With more than two billion terminals in commercial operation world-wide, wire- less and mobile technologies have enabled a first wave of pervasive communication systems and applications. Still, this is only the beginning as wireless technologies such as RFID are currently contemplated with a deployment potential of tens of billions of tags and a virtually unlimited application potential. A recent ITU report depicts a scenario of “Internet of things” — a world in which billions of objects will report their location, identity, and history over wireless connections.
标签： Internet Things From The RFI of
上传时间： 2020-06-08
上传用户：shancjb
Multisim官方示例Multisim仿真例程基础电路范例135例合集:Chapter 1 - RLC CircuitsChapter 2 - DiodesChapter 3 - TransistorsChapter 4 - AmplifiersChapter 5 - OpampsChapter 6 - FiltersChapter 7 - Miscellaneous CircuitsFundamental Circuits.pdf004 Parallel DC Circuits.ms10005 Series-Parrallel DC Circuit.ms10006 Current Analysis.ms10007 Millmans Theorem 1.ms10008 Millmans Theorem 2.ms10009 Kirchhoff's Current Law.ms10010 Thevenin's Theorem.ms10011 Superposition Principle.ms10012 Nortons Theorem and Source Conversion.ms10013 AC Voltage Measurement.ms10014 Frequency Response of the Series RL Network.ms10015 RL High and Low Pass Filter.ms10016 Frequency Response of the Series RC Network.ms10017 RC High and Low Pass Filter.ms10019 Center-Tapped Full-Wave Rectifier.ms10020 Bridge Rectifier.ms10021 Capacitor-Input Rectifier Filter.ms10022 Diode Clipper (Limiter).ms10023 Diode Clipper.ms10024 Diode Clamper (DC Restorer).ms10025 Diode Voltage Doubler.ms10026 Zener Diode and Voltage Regulation 1.ms10027 Zener Diode and Voltage Regulation 2.ms10028 Zener Diode and Voltage Regulation 3.ms10105 TTL Inverter.ms10107 TTL Gate.ms10109 OR Gate Circuit.ms10111 Over-Damp Circuit.ms10113 Critical-Damp Circuit.ms10115 Series RLC Circuit 1.ms10117 Clapp Oscillator.ms10119 Differential Amplifier 1.ms10121 Differential Amplifier in Common Mode.ms10123 LC Oscillator with Unity Gain Buffer.ms10125 Notch Filter.ms10127 PNP Differential Pair.ms10129 Crossover Network.ms10131 Second-Order High-Pass Chebyshev Filter.ms10133 Third-Order High-Pass Chebyshev Filter.ms10135 Fifth-Order High-Pass Filter.ms10
标签： multisim
上传时间： 2021-10-27
上传用户：trh505
