析了８２７９可编程键盘／显示接口电路的工作原理，纠正了关于按一次键引起多次中断请求的误解，介绍了８２７９接口电路在控制系统中的两种扩展应用的设计方法。     

CPLD与16C554在航空发动机参数采集器中的应用研究

依据高性能和小型化的要求,阐述了DSP在航空发动机参数采集器硬件系统设计中的应用。以TMS320C31DSP为处理核心,采用复杂可编程逻辑器件(CPLD)对外围扩展电路(A/D、串口扩展芯片16C554和外部存储器等)进行片选和中断控制,从而提供了丰富的模拟接口、方便灵活的数字接口和串行通信接口。利用16C554扩展串口,其硬件接口电路简单;利用复杂可编程器件CPLD设计DSP扩展外设电路的译码电路,可以使设计者在系统内进行编程。本文给出了主要器件具体的硬件选型,并结合其特点阐述了它们在航空发动机参数采集器中的硬件连接及软件操作方法。     

基于FPGA的存储测试系统的双通信接口实现

针对大多以单片机和CPLD构建存储测试系统的方案中,器件多、设计繁、系统稳定性差及无扩展外设等问题,提出了在FPGA中利用VHDL语言实现SPI接口设计和USB接口设计的存储测试系统构建方案,使得那些没有SPI接口功能的控制器或处理器等也能通过SPI接口与外围设备进行数据交换并且复杂可编程逻辑器件(FPGA)能控制信号的有效采集及存储。实验证明:SPI接口可方便地与无线及多种智能仪器对接,便于FPGA扩展EEPROM,外接LED显示器等,USB接口可实现数据的快速稳定传输。     

基于智能数据采集芯片的小型可编程控制器

根据小型污水处理厂对污水处理测控系统的需求,使用内嵌8路12位ADC的Flash MCU ADμC812,设计了基于I~2C总线扩展接口的微型可编程控制器。该可编程控制器具有配置简单、扩展方便和造价低廉等优点。用户可使用梯形图、语句表、汇编语言和C语言编写用户程序。     

中小型污水处理的微型PLC的设计与实现

根据中小型污水处理厂对污水处理测控系统的需求,使用内嵌MCU和多路12 bit ADC的ADμC812,设计了基于I2C总线扩展接口的微型可编程逻辑控制器.该可编程逻辑控制器具有配置简单、扩展方便和造价低廉等优点.用户可使用梯形图、语句表、汇编语言和高级语言编写应用程序.     

用8259A扩展8031单片机外部中断源的方法

MCS—51系列单片机能提供给用户自由用作不同用途而不是指定用途的外部中断源只有两个。在需要有多个外部中断的应用场合,需要给单片机扩展外部中断源。用8259A可编程中断控制器接口实现8031外部中断源扩展的方法看似简单,实则存在着一些需要认真考虑和解决的问题,本文讨论了这些问题以及具体的解决方法,给出了接口电路和相关源程序结构。     

基于可编程逻辑器件的串行外设接口设计及实现

论述了串行外设接口(SPI)的原理,扩展了多从/多主模式、线与等新功能.用VHDL语言设计了全部源代码,在Max plusⅡ集成开发环境下对VHDL源代码进行编译、综合,并由可编程逻辑器件(CPLD)实现.使SPI接口应用的灵活性得到提高.     

基于PCI的运动控制卡SMP330应用技术

SMP330是一个用于数控设备编码器解码接口的PCI插卡，其核心部分是一个基于CPLD（复杂可编程逻辑）的编码器解码接口SOPC（系统在可编程芯片上）芯片：SM2100，主要提供了1-4路AB相编码器信号的解码及PWM输出功能，用于对实际位置的判断与反馈。SMP330的高性价比特点非常适合应用于现阶段我国数控设备中。     

可编程增益放大器在小信号数据采集系统中的应用

首先介绍了可编程增益放大器的概念，特点和作用，然后给出院 一个基于PC机ISA总线的数据采集卡，利用AD526实现的可编程增益放大器及与A/D模块和总线间的接口电路，并讨论了设计中应注意的事项。     

