As environmental concerns over traditional lighting increaseand the price of LEDs decreases, high power LEDsare fast becoming a popular lighting solution for offl ineapplications. In order to meet the requirements of offl inelighting—such as high power factor, high effi ciency, isolationand TRIAC dimmer compatibility—prior LED driversused many external discrete components, resulting incumbersome solutions. The LT®3799 solves complexity,space and performance problems by integrating all therequired functions for offl ine LED lighting.
上傳時(shí)間： 2013-10-13
上傳用戶：dongqiangqiang
The voltage range of Linear Technology’s PowerPath® circuitscan be easily extended with just a few components, thusallowing them to meet the needs of virtually all applications.This application note presents solutions for circuits thatmust withstand large negative voltages, a reverse adapterinput for example, and circuits that must withstand largepositive inputs, such as automotive load-dump.
標(biāo)簽： PowerPath 汽車 工業(yè)應(yīng)用 電路
上傳時(shí)間： 2013-10-21
上傳用戶：幾何公差
In a recent discussion with a system designer, the requirementfor his power supply was to regulate 1.5Vand deliver up to 40A of current to a load that consistedof four FPGAs. This is up to 60W of power that must bedelivered in a small area with the lowest height profi lepossible to allow a steady fl ow of air for cooling. Thepower supply had to be surface mountable and operateat high enough effi ciency to minimize heat dissipation.He also demanded the simplest possible solution so histime could be dedicated to the more complex tasks. Asidefrom precise electrical performance, this solution had toremovethe heat generated during DC to DC conversionquickly so that the circuit and the ICs in the vicinity do notoverheat. Such a solution requires an innovative designto meet these criteria:
標(biāo)簽： FPGA DCDC 集成 穩(wěn)壓器
上傳時(shí)間： 2013-11-24
上傳用戶：defghi010
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.
標(biāo)簽： 高效率 密度 多相轉(zhuǎn)換器 高電流
上傳時(shí)間： 2013-10-08
上傳用戶：zhqzal1014
針對(duì)煤礦井下調(diào)度及緊急救援系統(tǒng)的需求，以DTMF編解碼模塊為核心，設(shè)計(jì)了具有自動(dòng)撥號(hào)功能的新型電話系統(tǒng)。該系統(tǒng)利用MT8880對(duì)DTMF信號(hào)的編解碼功能實(shí)現(xiàn)一鍵撥號(hào)和遠(yuǎn)程設(shè)置，通過(guò)檢測(cè)振鈴和忙音信號(hào)，完成自動(dòng)摘機(jī)和掛機(jī)過(guò)程，配合AGC等外圍電路達(dá)到話音清晰流暢的效果。 Abstract: To meet the demand for mine scheduling and emergency rescue system， with using DTMF signal codec as the core， a new telephone system was designed with automatic dialing function. In the system， the DTMF signal encoding and decoding function of MT8880 was used to achieve one-touch dialing and remote setting. The circuit detects the ringing and busy signal， and then completes automatic off-hook and hangup. With AGC(Automatic Gain Control) and other peripheral circuits， the voice was regulated to a clear and smooth effect.
標(biāo)簽： 8880 MT 撥號(hào)電話 系統(tǒng)設(shè)計(jì)
上傳時(shí)間： 2014-11-18
上傳用戶：ly1994
針對(duì)目前使用的RS232接口數(shù)字化B超鍵盤存在PC主機(jī)啟動(dòng)時(shí)不能設(shè)置BIOS，提出一種PS2鍵盤的設(shè)計(jì)方法。基于W78E052D單片機(jī)，采用8通道串行A/D轉(zhuǎn)換器設(shè)計(jì)了8個(gè)TGC電位器信息采集電路，電位器位置信息以鍵盤掃描碼序列形式發(fā)送，正交編碼器信號(hào)通過(guò)XC9536XL轉(zhuǎn)換為單片機(jī)可接收的中斷信號(hào)，軟件接收到中斷信息后等效處理成按鍵。結(jié)果表明，在滿足開機(jī)可設(shè)置BIOS同時(shí)，又可實(shí)現(xiàn)超聲特有功能，不需要專門設(shè)計(jì)驅(qū)動(dòng)程序，接口簡(jiǎn)單，成本低。 Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot， this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller，designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter， potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU， software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot， ultrasound specific functionality can be achieved at the same time， it does not require specially designed driver，the interface is simple and low cost.
標(biāo)簽： 單片機(jī) B超 數(shù)字化 鍵盤設(shè)計(jì)
上傳時(shí)間： 2013-10-10
上傳用戶：asdfasdfd
在航電系統(tǒng)維護(hù)過(guò)程中，為解決定位故障的效率和降低維修成本等問(wèn)題，提出了基于ICD（Interface Control Document，接口控制文件）的1553B總線的信息監(jiān)控系統(tǒng)模型。該系統(tǒng)運(yùn)用數(shù)據(jù)采集卡對(duì)總線中傳輸?shù)男盘?hào)有無(wú)失真、偏差等電氣特性進(jìn)行檢測(cè)，并使用1553B通訊卡通過(guò)測(cè)控軟件LabWindows/CVI編程與ICD數(shù)據(jù)庫(kù)的動(dòng)態(tài)鏈接，實(shí)現(xiàn)總線信息的解析和故障的判斷。與傳統(tǒng)的維護(hù)過(guò)程相比，這種模型能夠從信號(hào)的電氣特性以及信息的解析等全方位的去檢測(cè)判斷故障的來(lái)源，并且能夠廣泛在其他1553B總線系統(tǒng)內(nèi)擴(kuò)展應(yīng)用。驗(yàn)證表明該監(jiān)控系統(tǒng)可以對(duì)總線信息進(jìn)行快速有效地監(jiān)測(cè)分析，能滿足應(yīng)用需求。 Abstract: In the process of avionics system maintenance， to solve the problems such as improving the efficiency of fast orientation to troubles and reducing maintenance cost， system of 1553B bus information monitor model based on ICD was proposed. The system observed whether the data which transmitted on the bus appear distortion and deviation by using data acquisition card. And using 1553B communication card programming of the measure software LabWindows/CVI and the dynamic linking of ICD database， message analysis and fault estimation could be realized. Compared with traditional maintenance， this model can all-dimensionally detect and analyze the source of faults from both electrical characteristics of the signal and message analysis， and it can be widely applied in the other 1553B system. Experiment shown that this monitor system can effectively detect and analyze the bus message and can meet the application requirements.
