Alkaline batteries are convenient because they’re easy tofi nd and relatively inexpensive, making them the powersource of choice for portable instruments and devicesused for outdoor recreation. Their long shelf life alsomakes them an excellent choice for emergency equipmentthat may see infrequent use but must be ready to go on amoment’s notice. It is important that the DC/DC convertersin portable devices operate over the widest possiblebattery voltage range to extend battery run time, and thussave the user from frequent battery replacement.
標(biāo)簽： 428 DN 同步升壓 轉(zhuǎn)換器
上傳時(shí)間： 2014-12-24
上傳用戶(hù)：569342831
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.
標(biāo)簽： 筆記本電腦 功率調(diào)節(jié)
上傳時(shí)間： 2013-11-11
上傳用戶(hù)：大三三
為了有效地提升鉛酸蓄電池的使用壽命，同時(shí)實(shí)現(xiàn)對(duì)充電過(guò)程的監(jiān)控，設(shè)計(jì)出一種用單片機(jī)控制的36 V鉛酸蓄電池充電電源。本電路采用反激式拓?fù)?，連續(xù)電流工作模式，電源管理IC設(shè)計(jì)在電源的副邊，由ELAN公司的EM78P258N單片機(jī)模擬，是用可編程器件模擬電源管理IC，實(shí)現(xiàn)智能電源低成本化的一次成功嘗試，通過(guò)對(duì)單片機(jī)的軟件設(shè)計(jì)實(shí)現(xiàn)了充電電源的狀態(tài)顯示、充電時(shí)間控制、報(bào)警、過(guò)溫保護(hù)、過(guò)壓保護(hù)、過(guò)流保護(hù)等功能。本充電器真正的實(shí)現(xiàn)了鉛酸蓄電池的三段式充電過(guò)程，其最高輸出功率可達(dá)90 W，效率約85%，成本不到20元，具有很高的市場(chǎng)競(jìng)爭(zhēng)力。 Abstract: In order to extend the life of lead-acid battery efficiently and supervise the charging process meanwhile， a 36V lead-acid battery charge powe supply controlled by microcontroller is designed. The charger is flyback switching power supply and works in CCM mode. A EM78P258N microcontroller made by ELAN microelectronics corporation is used as power management IC which is designed at the secondary circuit. The project is a successful attempt to low-cost intelligent power used microcontroller simulating power management IC. The charger also has the functions of the status reveal， charge time control， alarming， thermal protect， current limit and overvoltage protect by the software design. The circuit actually implements the three-step charge process， whose power is up to 90W and whose efficiency can get 85%. The net cost of this charger is less than 20 RMB， so that the charger is of powerful market competitiveness.
標(biāo)簽： 單片機(jī)控制 充電電源 鉛酸蓄電池
上傳時(shí)間： 2013-11-16
上傳用戶(hù)：cepsypeng
在汽車(chē)發(fā)動(dòng)機(jī)起動(dòng)時(shí)，若發(fā)動(dòng)機(jī)起動(dòng)后起動(dòng)機(jī)不能及時(shí)斷電，將會(huì)燒毀起動(dòng)機(jī)或損壞飛輪齒環(huán)；若變速器不在空檔位置起動(dòng)，則起動(dòng)機(jī)的瞬間動(dòng)力將使汽車(chē)位移，還可能引起交通事故和人身安全。為此介紹一種利用NXP P89LPC901單片機(jī)控制的汽車(chē)起動(dòng)保護(hù)控制器，通過(guò)檢測(cè)汽車(chē)起動(dòng)開(kāi)關(guān)、變速箱檔位、發(fā)動(dòng)機(jī)轉(zhuǎn)速，實(shí)現(xiàn)對(duì)汽車(chē)發(fā)動(dòng)機(jī)起動(dòng)過(guò)程檢測(cè)和保護(hù)。起動(dòng)保護(hù)控制器在發(fā)動(dòng)機(jī)起動(dòng)過(guò)程中通過(guò)采用逐個(gè)關(guān)閉打開(kāi)負(fù)載系統(tǒng)，解決汽車(chē)發(fā)動(dòng)機(jī)過(guò)程中因起動(dòng)電流大而對(duì)汽車(chē)電源的沖擊影響,延長(zhǎng)了電瓶壽命。 Abstract: When the automotive engine is started, the engine start motor and flywheel gear may be damaged， even traffic accidents and personal safeties may be caused by wrong operation or other factors.In order to ensure the automotive engine can be started normally and safely,it is necessary that the protecting measures and methods are considered in the automotive electrical control system.This paper introduces a kind of the automotive engine starting protect controller based on NXP P89LPC901 MCU.The controller can protect the engine starting process by detecting the starter key switch,transmission stall and engine speed.Through the use of close and open load system,the controller can solve the impact on automotive power because of the high-current load in the process of the automobile engine starting, and extend battery life.
上傳時(shí)間： 2013-10-15
上傳用戶(hù)：mikesering
Most designers wish to utilize as much of a device as possible in order to enhance the overallproduct performance, or extend a feature set. As a design grows, inevitably it will exceed thearchitectural limitations of the device. Exactly why a design does not fit can sometimes bedifficult to determine. Programmable logic devices can be configured in almost an infinitenumber of ways. The same design may fit when you use certain implementation switches, andfail to fit when using other switches. This application note attempts to clarify the CPLD softwareimplementation (CPLDFit) options, as well as discuss implementation tips in CoolRunnerTM-IIdesigns in order to maximize CPLD utilization.
上傳時(shí)間： 2014-01-11
上傳用戶(hù)：a471778
In this paper, we describe the development of a mobile butterfly-watching learning (BWL) system to realize outdoor independent learning for mobile learners. The mobile butterfly-watching learning system was designed in a wireless mobile ad-hoc learning environment. This is first result to provide a cognitive tool with supporting the independent learning by applying PDA with wireless communication technology to extend learning outside of the classroom. Independent learning consists of self-selection, self-determination, self-modification, and self-checking.
標(biāo)簽： butterfly-watching development describe learning
上傳時(shí)間： 2014-11-26
上傳用戶(hù)：waizhang
SQL Server 2005 Integration Services (SSIS) is a new Extract, Transform, and Load (ETL) tool that ships with SQL Server 2005. As with many of Microsoft s development tools, you can extend SSIS to perform other operations not already bundled with the product. SSIS provides the SSIS Class Library for just this purpose. The SSIS Class Library Object Model includes all the classes and interfaces you need to extend or augment SSIS.
標(biāo)簽： Integration Transform Services Extract
上傳時(shí)間： 2015-10-11
上傳用戶(hù)：baiom
A collection of command line tools which illustrate features of the file system. Demonstrates extended attributes, ACL s, and kqueue notification mechanisms.
標(biāo)簽： Demonstrates collection illustrate features
上傳時(shí)間： 2016-01-14
上傳用戶(hù)：yuanyuan123
This directory contains the Genetic Algorithm Optimization Toolbox for Matlab To use this, if you are local to NCSU and have AFS access to this directory, simply extend the matlab path using the following command. You can also place this command in a file called startup.m. Everytime you start Matlab in the directory containing this file, the path will always be extended.
標(biāo)簽： Optimization Algorithm directory contains
上傳時(shí)間： 2014-01-18
上傳用戶(hù)：songnanhua
A Java port of LDC s Champollion sentence aligner (http://champollion.sourceforge.net). Intended audience is Natural Language researchers wishing to sentence-align parallel text. In the future, Akerblad will extend Champollion with such features as rule
標(biāo)簽： Champollion champollion sourceforge Intended
上傳時(shí)間： 2016-03-19
上傳用戶(hù)：yzhl1988
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