为满足矿井安全生产要求,介绍了一种以AT89C51单片机为主控器,对环境空气的温度、有毒易燃气体的浓度等进行检测的监控系统。该系统配合外围电路能实现对上述环境指标的控制并存储相关数据与上位PC机通信。它采用硬件抗干扰和软件抗干扰技术,以确保整个系统工作的准确性。 Abstract: In order to meet the needs of mine produce safety,a kind of intellignet mine ambient monotoring and control system based on AT89C51 is introduced.This system can detect the temperature of ambient of mine,the density of poisonous inflammable gas,combined external circuit.With its function part, this system can change above-mentioned elements.
上传时间: 2013-11-10
上传用户:wendy15
介绍了基于单片机航空交流电参数测试仪的系统设计。以Silicon Labs公司的C8051F005单片机为核心设计出数据采集板,通过RS-232串口与上位机通讯。运用Lab Windows/CVI编写的上位机软件实现信号的检测以及波形和数据的显示,给出了测试仪硬件电路的组成和软件流程图。本系统具有硬件结构简单、容易实现和成本低等特点,在实际应用中其稳定性、精确性均能满足客户要求。 Abstract: The design of aeronautics AC parameters tester based on the single-chip is introduced.The core component of data acquisition board is C8051F005 single chip of Silicon Labs Company,and communication with PC through RS-232. The signal processing software programmed with LabWindows/CVI can be used successfully to fulfill inspection of signal and display of the waveform and data. The hardware and software configuration of test instrument are provided.The hardware of the system is simple, and can be easily realized.The stability and precision of the measurement instrument are enough to meet the requirements.
上传时间: 2013-11-18
上传用户:wang5829
介绍了电力操作电源与智能电池巡检系统的特点,给出了一种基于超低功耗单片机MSP430 F149针对中小型变电站自动化运行的专用设备的基本设计原理及实现方法,最后给出了详细硬件构成和软件实现。该系统能满足中小型变电站安全、可靠、自动运行的要求,并通过与上位机的串行通信实现变电站的远程管理和控制。 Abstract: The characters of the intelligent battery data logging system of the electric operation power are introduced.The basic design principle and the implemented methods of the special equipment which only designed for the middle or small transformer substation based on MSP430F149 are prescribed. Finally, the hardware block diagram and the software flow chart are also given. The function that the system finally needs to realize can basically meet with the middle or small transformer substation’s satisfy, reliably,and automatic running.And it can also realize the transformer substation long-distance management and control by serial communicating with the host computer.
上传时间: 2013-11-25
上传用户:黄华强
将现行的供暖计费方式由按建筑面积计费变为按消耗的热能计费是供暖计费方式发展趋势,为了满足这一计费方式变化的需要,设计了基于IC卡的预付费式新型供暖计费系统,通过测量用户采暖系统进出口的温度和流量,计算用户消耗的热能,利用IC卡记录用户预付费的金额和当年热能的单价,根据热能消耗和当年热能的单价计算用户采暖费,根据实际发生的供暖费用和预付费金额控制供暖的开停,这一计费方式的变化使供暖计费更趋合理。 Abstract: It is trend that the mode of heat charging is changed from billing by building area to by thermal energy. In order to meet the needs of heat charging mode changing, a new system of heat charging based on IC card is proposed. The user?蒺s energy consumption is calculated by measuring the user inlet and outlet temperature and flow,using the IC card to record the prepaid amount and the current price of heat. The user?蒺s heating costs is calculated according to energy consumption and current price, according to actual heating costs and prepaid amount,the system controls the heating opening or stopping. It is more reasonable that calculated heating costs by user heat consumption
上传时间: 2013-10-14
上传用户:大融融rr
Abstract: This application note explains the hardware of different types of 1-Wire® interfaces and software examples adapted to this hardware with a focus on serial ports. Depending on the types of iButtons required for a project and the type of computer to be used, the most economical interface is easily found. The hardware examples shown are basically two different types: 5V general interface and 12V RS-232 interface. Within the 5V group a common printed circuit board could be used for all circuits described. The variations can be achieved by different populations of components. The same principal is used for the 12V RS-232 interface. The population determines if it is a Read all or a Read/Write all type of interface. There are other possible circuit implementations to create a 1-Wire interface. The circuits described in this application note cover many different configurations. For a custom application, one of the described options can be adapted to meet individual needs.