標(biāo)簽： 1553B 總線 信息監(jiān)控
上傳時(shí)間： 2013-11-23
上傳用戶：18752787361
單片機(jī)作為一種微型計(jì)算機(jī)，其內(nèi)部具有一定的存儲(chǔ)單元（8031除外），但由于其內(nèi)部存儲(chǔ)單元及端口有限，很多情況下難以滿足實(shí)際需求。為此介紹一種新的擴(kuò)展方法，將數(shù)據(jù)線與地址線合并使用，通過(guò)軟件控制的方法實(shí)現(xiàn)數(shù)據(jù)線與地址線功能的分時(shí)轉(zhuǎn)換，數(shù)據(jù)線不僅用于傳送數(shù)據(jù)信號(hào)，還可作為地址線、控制線，用于傳送地址信號(hào)和控制信號(hào)，從而實(shí)現(xiàn)單片機(jī)與存儲(chǔ)器件的有效連接。以單片機(jī)片外256KB數(shù)據(jù)存儲(chǔ)空間的擴(kuò)展為例，通過(guò)該擴(kuò)展方法，僅用10個(gè)I/O端口便可實(shí)現(xiàn)，與傳統(tǒng)的擴(kuò)展方法相比，可節(jié)約8個(gè)I/O端口。 Abstract: As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
標(biāo)簽： 單片機(jī) P0口 數(shù)據(jù)存儲(chǔ)器 擴(kuò)展
上傳時(shí)間： 2014-12-26
上傳用戶：adada
介紹一種基于C8051單片機(jī)的動(dòng)態(tài)心電監(jiān)護(hù)系統(tǒng)。該系統(tǒng)由兩部分組成：以C8051F320單片機(jī)為核心的數(shù)據(jù)采集裝置和以PC機(jī)為平臺(tái)的分析處理系統(tǒng)。硬件電路功耗低，由單片機(jī)自帶的USB接口將數(shù)據(jù)傳送給PC機(jī)。軟件平臺(tái)采用LabVIEW可視化虛擬儀器系統(tǒng)開發(fā)平臺(tái)，將傳統(tǒng)儀器的功能模塊集成到計(jì)算機(jī)中，用戶可通過(guò)修改虛擬儀器的程序改變其功能。采用USB接口實(shí)時(shí)傳輸心電數(shù)據(jù)，并將數(shù)據(jù)采集模塊設(shè)計(jì)為計(jì)算機(jī)外設(shè)，使該系統(tǒng)高速快捷、小巧便攜。 Abstract: In this design，a low-cost ECG electrocardiogram monitoring system is introduced，which consists of two parts:data acquisition device based on C8051F320and PC terminal as the analysis and processing system.The system is low-power consumption，the data is transmitted to the PC terminal by USB interface of the C8051F320.By using the visible virtual instrument system developing platform LabVIEW，the traditional instruments function modules are integrated into the computer，so the user can modify virtual instrument software to change its function to meet their needs.Using USB in-terface to realize real-time ECG data transmission，in addition，ECG data acquisition module is designed as the computer peripheral，which makes the syetem high-speed and portable.
標(biāo)簽： C8051F320 心電監(jiān)護(hù) 系統(tǒng)設(shè)計(jì)
上傳時(shí)間： 2013-11-13
上傳用戶：zhangzhenyu
介紹一種多功能音樂(lè)播放器，它是以AT89S52單片機(jī)為核心，并輔有一些外圍器件，采用匯編語(yǔ)言編寫程序，實(shí)現(xiàn)多功能音樂(lè)播放，歌曲自動(dòng)循環(huán)播放和使用琴鍵自編曲目功能。此外，彩燈顯示歌曲節(jié)奏，按鍵跳轉(zhuǎn)到喜愛(ài)曲目，液晶顯示當(dāng)前播英文曲目。并給出了系統(tǒng)軟硬件設(shè)計(jì)。 Abstract: It introduces a multifunctional music player,taking AT89S52 single-chip microcomputer as hardware control core and using some peripheral elements.Programmes are compiled in assembly language to act as expected.There are two functional modes in this system.One is to make the music play automatically and consecutively,the other is to compose new songs through keys.In addition,lights show the pace of music and the English names can be displayed in the liquid crystal screen.With perfect combination of hardware and software,the music player can meet many music lovers’needs for multifunctional music player.And the hardware and software of the system are given.
上傳時(shí)間： 2013-11-18
上傳用戶：xiaodu1124
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