Abstract: Some types of loads require more current during startup than when running. Other loads can be limited to a lower-powercurrent during startup but require a higher operating current. This article describes an application circuit that automatically adjusts apower circuit’s overcurrent protection level up or down after startup is complete.
標(biāo)簽： FET 保護(hù) 集成 電源開(kāi)關(guān)
上傳時(shí)間： 2013-10-23
上傳用戶：swaylong
Smart Batteries are an increasingly popular choice formore than just traditional compact consumer electronicdevices. For example, Smart Batteries are being used asbattery backup for products such as blade servers, whereknowing battery status is very important
標(biāo)簽： 智能電池 充電器 備用電池 服務(wù)器
上傳時(shí)間： 2013-11-02
上傳用戶：wangzhen1990
Avalanche photo diode (APD) receiver modules arewidely used in fi ber optic communication systems. AnAPD module contains the APD and a signal conditioningamplifi er, but is not completely self contained. It stillrequires signifi cant support circuitry including a highvoltage, low noise power supply and a precision currentmonitor to indicate the signal strength. The challenge issqueezing this support circuitry into applications withlimited board space. The LT®3482 addresses this challengeby integrating a monolithic DC/DC step-up converter andan accurate current monitor. The LT3482 can supportup to a 90V APD bias voltage, and the current monitorprovides better than 10% accuracy over four decades ofdynamic range (250nA to 2.5mA).
上傳時(shí)間： 2014-01-18
上傳用戶：wenyuoo
Once relegated to the hinterlands of low cost indicatorlights, the LED is again in the spotlight of the lightingworld. LED lighting is now ubiquitous, from car headlightsto USB-powered lava lamps. Car headlights exemplifyapplications that capitalize on the LED’s clear advantages—unwavering high quality light output, tough-assteelrobustness, inherent high effi ciency—while a USBlava lamp exemplifi es applications where only LEDs work.Despite these clear advantages, their requirement forregulated voltage and current make LED driver circuitsmore complex than the venerable light bulb, but some newdevices are closing the gap. For instance, the LTM®8040μModule™ LED driver integrates all the driver circuitryinto a single package, allowing designers to refocus theirtime and effort on the details of lighting design criticalto a product’s success.
上傳時(shí)間： 2013-10-16
上傳用戶：togetsomething
Specifying the right reference and applying it correctly isa more difficult task than one might first surmise, consideringthat references are only 2- or 3-terminal devices.Although the word “accuracy” is most often spoken inreference to references, it is dangerous to use this wordtoo freely because it can mean different things to differentpeople. Even more perplexing is the fact that a referenceclassified as a dog in one application is a panacea inanother. This application note will familiarize the readerwith the various aspects of reference “accuracy” andpresent some tips on extracting maximum performancefrom any reference.
標(biāo)簽： 電壓基準(zhǔn)
上傳時(shí)間： 2013-10-15
上傳用戶：liuwei6419
In August of 1992 LTC published Application Note 49, “Illumination Circuitry for Liquid Crystal Displays.” One notable aspect of this event is that it generated more response than all previous LTC application notes combined. This level of interest, along with significant performance advances since AN-49’s appearance, justifies further discussion of LCD backlighting circuitry.
上傳時(shí)間： 2013-11-19
上傳用戶：lanjisu111
為了提高傳統(tǒng)溫度控制系統(tǒng)的性能，將PID控制理論與嵌入式系統(tǒng)相結(jié)合，采用瑞薩電子公司的H8S/2166作為核心處理器，AD公司的AD7705以及熱敏電阻溫度傳感器作為溫度檢測(cè)單元，利用4×6小鍵盤(pán)、LCD顯示器和S1D13305液晶控制器達(dá)到良好的人機(jī)交互，設(shè)計(jì)出了一個(gè)應(yīng)用于化工領(lǐng)域的嵌入式實(shí)時(shí)溫度控制系統(tǒng)。相比于傳統(tǒng)溫度控制系統(tǒng)，該系統(tǒng)提供了更強(qiáng)的計(jì)算能力和可擴(kuò)展能力，采用增量PID控制算法實(shí)現(xiàn)復(fù)雜控制。通過(guò)實(shí)驗(yàn)，該系統(tǒng)能達(dá)到0.1 ℃的溫度控制精度以及小于120 s的溫度穩(wěn)定時(shí)間。 Abstract: In order to improve the performance of conventional temperature control system， combining PID control theory with embedded systems， using the Renesas Electronics Corp. H8S/2166 micro-controller as a core processors， AD7705 and thermistor temperature sensor as a temperature detection unit and 4×6 small keyboard， LCD and S1D13305 LCD controller as a good human-computer interaction， this paper designed an embedded real-time temperature control system which is applied in chemical industry. Compared with conventional temperature control system， this system provides more computing power and extensibility， and adopts PID control algorithm for complex control. Through the experiment， the system can reach temperature control accuracy of 0.1 ℃ and temperature stabilization time of less than 120 seconds.
