As the performance of many handheld devices approachesthat of laptop computers, design complexity also increases.Chief among them is thermal management—how doyou meet increasing performance demands while keepinga compact and small product cool in the user’s hand?For instance, as battery capacities inevitably increase,charge currents will also increase to maintain or improvetheir charge times. Traditional linear regulator-based batterychargers will not be able to meet the charge currentand effi ciency demands necessary to allow a product torun cool. What is needed is a switching-based chargerthat takes just about the same amount of space as a linearsolution—but without the heat.
上傳時(shí)間： 2013-11-23
上傳用戶：lu2767
摘要：本水位監(jiān)測(cè)報(bào)警器使用5V低壓直流電源（也可以用3節(jié)5號(hào)電池代替）就可以對(duì)5~15厘米的水位進(jìn)行監(jiān)測(cè)，用LED顯示和數(shù)碼管顯示水位，并可以對(duì)不再此范圍內(nèi)的水位發(fā)出報(bào)警。主要采用CD4066、74LS86、74LS32、CD4511芯片，再加上數(shù)碼管、蜂鳴器、發(fā)光二極管、電阻這些器件組成一個(gè)簡(jiǎn)單而靈敏的監(jiān)測(cè)報(bào)警電路，操作簡(jiǎn)單，接通電源即可工作。因?yàn)榇蟛糠蛛娐凡捎脭?shù)字電路，所以本水位監(jiān)測(cè)報(bào)警器還具有耗能低、準(zhǔn)確性高的特點(diǎn)。關(guān)鍵字：譯碼電路 報(bào)警電路 監(jiān)測(cè)電路 Abstract: The water level alarm monitoring the use of 5 V low-voltage DC power (can also use three batteries replaced on the 5th) will be able to 5 to 15 centimeters of water level monitoring, with LED display and digital display of water level, and this can no longer Within the scope of a water level alarm. Mainly CD4066, 74LS86, 74LS32, CD4511 chips, coupled with digital control, buzzer, light-emitting diode, the resistance of these devices composed of a simple and sensitive monitoring alarm circuits. Because the majority of circuits using digital circuitry, so the water level monitored alarm system also has low energy consumption, high accuracy of the characteristics. Keyword: Decoding circuit alarm circuit monitoring circuit
標(biāo)簽： 水位 監(jiān)測(cè)報(bào)警 系統(tǒng)原理
上傳時(shí)間： 2013-11-05
上傳用戶：王慶才
In today’s world of modular networking and telecommunications design, it is becomingincreasingly difficult to keep alignment with the many different and often changing interfaces,both inter-board and intra-board. Each manufacturer has their own spin on the way in whichdevices are connected. To satisfy the needs of our customers, we must be able to support alltheir interface requirements. For us to be able to make products for many customers, we mustadopt a modular approach to the design. This modularity is the one issue that drives the majorproblem of shifting our bits from one modular interface to another.
標(biāo)簽： 150 WP 兆兆 網(wǎng)絡(luò)
上傳時(shí)間： 2013-11-25
上傳用戶：suicone
The NCV7356 is a physical layer device for a single wire data linkcapable of operating with various Carrier Sense Multiple Accesswith Collision Resolution (CSMA/CR) protocols such as the BoschController Area Network (CAN) version 2.0. This serial data linknetwork is intended for use in applications where high data rate is notrequired and a lower data rate can achieve cost reductions in both thephysical media components and in the microprocessor and/ordedicated logic devices which use the network.The network shall be able to operate in either the normal data ratemode or a high-speed data download mode for assembly line andservice data transfer operations. The high-speed mode is onlyintended to be operational when the bus is attached to an off-boardservice node. This node shall provide temporary bus electrical loadswhich facilitate higher speed operation. Such temporary loads shouldbe removed when not performing download operations.The bit rate for normal communications is typically 33 kbit/s, forhigh-speed transmissions like described above a typical bit rate of83 kbit/s is recommended. The NCV7356 features undervoltagelockout, timeout for faulty blocked input signals, output blankingtime in case of bus ringing and a very low sleep mode current.
上傳時(shí)間： 2013-10-24
上傳用戶：s藍(lán)莓汁
在研究傳統(tǒng)家用燃?xì)鈭?bào)警器的基礎(chǔ)上，以ZigBee協(xié)議為平臺(tái)，構(gòu)建mesh網(wǎng)狀網(wǎng)絡(luò)實(shí)現(xiàn)網(wǎng)絡(luò)化的智能語(yǔ)音報(bào)警系統(tǒng)。由于傳感器本身的溫度和實(shí)際環(huán)境溫度的影響，傳感器標(biāo)定后采用軟件補(bǔ)償方法。為了減少系統(tǒng)費(fèi)用，前端節(jié)點(diǎn)采用半功能節(jié)點(diǎn)設(shè)備，路由器和協(xié)調(diào)器采用全功能節(jié)點(diǎn)設(shè)備，構(gòu)建mesh網(wǎng)絡(luò)所形成的家庭內(nèi)部報(bào)警系統(tǒng)，通過(guò)通用的電話接口連接到外部的公用電話網(wǎng)絡(luò)，啟動(dòng)語(yǔ)音模塊進(jìn)行報(bào)警。實(shí)驗(yàn)結(jié)果表明，在2.4 GHz頻率下傳輸，有墻等障礙物的情況下，節(jié)點(diǎn)的傳輸距離大約為35 m，能夠滿足家庭需要，且系統(tǒng)工作穩(wěn)定，但在功耗方面仍需進(jìn)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.
標(biāo)簽： ZigBee 無(wú)線智能 家 報(bào)警系統(tǒng)
上傳時(shí)間： 2013-10-30
上傳用戶：swaylong
PhpDig is a search engine written in PHP that uses a MySQL database backend. It features indexing of both static and dynamic pages, spidering of almost all links in HTML content, in hrefs, areamaps, and frames, and full text indexing. The search results appearence is skin-able, using a very simple templates system. PhpDig是一個(gè)用PHP編寫的搜索引擎，它使用MySQL數(shù)據(jù)庫(kù)后臺(tái)。它的功能有靜態(tài)和動(dòng)態(tài)頁(yè)面索引，在HTML內(nèi)容中用hrefs, areamaps，和frames以及全文本索引構(gòu)成所有的鏈接網(wǎng)。搜索結(jié)果的外觀是可定制外觀的，使用一個(gè)非常簡(jiǎn)單的模板系統(tǒng)。
標(biāo)簽： database features indexing backend
上傳時(shí)間： 2014-01-03
上傳用戶：haohaoxuexi
The goal with this project was to make it possible for almost any mobile-phone to use ICQ and be able to communicate with other users! One other goal with this project was to lower the GPRS-traffic in the phone and make the ICQ-ing cheaper. A third goal was to make this service as easy to log-in to as possible. Anyone tried to fill a log-in screen with a WAP-browser should know what I mean. With Wapmess all you have to do is to write your login-url ONCE and then bookmark it in your phone, to make it available fast. :)
標(biāo)簽： mobile-phone possible project almost
上傳時(shí)間： 2015-04-08
上傳用戶：xiaodu1124
嵌入式文件系統(tǒng)ucfs.zip This project should serve as an "easy start" with /FS. All paths are relative to the project file. You should therefore be able to copy the entire directory (including all subdirectories) to any location on your harddrive.
標(biāo)簽： relative project should paths
上傳時(shí)間： 2015-04-28
上傳用戶：zhliu007
Draak is a multi-language, macro compiler, meaning all syntax and code generation is defined in a single file. Draak is a single binary that is able to compile any context free language (like C, Pascal, Java) for any platform with only 1 file. Draak Compiler是一個(gè)多語(yǔ)言，宏編譯器，可以在一個(gè)單獨(dú)的文件中定義所有的語(yǔ)法和代碼生成。Draak 是一個(gè)單獨(dú)的二進(jìn)制文件，可以在任意平臺(tái)上只使用一個(gè)文件來(lái)編譯任何上下文無(wú)關(guān)的語(yǔ)言（類似 C, Pascal, Java）。
標(biāo)簽： multi-language generation compiler defined
上傳時(shí)間： 2013-12-30
上傳用戶：a673761058
graspForth is my humble attempt at a Forth-in-C that has the following goals: GCC ......... to support all 32-bit micros that GCC cross-compiles to. Relocatable . to be able to run in-place in either Flash or Ram. Fast ........ to be "not much" slower than an assembly based native Forth. Small ....... to fit-in approx 300 words in less than 25Kbytes on a 32-bit machine. Portable .... to achieve a 5 minute port to a new 32bit micro-processor, or micro-controller.
標(biāo)簽： graspForth Forth-in-C following attempt
上傳時(shí)間： 2015-05-23
上傳用戶：tfyt
蟲蟲下載站版權(quán)所有 京ICP備2021023401號(hào)-1
