DDS多波形信号发生器的设计与实现

详细介绍了直接数字频率合成器(DDS)的工作原理、基本结构.在参考大量DDS相关文献的基础上,提出了符合结构的DDS设计方案,利用DDS技术设计了一种高频率精度的多波形信号发生器,此设计基于可编程逻辑器件FPGA,采用Max+PlusⅡ开发平台,由Verilog_HDL编程实现.     

基于Lab VIEW的双通道信号发生器设计与实现

以虚拟仪器技术为核心,借助于计算机资源并结合高性能数据采集卡等硬件,采用Lab VIEW软件开发平台设计了一款双通道信号发生器.双通道信号发生器通过PCI-6289数据采集卡的D/A通道输出波形信号,可以产生正弦波、方波、三角波、锯齿波、白噪声信号与任意公式波,具有参数设置、功能选择、信号输出时域波形监测与参数存储等功能.实际运行表明,该信号发生器具有功能强大、频带范围宽、界面友好、使用更为方便等优点,避免了传统信号发生器只能产生基本波形的不足,具有良好的应用前景.     

基于FPGA的基带信号发生器的设计

采用基于DDS模块的硬件实现方法设计基带信号发生器,在FPGA内部用DDS模块进行频率合成和叠加,利用EDA技术和FPGA实现直接数字频率综合器DDS的设计.可以完成快速的频率切换,并且在改变时能够保持相位的连续,很容易实现频率、相位和幅度的数控调制.实验结果表明该信号发生器达到了一个比较好的设计精度.     

基于DDS和FPGA的多功能信号发生器设计

根据直接数字频率合成技术,以FPGA为核心,设计了一种便携式多功能信号发生器,可产生正弦波、方波、三角波、锯齿波等信号。通过仿真及硬件实验表明,该信号发生器具有信号频率误差小、分辨率高、体积小、质量轻等优点。     

基于FPGA的智能函数发生器的设计

介绍了一种基于FPGA的智能函数发生器的设计.采用EDA技术对此设计进行功能仿真和时序仿真,在EDA/SOPC系统开发平台上实现程序下载,同时在示波器上观察波形输出.结果表明采用该设计能够生成递增斜波、递减斜波、方波、三角波、正弦波及阶梯波等,并可以对频率进行调节,实现了信号发生器的功能.     

顺控法编程在交通灯控制中的应用研究

根据十字路口交通灯控制系统的要求,选用西门子CPU224可编程控制器作为十字路口交通灯系统的控制器,应用顺控法编程思想设计出控制系统的顺序功能图,利用顺控继电器指令把顺序功能图转换为梯形图程序,设计出系统的硬件.控制系统硬件结构简单,主要控制功能通过顺控编程方法来实现.具有可靠性高、易于维护和扩展的特点.整个系统在试验台上进行了验证和调试.系统运行良好,满足了控制要求.     

基于FPGA的基带信号发生器的设计

采用基于DDS模块的硬件实现方法设计基带信号发生器,在FPGA内部用DDS模块进行频率合成和叠加,利用EDA技术和FPGA实现直接数字频率综合器DDS的设计。可以完成快速的频率切换,并且在改变时能够保持相位的连续,很容易实现频率、相位和幅度的数控调制。实验结果表明该信号发生器达到了一个比较好的设计精度。     

一种高性价比的多路信号发生器设计

讨论了一种用相对简单的实现方式和较少的成本并且具有良好稳定度和精确度的常用波形实现方法.基于可控的MAX038信号发生芯片,讨论了一种智能信号发生器设计.该发生器用于产生频率和幅度均可调节的正弦波、方波和三角波信号,支持波形种类选择、频率调节、输出幅度调节等功能.     

基于虚拟仪器的函数信号发生器设计

探讨了虚拟仪器技术在高校实验教学中的应用前景,阐述了函数信号发生器的组建方法;结合硬件和PC机,利用LabVIEW软件开发环境,设计了一个基于虚拟仪器技术的多功能函数信号发生器;给出了函数信号发生器的前面板和框图程序设计、并给出了性能指标。实验结果表明基于虚拟仪器技术的多功能函数信号发生器完全可以满足高校实验室教学的需要。     

交通信号灯PLC控制

本文采用日本松下公司FPO系列C16T型PLC(可编程控制器),实现了交通信号灯的自动控制过程.具体完成了PLC硬件设计和软件编程,并通过系统调试,达到交通灯自动控制的目的.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.     

STORIES

正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse.     

巧妙引语(英文)

正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between     

Information for Authors

正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof.