近距電能傳輸——高效安全近距電能傳輸一般基于電磁感應原理進行。在此技術基礎上，當接收器鄰近發(fā)射器時才會進行電能傳輸。電磁感應技術的歷史長達百年，多年米一直應用于各類電子產品中—如此普及全因其簡單、高效以及安全技術概覽以下將為你簡要介紹無線電能傳輸技術。System Overview(Communication)Receiver sends messagesTo provide control information to the transmitterBy load modulation on the power signaTransmitter receives messagesTo receive control information frorn the recelverBy de-modulation of the reflected loadPower Pick Up( Receiver)Secondary coil (L Serial resonance capacitor (C) for efficient power transfer Parallel resonance capacitor(C, )for detection purposes Rectifier: full bridge(diode, or switched)+ capacitor Output switch for(dis)connecting the loadReceiver modulates load by Switching modulation resistor(R,n),or Switching modulation capacitor(Ca)Transmitter de-modulates reflected load by Sensing pnmary coil curent (p)and/o Sensing primary coil voltage (V,
在全球氣候變暖和石油資源短缺的形勢下,推動新能源汽車的發(fā)展將成為汽車行業(yè)一種新的發(fā)展方向。在大力發(fā)展新能源電動汽車行業(yè)的同時還應兼顧電動汽車充電設施的發(fā)展,因此對電動汽車充電樁的設計與研究顯得十分必要。對電動汽車直流充電樁的硬件系統(tǒng)進行設計,主要的硬件電路包括安全監(jiān)測電路、總壓采集電路、溫濕度檢測電路、語音電路。軟件包括主要流程圖和溫濕度檢測流程圖。Under the situation of global warming and shortage of petroleum resources,promoting the development of new energy vehicles will become a new development direction for the automotive industry.While vigorously developing the new energy electric vehicle industry,we should also take into account the development of electric vehicle charging facilities.Therefore,the design and research of electric vehicle charging piles is very necessary.The hardware system of the electric vehicle DC charging pile is designed.The main hardware circuits include safety monitoring circuit,total voltage collecting circuit,temperature and humidity detecting circuit,voice circuit and CAN communication.The software includes a main flow chart and a temperature and humidity detection flow chart.
電學中的測量技術涉及范圍非常廣,電流測量在電學計量中占有非常重要的位置。如何精確地進行電流測量是精密測量的一大難題。傳統(tǒng)的電流檢測電路多采用運算放大芯片與片外電流檢測電路相結合的方式,電路集成度很低,需要較多的接口和資源才能完成對電路的檢測。本文把所有電路部分都集成在一塊芯片上,包括檢測電阻,運算放大器電路及模擬轉數字轉換電路,從而在電路內部可以進行電流檢測,使電路更好的集成化。前置電路使用二級共源共柵結構的運算放大器,減小溝道長度調制效應造成的電流誤差。10位SAR ADC中采用電容驅動能力強的傳輸門保證了模數轉化器的有效精度。比較器模塊采用再生鎖存器與遲滯比較器作為基礎單元組合解決精密測量的問題。本設計可以作為嵌入芯片內的一小部分而檢測芯片中的微小電流1mA~100mA,工作電壓在1.8v左右,電流檢測精度預期達到10uA的需求。The measurement technology in electricity involves a wide range,and current measurement plays a very important position in electrical measurement.How to accurately measure current is a big problem in precision measurement. The traditional current detecting circuit adopts the combination of the operational amplifier chip and theoff-chip current detecting circuit, The circuit integration is very low, and more interfaces and resources are needed tocomplete the circuit detection.This topic integrates all the circuit parts into one chip, including detection resistance, operational amplifier circuit andanalog to digital conversion circuit. Highly integrated circuit makes the external resources on the chip more intensive,so that current detection can be carried out inside the circuit, so that the circuit can be better integrated. Thefront-end circuit of this project uses two-stage cascade operational amplifier and cascade tube to reduce the currenterror caused by channel length modulation effect. In 10-bit SAR ADC, the transmission gate with strong capacitivedriving ability ensures the effective accuracy of the analog-to-digital converter. Comparator module uses regenerativelatch and hysteresis comparator as basic unit to solve the difficult problem of precision measurement. This topic can beused as a small part of the embedded chip to detect the micro-current in the chip 1 mA~100 mA, the working voltageis about 1.8v, and the current detection accuracy is expected to reach the requirement of 10 uA.
