The LTC®4099 high effi ciency USB power manager andLi-Ion/Polymer battery charger seamlessly managespower distribution from multiple sources in portableapplications. It is differentiated from other USB powermanagers by its bidirectional I2C port that allows the hostmicroprocessor to control and monitor all aspects of theUSB power management and battery charging processes.In addition, a programmable interrupt generation functionalerts the host microprocessor to changes in device statusand provides unprecedented control of power managementfunctions. This high degree of confi gurability allowspost-layout changes in operation, even changes in thefi eld, and it allows a single qualifi ed device to be usedin a variety of products, thus reducing design time andeasing inventory management.
Abstract: As electronic systems take over many of the mechanical functions in a car—ranging from engine timing to steering andbraking—there is a growing concern about fault tolerance. There should not be a single point of failure that would prevent a car fromat least "limping" off the road or making it to the nearest service station. Redundant systems, watchdog timers, and other controlcircuits are used to reroute signals and perform other functions that ensure that a vehicle can safely make it off the road when afailure occurs.
As logic systems get larger and more complex, theirsupply current requirements continue to rise. Systemsrequiring 100A are fairly common. A high current powersupply to meet such requirements usually requires parallelingseveral power regulators to alleviate the thermalstress on the individual power components. A powersupply designer is left with the choice of how to drive theseparalleled regulators: brute-force single-phase or smartPolyPhaseTM.
Notebook and palmtop systems need a multiplicity ofregulated voltages developed from a single battery. Smallsize, light weight, and high efficiency are mandatory forcompetitive solutions in this area. Small increases inefficiency extend battery life, making the final productmuch more usable with no increase in weight. Additionally,high efficiency minimizes the heat sinks needed onthe power regulating components, further reducing systemweight and size.
為了改變目前電網(wǎng)現(xiàn)場(chǎng)作業(yè)管理的變電巡檢、變電檢修試驗(yàn)、輸電線路巡檢檢修等管理系統(tǒng)各自獨(dú)立運(yùn)行，信息不能共享，功能、效率受限，建設(shè)和維護(hù)成本高的現(xiàn)狀，提出了采用B/S+C/S構(gòu)架模式，將各現(xiàn)場(chǎng)作業(yè)管理模塊和生產(chǎn)MIS（管理系統(tǒng)）集成為一體的現(xiàn)場(chǎng)作業(yè)管理系統(tǒng)的設(shè)計(jì)方案，做到各子系統(tǒng)和生產(chǎn)MIS軟硬資源共享，做到同一數(shù)據(jù)唯一入口、一處錄入多處使用。各子系統(tǒng)設(shè)備人員等基礎(chǔ)信息來(lái)源于生產(chǎn)管理系統(tǒng)，各子系統(tǒng)又是生產(chǎn)管理系統(tǒng)的作業(yè)數(shù)據(jù)、缺陷信息的重要來(lái)源。經(jīng)過研究試用成功和推廣應(yīng)用，目前該系統(tǒng)已在江西電網(wǎng)220 kV及以上變電站全面應(yīng)用。
Abstract:
In order to improve the status that the substation field inspection system， substation equipments maintenance and testing system， power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency， and their construction and maintenance costs are high. This paper introduces a field standardized work management system based on B/S+C/S mode， integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS，the field work data of the sub systems are the source information of MIS， by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing， this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
When a system designer specifies a nonisolated dc/dc powermodule, considering the needed input voltage range isequally as important as considering the required performanceattributes and features. Generally, nonisolated moduleshave either a narrow or a wide input voltage range. Narrowinputmodules typically have a nominal input voltage of3.3, 5, or 12 V. For systems that operate from a tightlyregulated input bus—such as those that do not use batterybackup—a narrow-input module is often adequate sincethe input remains fairly stable.Offering greater flexibility, wide-input modules operatewithin a range of 7 to 36 V, which includes the popular12- or 24-V industrial bus. This enables a single module tobe used for generating multiple voltages. These modulesare ideal for industrial controls, HVAC systems, vehicles,medical instrumentation, and other applications that usea loosely regulated distribution bus. In addition, systemspowered by a rectifier/battery charger with lead-acidbattery backup almost always require wide-input modules.System designers who choose power supplies may wantto take a close look at the latest generation of wide-inputdc/dc modules.
Features: High efficiency, high reliability, low cost AC input range selected by switch 100% full load burn-in test Protections: Short circuit / Over load Fixed switching frequency at 25KHz Cooling by free air convection 1 year warranty Dimensions: 199*98*38mm (L*W*H)
The P89LPC912/913/914 are single-chip microcontrollers in low-cost 14-pin packages, based on a high performance processor architecture that executes instructions in two to four clocks, six times the rate of standard 80C51 devices. Many system level functions have been incorporated into the P89LPC912/913/914 in order to reduce component count, board space, and system cost.
為提高溫度測(cè)量效率，降低系統(tǒng)的成本，擴(kuò)展傳輸距離，設(shè)計(jì)出一種新型溫度采集系統(tǒng)。單片機(jī)通過控制具有單總線方式的溫度傳感器DS18B20實(shí)現(xiàn)對(duì)溫度的測(cè)量，同時(shí)單片機(jī)通過控制具有單總線方式300～450MHz頻率范圍內(nèi)的MAX7044與MAX7033無(wú)線發(fā)射與接收芯片實(shí)現(xiàn)溫度數(shù)據(jù)的無(wú)線傳輸。與傳統(tǒng)溫度采集系統(tǒng)相比，該系統(tǒng)利用單總線方式連接，采用無(wú)線傳輸方式實(shí)現(xiàn)遠(yuǎn)距離通信，易于系統(tǒng)的集成與擴(kuò)展。實(shí)驗(yàn)結(jié)果表明，該系統(tǒng)結(jié)構(gòu)簡(jiǎn)單、方便移植，能夠同時(shí)實(shí)現(xiàn)多達(dá)上百點(diǎn)溫度的測(cè)量與500m范圍的傳輸。
Abstract:
To improve the temperature measurement efficiency and reduce system cost,expansion of transmission distance,a new type of temperature acquisition system is designed.Microcontroller controlled temperature sensor DS18B20which has a single-bus achieves temperature measurement,while microcontroller by controlled the MAX7044and MAX7033chip with a single-bus and having300~450MHz radiofrequency to achieve the wireless transmission of temperature data.Compared with conventional temperature acquisition system,the system uses single-bus connected,and uses wireless transmission means to achieve long-distance communications,easy-to-system integration and expansion.The experimental results show that the system is simple,convenient transplantation,and can be implemented in as many as a hundred-point temperature measure-ment and the transmission range of500meters.
設(shè)計(jì)一種基于AT89C52的語(yǔ)音錄放系統(tǒng)，利用單片機(jī)、ISD2560語(yǔ)音錄放器件、麥克風(fēng)、揚(yáng)聲器等元器件實(shí)現(xiàn)硬件電路的設(shè)計(jì)，并利用C51高級(jí)語(yǔ)言設(shè)計(jì)ISD2560器件控制字的寫入和定時(shí)中斷程序。經(jīng)軟硬件調(diào)試，結(jié)果表明該系統(tǒng)錄放效果良好，具有一定的工程實(shí)用價(jià)值。
Abstract:
Voice recording and playback system based on AT89C52is designed in this paper.Using the single-chip microcomputer，voice recording and playback chip ISD2560，microphone and speaker to realize the hardware circuit design.Writing ISD2560control words and timing interrupt procedures are designed by C51advanced language.Through the hardware and software test,voice recording and playback system play better voice,and this system has some engineering practical values.
