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.
上传时间： 2013-11-23
上传用户：lu2767
摘要：本水位监测报警器使用5V低压直流电源（也可以用3节5号电池代替）就可以对5~15厘米的水位进行监测，用LED显示和数码管显示水位，并可以对不再此范围内的水位发出报警。主要采用CD4066、74LS86、74LS32、CD4511芯片，再加上数码管、蜂鸣器、发光二极管、电阻这些器件组成一个简单而灵敏的监测报警电路，操作简单，接通电源即可工作。因为大部分电路采用数字电路，所以本水位监测报警器还具有耗能低、准确性高的特点。关键字：译码电路 报警电路 监测电路 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
上传时间： 2013-11-05
上传用户：王庆才
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.
上传时间： 2013-11-25
上传用户：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.
上传时间： 2013-10-24
上传用户：s蓝莓汁
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
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是一个用PHP编写的搜索引擎，它使用MySQL数据库后台。它的功能有静态和动态页面索引，在HTML内容中用hrefs, areamaps，和frames以及全文本索引构成所有的链接网。搜索结果的外观是可定制外观的，使用一个非常简单的模板系统。
标签： database features indexing backend
上传时间： 2014-01-03
上传用户：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. :)
标签： mobile-phone possible project almost
上传时间： 2015-04-08
上传用户：xiaodu1124
嵌入式文件系统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.
标签： relative project should paths
上传时间： 2015-04-28
上传用户：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是一个多语言，宏编译器，可以在一个单独的文件中定义所有的语法和代码生成。Draak 是一个单独的二进制文件，可以在任意平台上只使用一个文件来编译任何上下文无关的语言（类似 C, Pascal, Java）。
标签： multi-language generation compiler defined
上传时间： 2013-12-30
上传用户：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.
标签： graspForth Forth-in-C following attempt
上传时间： 2015-05-23
上传用户：tfyt