標(biāo)簽： 瑞薩電子 微控制器 溫度控制 系統(tǒng)設(shè)計(jì)
上傳時(shí)間： 2014-12-26
上傳用戶：003030
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)洌B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：cepsypeng
生活中許多目標(biāo)的高度和水平距離需要進(jìn)行測(cè)量。目前主要的測(cè)量方法，仍以傳統(tǒng)的皮尺丈量為主，測(cè)量效率不高，有時(shí)還很不方便，沒(méi)有技術(shù)成熟的數(shù)字式測(cè)高測(cè)距產(chǎn)品。以基本的數(shù)學(xué)方法為理論依據(jù)，利用遙控小車(chē)做為載體，采用角度傳感器測(cè)量角度、霍爾傳感器測(cè)量水平距離等，通過(guò)單片機(jī)LM3S615進(jìn)行數(shù)據(jù)計(jì)算，實(shí)現(xiàn)了對(duì)待測(cè)目標(biāo)物體的高度、水平距離等數(shù)據(jù)的快速、精確和數(shù)字式的測(cè)量，高度測(cè)量精度可達(dá)99.06%，水平測(cè)量精度則可達(dá)98.06%。 Abstract: In our lives， the height and horizontal distance of some goals are needed to be measured. Because the currently used methods are still traditional tape-based measuring methods， and the measuring efficiency is low and inconvenient so some kinds of digital and portable measuring methods or instruments are needed. Based on the basic math theory， this paper designed and manufactured a portable， digital and remote controlled measuring mobile small vehicle， which assembled with angle measuring sensor for angle measurement and Hall sensor for horizontal distance measuring. MCU LM3S615 calculated the height and horizontal distance data gotten from these sensors. The measuring process is simple， the measuring results are more accurate and the measuring efficiency is higher than traditional measure instruments. The accuracy of height and distance measurement can reach 99.06% and 98.06%.
標(biāo)簽： ARM 單片機(jī) 自動(dòng)
上傳時(shí)間： 2013-10-30
上傳用戶：jackandlee
為解決輸油管道溫度壓力參數(shù)實(shí)時(shí)監(jiān)測(cè)的問(wèn)題，設(shè)計(jì)了以C8051F930單片機(jī)作為控制核心的超低功耗輸油管道溫度壓力遠(yuǎn)程監(jiān)測(cè)系統(tǒng)。現(xiàn)場(chǎng)儀表使用高精度電橋采集數(shù)據(jù)，通過(guò)433 MHz短距離無(wú)線通信網(wǎng)絡(luò)與遠(yuǎn)程終端RTU進(jìn)行通信，RTU通過(guò)GPRS網(wǎng)絡(luò)與PC上位機(jī)進(jìn)行遠(yuǎn)程數(shù)據(jù)傳輸，在上位機(jī)中實(shí)現(xiàn)數(shù)據(jù)存儲(chǔ)和圖形化界面顯示，從而實(shí)現(xiàn)輸油管道溫度壓力參數(shù)的實(shí)時(shí)監(jiān)測(cè)和異常報(bào)警。經(jīng)實(shí)驗(yàn)證明，該系統(tǒng)的12位數(shù)據(jù)采集精度滿足設(shè)計(jì)要求，漏碼率小于1%，正常工作時(shí)間超過(guò)5個(gè)月，能實(shí)時(shí)有效地監(jiān)測(cè)輸油管道的溫度壓力參數(shù)，節(jié)省大量人工成本，有效預(yù)防管道參數(shù)異常造成的經(jīng)濟(jì)損失和環(huán)境污染。 Abstract: In order to solve the problems on real-time monitoring of pipeline temperature and pressure parameters， the ultra-low power remote pipeline temperature and pressure monitoring system was designed by using the single chip processor C8051F930 as the control core. The high-precision electric bridge was used in field instruments for data collection， the 433MHz short-range wireless communication network was used to make communication between field instrument and RTU， the GPRS was used by the RTU to transmit data to the PC host computer， and the data was stored and displayed in the PC host computer， so the real-time monitoring and exception alerts of pipeline temperature and pressure parameters were achieved. The experiment proves that the system of which error rate is less than 1% over five months working with the 12-bit data acquisition accuracy can effectively monitor the pipeline temperature and pressure parameters in real time， it saves a lot of labor costs and effectively prevents environmental pollution and economic losses caused by abnormal channel parameters.
標(biāo)簽： C8051F930 溫度 壓力 遠(yuǎn)程監(jiān)測(cè)系統(tǒng)
上傳時(shí)間： 2013-11-07
上傳用戶：cuibaigao
蟲(chóng)蟲(chóng)下載站版權(quán)所有 京ICP備2021023401號(hào)-1