基于TMS320F2812 光伏并网发电模拟装置PROTEL设计原理图+PCB+软件源码+WORD论文文档,硬件采用2层板设计，PROTEL99SE 设计的工程文件，包括完整的原理图和PCB文件，可以做为你的学习设计参考。 摘要：本文实现了一个基于TMS320F2812 DSP芯片的光伏并网发电模拟装置，采用直流稳压源和滑动变阻器来模拟光伏电池。通过TMS320F2812 DSP芯片ADC模块实时采样模拟电网电压的正弦参考信号、光伏电池输出电压、负载电压电流反馈信号等。经过数据处理后，用PWM模块产生实时的SPWM 波，控制MOSFET逆变全桥输出正弦波。本文用PI控制算法实现了输出信号对给定模拟电网电压的正弦参考信号的频率和相位跟踪，用恒定电压法实现了光伏电池最大功率点跟踪（MPPT），从而达到模拟并网的效果。另外本装置还实现了光伏电池输出欠压、负载过流保护功能以及光伏电池输出欠压、过流保护自恢复功能、声光报警功能、孤岛效应的检测、保护与自恢复功能。系统测试结果表明本设计完全满定设计要求。关键词：光伏并网，MPPT，DSP Photovoltaic Grid-connected generation simulator Zhangyuxin，Tantiancheng，Xiewuyang(College of Electrical Engineering, Chongqing University)Abstract: This paper presents a photovoltaic grid-connected generation simulator which is based on TMS320F2812 DSP, with a DC voltage source and a variable resistor to simulate the characteristic of photovoltaic cells. We use the internal AD converter to real-time sampling the referenced grid voltage signal, outputting voltage of photovoltaic, feedback outputting voltage and current signal. The PWM module generates SVPWM according to the calculation of the real-time sampling data, to control the full MOSFET inverter bridge output sine wave. We realized that the output voltage of the simulator can track the frequency and phase of the referenced grid voltage with PI regulation, and the maximum photovoltaic power tracking with constant voltage regulation, thereby achieved the purpose of grid-connected simulation. Additionally, this device has the over-voltage and over-current protection, audible and visual alarm, islanding detecting and protection, and it can recover automatically. The testing shows that our design is feasible.Keywords: Photovoltaic Grid-connected，MPPT，DSP 目录引言 11. 方案论证 11.1. 总体介绍 11.2. 光伏电池模拟装置 11.3. DC-AC逆变桥 11.4. MOSFET驱动电路方案 21.5. 逆变电路的变频控制方案 22. 理论分析与计算 22.1. SPWM产生 22.1.1. 规则采样法 22.1.2. SPWM 脉冲的计算公式 32.1.3. SPWM 脉冲计算公式中的参数计算 32.1.4. TMS320F2812 DSP控制器的事件管理单元 42.1.5. 软件设计方法 62.2. MPPT的控制方法与参数计算 72.3. 同频、同相的控制方法和参数计算 8
标签： tms320f2812 光伏 并网发电 模拟 protel pcb
上传时间： 2021-11-02
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This Section covers the design of power transformers used in buck-derived topologies: forward converter, bridge, half-bridge, and full-wave centertap. Flyback transformers (actually coupled inductors) are covered in a later Section. For more specialized applications, the principles discussed herein will generally apply.
上传时间： 2021-12-16
上传用户：fliang
Assessment of the Possible Health Effects of Ground Wave Emergency Network (1993)
上传时间： 2022-02-18
上传用户：trh505
结构体的具体尺寸如下所示：a=1.20h=0.620其中介质锥的介电常数E=2.0。选定工作频率为f=15GHz相对应的真空中的波长为0=20mm，这样结构体的儿何尺寸己经完全确定，下面介绍求解的全过程选定求解方式为（Solution Type）Driven modal1.建立所求结构体的几何模型（单位：mm）。由于此结构体的几何形状较简单，使用工具栏中的Draw命令可直接画出，这里不再赘述述。画出的结构体如图4.1.2所示。2.充结构体的材料选定结构体中的锥体部分，添加其介电常数Er=20的介质材料注：如果HSS中没有提供与所需参数完全相同的材料，用户可以通过新建材料或修改已有材料，使其参数满足用户需求设定结构体的边界条件及其激励源a.选定结构体的贴片部分，设定其为理想导体（PerE）。b.画出尺寸为X×Y×Z=70mm×70mm×40mm的长方体作为辐射边界，并设定其边界条件为辐射边界条件（Radiation Boundary）。c.由于要求出结构体的RCS，因此设定激励源为平面入射波（Incident Wave Source）。如图4.1.3所示。4.设定求解细节，检验并求解a.设定求解过程的工作频率为f=15GHz.其余细节设定如图4.1.4所示。b.设定远区辐射场的求解（Far Field Radiation Sphere栏的设定）。c.使用 Validation check命令进行检验，无错误发生，下一步运行命令 Analyze，对柱锥结构体进行求解。如图4.1.5和4.1.6所示。