标签: iButtons Reading Writing and
上传时间: 2013-10-29
上传用户:long14578
基于变频调速的水平连铸机拉坯辊速度控制系统Frequency Inverter Based Drawing RollerS peedC ontrolSy stem ofHorizontal Continuous Casting MachineA 伟刘冲旅巴(南 华 大 学电气工程学院,衡阳421001)摘要拉坯辊速度控制是水平连铸工艺的关键技术之一,采用变频器实现水平连铸机拉坯辊速度程序控制,由信号发生装置给变频器提供程控信号。现场应用表明该控制系统速度响应快,控制精度高,满足了水平连铸生产的需要。关键词水平连铸拉坯辊速度程序控制变频器Absh'act Speedc ontorlof dr awingor leris on eo fth ek eyte chnologiesfo rho rizontalco ntinuousca stingm achine.Fo rth ispu rpose,fr equencyco nverterisad optedfo rdr awingor lersp eedp rogrammablec ontorlof ho rizontalco ntinuousca stingm achine,th ep rogrammableco ntorlsi gnalto fr equencyc onverteris provided场a signal generator. The results of application show that the response of system is rapid and the control accuracy is high enough to meet thedemand of production of horizontal continuous casting.Keywords Horizontalco ntinuousc asting Drawingor ler Speedp rogrammablec ontrol Ferquencyin verter 随着 现 代 化工业生产对钢材需求量的日益增加,连铸生产能力已经成为衡量一个国家冶金工业发展水平的重要指标之一。近十几年来,水平连铸由于具有投资少、铸坯直、见效快等多方面的优点,国内许多钢铁企业利用水平连铸机来浇铸特种合金钢,发挥了其独特的优势并取得了较好的经济效益〔1,2)0采用 水 平 连铸机浇铸特种合金钢时,由于拉坯机是水平连铸系统中的关键设备之一,拉坯机及其控制性能的好坏直接影响着连铸坯的质量,因此,连铸的拉坯技术便成为整个水平连铸技术的核心。由于钢的冶炼过程是在高温下进行的,钢水温度的变化又容易影响铸坯的质量和成材率,因此,如何能在高温环境下控制好与铸坯速度相关的参数(拉、推程量,中停时间和拉坯频率等)对于确保连铸作业的进一步高效化,延长系统的连续作业时间十分关键。因此,拉坯辊速度控制技术是连铸生产过程控制领域中的关键技术之- [31
上传时间: 2013-10-12
上传用户:gxy670166755
Introduction to Xilinx Packaging Electronic packages are interconnectable housings for semiconductor devices. The major functions of the electronic packages are to provide electrical interconnections between the IC and the board and to efficiently remove heat generated by the device. Feature sizes are constantly shrinking, resulting in increased number of transistors being packed into the device. Today's submicron technology is also enabling large-scale functional integration and system-on-a-chip solutions. In order to keep pace with these new advancements in silicon technologies, semiconductor packages have also evolved to provide improved device functionality and performance. Feature size at the device level is driving package feature sizes down to the design rules of the early transistors. To meet these demands, electronic packages must be flexible to address high pin counts, reduced pitch and form factor requirements. At the same time,packages must be reliable and cost effective.
上传时间: 2013-10-22
上传用户:ztj182002
Abstract: High-performance base-station (BTS) receivers must meet half-IF spurious requirements, whichcan be achieved by using the proper RF mixer. To help engineers, this application note illustrates the
上传时间: 2013-10-17
上传用户:daoxiang126
在研究传统家用燃气报警器的基础上,以ZigBee协议为平台,构建mesh网状网络实现网络化的智能语音报警系统。由于传感器本身的温度和实际环境温度的影响,传感器标定后采用软件补偿方法。为了减少系统费用,前端节点采用半功能节点设备,路由器和协调器采用全功能节点设备,构建mesh网络所形成的家庭内部报警系统,通过通用的电话接口连接到外部的公用电话网络,启动语音模块进行报警。实验结果表明,在2.4 GHz频率下传输,有墙等障碍物的情况下,节点的传输距离大约为35 m,能够满足家庭需要,且系统工作稳定,但在功耗方面仍需进一步改善。 Abstract: On the basis of studying traditional household gas alarm system, this paper proposed the platform for the ZigBee protocol,and constructed mesh network to achieve network-based intelligent voice alarm system. Because of the sensor temperature and the actual environment temperature, this system design used software compensation after calibrating sensor. In order to reduce system cost, semi-functional node devices were used as front-end node, however, full-function devices were used as routers and coordinator,constructed alarm system within the family by building mesh network,connected to the external public telephone network through the common telephone interface, started the voice alarm module. The results indicate that nodes transmit about 35m in the distance in case of walls and other obstacles by 2.4GHz frequency transmission, this is able to meet family needs and work steadily, but still needs further improvement in power consumption.
上传时间: 2013-10-30
上传用户:swaylong
为了能够满足基站易于选址、优质快速的建站要求和易维护、低成本、高可靠的运行要求,本文对以方舱来实现一体化结构基站做出一番探讨。从系统设计的观点阐述了移动通信高性能基站天线设计的几个关键问题,介绍了智能天线技术在基站中的应用,并且用HFSS软件仿真了一种新型的对称阵子天线,该天线驻波比小于2的带宽可以达到60%,具有良好的宽频带特性。 Abstract: In order to meet the station construction requirement of easy site selection and fast base station, and meet the operational requirement of easy maintenance, low cost and high reliability, this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design, the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS, the VSWR of the antenna is less than 2, and the bandwidth was reach to 60%. So it has good broadband properties.
上传时间: 2013-11-20
上传用户:linlin