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分析了調(diào)幅信號和載波信號之間的相位差與調(diào)制信號的極性的對應關系,得出了相敏檢波電路輸出電壓的極性與調(diào)制信號的極性有對應關系的結(jié)論。為了驗證相敏檢波電路的這一特性,給出3 個電路方案,分別選用理想元件和實際元件,采用Multisim 對其進行仿真實驗,直觀形象地演示了相敏檢波電路的鑒相特性,是傳統(tǒng)的實際操作實驗所不可比擬的。關鍵詞:相敏檢波;鑒相特性;Multisim;電路仿真 Abstract : The corresponding relation between modulation signal polarity and difference phases of amplitudemodulated signal and the carrier signal ,the polarity of phase2sensitive detecting circuit output voltage and the polarity of modulation signal are correspondent . In order to verify this characteristic ,three elect ric circuit s plans are produced ,idea element s and actual element s are selected respectively. Using Multisim to carry on a simulation experiment ,and then demonst rating the phase detecting characteristic of the phase sensitive circuit vividly and directly. Which is t raditional practical experience cannot be com pared.Keywords :phase sensitive detection ;phase2detecting characteristic ;Multisim;circuit simulation
上傳時間： 2013-11-23
上傳用戶：guanhuihong
Abstract: The rapid build out of today's smart grid raises a number of security questions. In this article,we review two recent well-documented security breaches and a report of a security gap. These situationsinclude a 2009 smart-meter hack in Puerto Rico; a 2012 password discovery in grid distributionequipment; and insecure storage of a private key in distribution automation equipment. For each of theseattacks, we examine the breach, the potential threat, and secure silicon methods that, as part of acomplete security strategy, can help thwart the attacks.
標簽： 智能電網(wǎng) 安全性
上傳時間： 2013-10-27
上傳用戶：tecman
Abstract: The DS1875 features a pulse-width modulation (PWM) controller that can be used to control aDC-DC converter. The DC-DC converter can then be used to generate the high bias voltages necessaryfor avalanche photodiodes (APDs). This application note describes the operation of a boost converterthat uses the DS1875. Discussion covers the selection of the inductor and switching frequency, and theselection of components that improve the efficiency of the converter. Test data are presented.
標簽： DC-DC 如何設計 高效率 轉(zhuǎn)換器
上傳時間： 2013-10-26
上傳用戶：lyson
Abstract: The "vampire" drain on electricity by household gadgets is only one indicator of the lack of policies to conserve energy and protect people and businesses from a major energy disaster. Most
上傳時間： 2013-11-18
上傳用戶：wgh_kf
基于單片機的步進電機開環(huán)控制系統(tǒng):通過ATMEL89C51單片機對步進電機進行控制,主要介紹了步進電機控制器、驅(qū)動電路和LED顯示電路的設計,實現(xiàn)了步進電機的開環(huán)控制。在步進電機控制器的設計中,重點闡述了脈沖產(chǎn)生電路以及對速度的控制。該系統(tǒng)具有成本低、控制方便的特點。關鍵詞: 單片機; 步進電機; 開環(huán)控制 Abstract: The design using ATMEL89C51 single chip to control the step2motor with its controller, driving circuit and LED disp lay circuit to realize step motor open2loop controlwere introduced. For the controller in this design,the circuit to p roduce pulse and the speed controlwere expatiated emphatically. This system possesses features of lower cost, easier control.Key words: single ch ip; step2motor; open2loop con trol
標簽： 單片機 步進電機 開環(huán) 控制系統(tǒng)
上傳時間： 2013-10-13
上傳用戶：cicizoe
基于單片機的除塵控制器的設計:介紹通用控制儀的硬件組成和軟件設計,闡述了系統(tǒng)的性能指標和功能特點。該產(chǎn)品功能完善,可靠性高,具有很好的應用前景。關鍵詞: 除塵器;通用控制儀;單片機;系統(tǒng)設計 Abstract: The hardware structure and the software design are introduced in this paper, and the performance index and the features of the system are expounded. It has comp rehensive functions, high reliability and good app lication.Key words: dust catcher; universal controller; microcontroller; system design
上傳時間： 2013-11-16
上傳用戶：ming52900
摘要：本水位監(jiān)測報警器使用5V低壓直流電源（也可以用3節(jié)5號電池代替）就可以對5~15厘米的水位進行監(jiān)測，用LED顯示和數(shù)碼管顯示水位，并可以對不再此范圍內(nèi)的水位發(fā)出報警。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簡單而靈敏的監(jiān)測報警電路，操作簡單，接通電源即可工作。因為大部分電路采用數(shù)字電路，所以本水位監(jiān)測報警器還具有耗能低、準確性高的特點。關鍵字：譯碼電路 報警電路 監(jiān)測電路 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
標簽： 水位 監(jiān)測報警 系統(tǒng)原理
上傳時間： 2013-11-05
上傳用戶：王慶才
Abstract: The application note addresses how G3-PLC, a powerline communications protocol approvedby the International Telecommunications Union (ITU), enables mesh networking in advanced metering
標簽： 網(wǎng)狀網(wǎng)絡 應用筆記 通信
上傳時間： 2013-11-17
上傳用戶：erkuizhang
Abstract: The number of uses for microelectromechanical systems (MEMS) is growing—they allow us todo jobs once considered impossible. This tutorial explains the applications for MEMS and the increasingneed to provide precision control and drivers for these devices. Design and manufacturing considerationsare also discussed.
標簽： MEMS 微機電系統(tǒng) 控制驅(qū)動
上傳時間： 2013-11-12
上傳用戶：paladin
Abstract: The 1-Wire product family includes numerous devices that can be easily evaluated using a Windows®-based
上傳時間： 2013-10-12
上傳用戶：fudong911