基于ISP技术的自动测试系统测控接口设计

采用系统可编程（ISP）技术，将测控接口复杂的逻辑电路划分为地址选择及译码、数据选择及输出锁存、输入／输出及中断控制，可编程计数器，调试信号模拟等功能模块。在ispDesign Expert平台下，采用自上而下的设计方法，分别利用原理图和VHDI语言描述电路结构和各功能模块的逻辑，在一片ispLSI3320上实现了整个测控接口的逻辑功能，不仅使测试系统集成度和可靠性提高，而且具有调节信号仿真功能，使系统的设计和调试过程简化。     

固定型VRLA电池负极失效问题

应用SEM对阀控式密封铅酸蓄电池在循环过程中不同阶段的负极物质的微观结构进行了观察 ,发现有机膨胀剂的损失是导致负极活性物质出现不可逆硫酸盐化现象的主要原因。通过对负极物质配方的调整及充电方法的改进 ,能够有效地抑制负极硫酸盐化现象的出现。     

Refrigeration generation using expander-generator units

The problems of using the expander–generator unit (EGU) to generate refrigeration, along with electricity were considered. It is shown that, on the level of the temperatures of refrigeration flows using the EGU, one can provide the refrigeration supply of the different consumers: ventilation and air conditioning plants and industrial refrigerators and freezers. The analysis of influence of process parameters on the cooling power of the EGU, which depends on the parameters of the gas expansion process in the expander and temperatures of cooled environment, was carried out. The schematic diagram of refrigeration generation plant based on EGU is presented. The features and advantages of EGU to generate refrigeration compared with thermotransformer of steam compressive and absorption types were shown, namely: there is no need to use the energy generated by burning fuel to operate the EGU; beneficial use of the heat delivered to gas from the flow being cooled in equipment operating on gas; energy production along with refrigeration generation, which makes it possible to create, using EGU, the trigeneration plants without using the energy power equipment. It is shown that the level of the temperatures of refrigeration flows, which can be obtained by using the EGU on existing technological decompression stations of the transported gas, allows providing the refrigeration supply of various consumers. The information that the refrigeration capacity of an expander–generator unit not only depends on the parameters of the process of expansion of gas flowing in the expander (flow rate, temperatures and pressures at the inlet and outlet) but it is also determined by the temperature needed for a consumer and the initial temperature of the flow of the refrigeration–carrier being cooled. The conclusion was made that the expander–generator units can be used to create trigeneration plants both at major power plants and at small energy.     

Spectral narrowing and temporal expanding of femtosecond pulses by use of quadratic nonlinear processes

A nonlinear system capable of expanding pulse with spectral narrowing, an analogy to a spatial beam expander in linear optics, is studied theoretically and experimentally. The system, with features of high efficiency and maintaining near Fourier-transform limit (FTL), is constructed by using quadratic nonlinear processes with chirped pulses. The spectral and temporal characteristics of such a pulse expander are investigated analytically and computationally. It shows that group-velocity mismatch of nonlinear crystal plays a detrimental role, which leads to a deviate operation of pulse expander from its ideal case, e.g., temporal shortening, spectral broadening, and a deviation from the FTL of the expanded pulses. The criteria for designing a near aberration-free pulse expander are given based on these analyses. As a demonstration, we experimentally expand broadband 70-fs pulses from a Ti:sapphire regenerative amplifier to narrowband 60-ps longer pulses. The conversion efficiency from pump to idler of the nonlinear pulse expander is currently limited to a few percent and can be practically improved to 10% to 20%.     