超聲波換能器作為一種實用的檢測手段，能實現聲波所攜帶的信息和電能之間轉換。它的性能優(yōu)良，價格低廉，操作方便，易于調試，因此在工農業(yè)生產中發(fā)揮著重要的作用。但目前換能器驅動電路的發(fā)射頻率多為40 kHz，本文針對1 MHz的超聲波換能器電路進行了設計，主要介紹了它的發(fā)射驅動電路和接收驅動電路的設計方案，并對它們的功能進行了詳細地說明。最后搭建實驗平臺，并對電路的輸入、輸出模塊進行了測試。實驗結果表明，換能器電路運行良好，可以為超聲波高精度測量領域的應用提供參考。As a practical means of detection, ultrasonic transducer can realize the conversion between theinformation carried by sound wave and electric energy.It has the advantages of excellent performance,low cost, convenient operation and debugging, so plays an important role in industrial and agriculturalproduction.However, the transmitting frequency of the driving circuit for most transducer is 40 kHz.Thecircuit of 1 MHz ultrasonic transducer is designed In this paper. It mainly introduces the emissive drivingcircuit and the receiving circuit design and the detailed function of them. Finally, the experimentalplatform is built, and the circuit of input and output were tested. Experiments show that the transducer＇ s...
針對交流電路過零檢測電路存在結構復雜、過零點檢測不準確、編程繁瑣等問題，設計了一種基于LM339的硬件結構簡單的過零檢測電路。通過仿真軟件Mulisim對該設計電路進行了仿真，實驗證明了該方案過零檢測的可行性、穩(wěn)定性和可靠性，可直接作為交流電路中CPU的過零信號。Aiming at the problems of AC cilsuit zero crossing detection circuit such as complex structure, zero crossing detection and cumbersome programming, a zero crossing detection circuit with simple hardware structure based on LM339 was designed. The design circuit was simulated by simulation software Mulisim, and the feasibility, stability and reliability of zero crossing detection were proved by experiments, which can be used as zero crossing signal of CPU in AC circuit directly.
為了實時檢測血氧量,能使缺氧特別敏感的腦組織或心臟類疾病患者得到及時治療,采用近紅外雙波長透射式光電脈搏血氧測定法,以H橋電路對發(fā)射光源進行控制及通用運算放大器搭建濾波電路。運用參數理論計算和計算機仿真結果相對比的方法,通過Mu ltisim軟件對所設計電路進行仿真,仿真結果與理論參數計算相吻合,證明了電路參數設計的可行性,為血氧儀的實物制作提供參考。For real-time detection of oxygen saturation for timely treatment of the brain or heart,which are very sensitive to oxygen inadequacy,the near-infrared wavelengths double photoelectric pulse oximeter transmission method is adopted.The illuminant is controlled with the H bridge circuit and the filter circuit is built with general op-amps.Parameters by theoretical calculation is compared with the computer simulation results in Multisim and satisfactory results are obtained.It is shown that the design of the circuit parameters is feasible and can be a help in making the physical blood-oxygen monitor.
微弱信號檢測的目的是從噪聲中提取有用信號，或用一些新技術和新方法來提高檢測系統(tǒng)輸出信號的信噪比。本文簡要分析了常用的微弱信號檢測理論，對小波變換的微弱信號檢測原理進行了進一步的分析。然后提出了微弱信號檢測系統(tǒng)的軟硬件設計，在闡述了系統(tǒng)的整體設計的基礎上，對電路所選芯片的結構和性能進行了簡單的介紹，選用了具有14位分辨率的4路并行A/D轉換器AD7865作為模數轉換器，且選用Xilinx公司的Spartan-3系列FPGA邏輯器件作為控制器，控制整個系統(tǒng)的各功能模塊。同時，利用FPGA設計了先入先出存儲器，充分利用系統(tǒng)資源，降低了外圍電路的復雜度，為電路調試及制板帶來了極大的方便，且提升了系統(tǒng)的采集速度和集成度。系統(tǒng)的軟件設計采用Verilog HDL語言編程，在Xilinx ISE軟件開發(fā)平臺上完成編譯和綜合，并選用ModelSim SE 6.0完成了波形仿真。關鍵詞：微弱信號檢測；信號調理：FPGA：AD7865；Verilog HDL信息時代需要獲取許多有用的信息，多數科學研究及工程應用技術所需的信息都是通過檢測的方法來獲取的。若被檢測的信號非常微弱，就很容易被噪聲湮沒，那么很難有效的從噪聲中檢測出有用信號。微弱信號在絕對意義上是指信號本身非常微弱，而在相對意義上是指信號相對于強背景噪聲而言的非常微弱，也就是指信噪比極低。人們進行長期的研究工作來檢測被噪聲所覆蓋的微弱信號，分析噪聲產生的原因以及規(guī)律，且研究被測信號的特點、相關性以及噪聲統(tǒng)計特性，從而研究出從背景噪聲中檢測有用信號的方法。1微弱信號檢測（Weak Signal detection）技術2.3.41主要是提高信號的信噪比，從噪聲中檢測出有用的微弱信號。對于這些微弱的被測量（如：微振動、微流量、微壓力、微溫差、弱光、弱磁、小位移、小電容等），大多數都是利用相應的傳感器將微弱信號轉換為微弱電流或者低電壓，再經過放大器將其幅度放大到預期被測量的大小。