上传时间： 2022-03-10
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数字示波器功能强大,使用方便,但是价格相对昂贵。本文以Ti的MSP430F5529为主控器,以Altera公司的EP2C5T144C8 FPGA器件为逻辑控制部件设计数字示波器。模拟信号经程控放大、整形电路后形成方波信号送至FPGA测频,根据频率值选择采用片上及片外高速AD分段采样。FPGA控制片外AD采样并将数据输入到FIFO模块中缓存,由单片机进行频谱分析。测试表明:简易示波器可以实现自动选档、多采样率采样、高精度测频及频谱分析等功能。Digital oscilloscope is powerful and easy to use, but also expensive. The research group designed a low-cost digital oscilloscope, the chip of MSP430F5529 of TI is chosen as the main controller and the device of EP2C5T144C8 of Altera company is used as the logic control unit. Analog signal enter the programmable amplifier circuit, shaping circuit and other pre-processing circuit. The shaped rectangular wave signal is sent to FPGA for measure the frequency. According to the frequency value to select AD on-chip or off-chip high-speed AD for sampling. FPGA controls the off-chip AD sampling and buffers AD data by FIFO module. The single chip microcomputer receives the data, and do FFT for spectrum analysis. The test shows that the simple oscilloscope can realize automatic gain selection, sampling at different sampling rates, high precision frequency measurement and spectrum analysis.
上传时间： 2022-03-27
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超声波换能器作为一种实用的检测手段，能实现声波所携带的信息和电能之间转换。它的性能优良，价格低廉，操作方便，易于调试，因此在工农业生产中发挥着重要的作用。但目前换能器驱动电路的发射频率多为40 kHz，本文针对1 MHz的超声波换能器电路进行了设计，主要介绍了它的发射驱动电路和接收驱动电路的设计方案，并对它们的功能进行了详细地说明。最后搭建实验平台，并对电路的输入、输出模块进行了测试。实验结果表明，换能器电路运行良好，可以为超声波高精度测量领域的应用提供参考。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...
上传时间： 2022-04-28
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说明： 用单片机实现波形发生器，含电路图，原理图，源码(generate wave)
上传时间： 2022-05-27
上传用户：zhanglei193
1-1前言一般人所能夠感受到聲音的頻率約介於5H2-20KHz，超音波（Ultrasonic wave）即爲頻率超過20KHz以上的音波或機械振動，因此超音波馬達就是利用超音波的彈性振動頻率所構成的制動力。超音波馬達的内部主要是以壓電陶瓷材料作爲激發源，其成份是由鉛（Pb）、结（Zr）及钛（Ti）的氧化物皓钛酸铅（Lead zirconate titanate，PZT）製成的。將歷電材料上下方各黏接彈性體，如銅或不銹鋼，並施以交流電壓於壓電陶瓷材料作爲驅動源，以激振彈性體，稱此結構爲定子（Stator），將其用彈簧與轉子Rotor）接觸，將所産生摩擦力來驅使轉子轉動，由於壓電材料的驱動能量很大，並足以抗衡轉子與定子間的正向力，雖然伸縮振幅大小僅有數徵米（um）的程度，但因每秒之伸縮達數十萬次，所以相較於同型的電磁式馬達的驅動能量要大的許多。超音波馬達的優點爲：1，轉子慣性小、響應時間短、速度範圍大。2，低轉速可產生高轉矩及高轉換效率。3，不受磁場作用的影響。4，構造簡單，體積大小可控制。5，不須經過齒輸作減速機構，故較爲安静。實際應用上，超音波馬達具有不同於傳統電磁式馬達的特性，因此在不適合應用傳統馬達的場合，例如：間歇性運動的裝置、空間或形狀受到限制的場所；另外包括一些高磁場的場合，如核磁共振裝置、斷層掃描儀器等。所以未來在自動化設備、視聽音響、照相機及光學儀器等皆可應用超音波馬達來取代。
标签： 超声波电机
上传时间： 2022-06-17
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