基于PLC和触摸屏的膨胀机控制系统改造

通过使用可编程序控制器和触摸屏对膨胀机的控制系统进行改造。改造后解决了膨胀机控制系统存在的问题,保证了控制系统的可靠性,增强了控制系统的操作性。     

新型合成有机膨胀剂对阀控铅酸电池性能的影响

研究了新型合成有机膨胀剂对电池性能的影响。试验中发现 :新型合成有机膨胀剂能提高充电接受能力、克服早期容量衰减 ,而且有利于高倍率起动放电     

焊接冷凝管在役断裂原因分析

分析了失效的焊接冷凝管裂源处断口、成分及显微组织，认为沿晶界析出的碳化物导致材料局部晶界脆化，熔合线处的沟槽造成应力集中，以及在生产和使用过程中产生的作用于焊管的应力等的共同作用是导致焊接冷凝管在役断裂的主要原因。     

金属膨胀器质量与工艺的改进

介绍了互感器用膨胀器常见的质量问题；提出了膨胀器反渗漏措施及提高其清洁度和除氢效果的工艺要点；探讨了膨胀器工况示值的标定，并对其专业标准提出了修订意见。     

A Fuel-Free Trigeneration Plant at Stations for Technological Reduction of Transported Natural Gas Pressure

A new original basic process circuit of a fuel-free trigeneration plant simultaneously producing electricity, heat, and cold is considered. The plant can be used at technological transported gas pressure reduction stations instead of throttle devices conventionally used for this purpose. The plant process circuit involving, as its key components, an expander–generator unit and a vapor compression thermotransformer (VPTT) configured for simultaneously producing heat and cold, along with its operating principle, is described. The flow of transported gas (without combusting it) serves as the primary energy carrier supporting the plant operation. The gas flow energy is converted in mechanical work (as its pressure is decreased in the expander from the initial level at which gas arrives to the technological gas pressure reducing station to the level necessary according to the requirements of the gas utilization technology at the consumer end), and the generator connected to the expander converts this work into electricity. Part of the produced electricity is supplied to an external consumer, and its other part is used for driving the VPTT. The gas flow downstream of the expander supplied to the consumer and the flow of the VPTT working fluid, which takes heat from the cold carrier in the VPTT evaporator as it is transferred from a liquid to a gaseous state serve as the sources of cold in the plant. The working fluid downstream of the VPTT compressor serves as the source of heat; part of this is supplied to the consumer and its other part is used for heating gas upstream of the expander. The article presents the results from studying the effect the temperature to which gas upstream of the VPTT expander is heated by the heat of the VPTT working fluid has on the plant thermodynamic efficiency. The exergetic efficiency is taken as the thermodynamic efficiency criterion. The processes occurring in the plant when changing the gas heating temperature are subjected to a qualitative analysis. The results of calculations carried out using the plant mathematical model described in the article are presented. The obtained calculation results made it possible to determine the effect that the gas heating temperature upstream of the VPTT expander has on the specific (per unit flowrate of transported gas) electric, heating, and refrigeration capacities of the plant; on the specific exergy values of the same flows; and on the exergetic efficiency subject to the conditions adopted in the calculations.     

新型有机膨胀剂的研究

对腐植酸、木素磺酸钠、新型膨胀剂影响铅电极的电化学行为及极板放电性能进行了研究。循环伏安极化曲线表明不同有机膨胀剂对铅电极电化学行为影响规律相同；阴极极化曲线表明上述不同有机膨胀剂对析氢的影响差别可以忽略不计；首次放电性能试验与循环伏安结果一致。分析了腐植酸与木素相同与不同的作用机理。相同点在于影响铝电极电化学行为原理相同，不同点在于腐植酸主要通过吸附来防止负极收缩，而木素磺酸钠则主要通过造孔来防止负极收缩。     

关于负极膨胀剂及有机膨胀剂(三)--蓄电池充电电压的确定

免维护电池和阀控电池对充电电压很敏感,而添加负极膨胀剂又强烈影响电池的充电接受性能.论述了免维护电池和阀控密封电池对充电电压的要求,试验确定了采用不同负极有机膨胀剂、适用于汽车起动用富液免维护电池的适宜的充电电压.