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Low-frequency

  • Wireless Identification

    We are in the era of ubiquitous computing in which the use and development of Radio Frequency Iden- tification (RFID) is becoming more widespread. RFID systems have three main components: readers, tags, and database. An RFID tag is composed of a small microchip, limited logical functionality, and an antenna. Most common tags are passive and harvest energy from a nearby RFID reader. This energy is used both to energize the chip and send the answer back to the reader request. The tag provides a unique identifier (or an anonymized version of that), which allows the unequivocal identification of the tag holder (i.e. person, animal, or items).

    标签: Identification Wireless

    上传时间: 2020-06-08

    上传用户:shancjb

  • Fundamentals_of_Global_Positioning_System1

    The purpose of this book is to present detailed fundamental information on a global positioning system (GPS) receiver. Although GPS receivers are popu- larly used in every-day life, their operation principles cannot be easily found in one book. Most other types of receivers process the input signals to obtain the necessary information easily, such as in amplitude modulation (AM) and frequency modulation (FM) radios. In a GPS receiver the signal is processed to obtain the required information, which in turn is used to calculate the user position. Therefore, at least two areas of discipline, receiver technology and navigation scheme, are employed in a GPS receiver. This book covers both areas.

    标签: Fundamentals_of_Global_Positionin g_System_Receivers

    上传时间: 2020-06-09

    上传用户:shancjb

  • Control Systems

    Control Systems Engineering is an exciting and challenging field and is a multidisciplinary subject. This book is designed and organized around the concepts of control systems engineering using MATLAB, as they have been developed in the frequency and time domain for an introductory undergraduate or graduate course in control systems for engineer- ing students of all disciplines.

    标签: Control Systems

    上传时间: 2020-06-10

    上传用户:shancjb

  • Embedded_Deep_Learning_-_Algorithms

    Although state of the art in many typical machine learning tasks, deep learning algorithmsareverycostly interms ofenergyconsumption,duetotheirlargeamount of required computations and huge model sizes. Because of this, deep learning applications on battery-constrained wearables have only been possible through wireless connections with a resourceful cloud. This setup has several drawbacks. First, there are privacy concerns. Cloud computing requires users to share their raw data—images, video, locations, speech—with a remote system. Most users are not willing to do this. Second, the cloud-setup requires users to be connected all the time, which is unfeasible given current cellular coverage. Furthermore, real-time applications require low latency connections, which cannot be guaranteed using the current communication infrastructure. Finally, wireless connections are very inefficient—requiringtoo much energyper transferredbit for real-time data transfer on energy-constrained platforms.

    标签: Embedded_Deep_Learning Algorithms

    上传时间: 2020-06-10

    上传用户:shancjb

  • 轮机英语期末答案

    )Armature windings of the electric motor for NO.2 deck cargo winch found low insulation. Windings re-winded,painted and baked dry. (2) NO.1 main air compressor failed to build up pressure.The machine disassembled, cleaned and inspected. The discharge valve plate found broken. The valve palte renewed and running trials tested after being reassembled. 

    标签: 答案

    上传时间: 2020-07-14

    上传用户:

  • EN 300220-1V2.4.1

    EN 300220-1V2.4.1  Electromagnetic compatibility and Radio spectrum Matters (ERM);Short Range Devices (SRD);Radio equipment to be used in the 25 MHz to 1 000 MHz frequency range with power levels ranging up to 500 mW; Part 1: Technical characteristics and test methods

    标签: EMC

    上传时间: 2021-07-25

    上传用户:beiyouxia

  • HRVAS心率变异性

    HRVAS is a complete and self-contained heart rate variability analysis software (HRVAS) package. HRVAS offers several preprocessing options. HRVAS offers time-domeain, freq-domain, time-frequency, and nonlinear HRV analysis. All results can be exported to an Excel file. For processing many files HRVAS offers a bach processing feature. All settings/options can be saved to a .mat file and reloaded for future HRV analysis. Upon starting HRVAS all previously used settings/options are loaded.

    标签: HRVAS时频分析

    上传时间: 2021-09-19

    上传用户:boboo

  • 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

    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

    上传用户:

  • HX3248C

    FFeeaattuurreess  Input voltage range: 2.2 to 6V   Programmable LED Current   Drives LEDs Up to 27V   Switching Frequency:up to 800KHz  Wide dimming frequency range: 20KHz~  360 KHz   Programmable Overvoltage Protection   Tiny SOP8/PP Package

    标签: HX3248C

    上传时间: 2021-11-05

    上传用户:aben

  • SC3633

    Wide 2.2V to 6V Input Voltage Range „ 0.20V FB adjustable LED drive current „ Directly drive 9 Series 1W LED at VIN>=6V „ Fixed 800KHz Switching Frequency „ Max. 3A Switching Current Capability „ Up to 92% efficiency „ Excellent line and load regulation „ EN PIN TTL shutdown capability „ Internal Optimize Power MOSFET

    标签: sc3633

    上传时间: 2021-11-05

    上传用户:d1997wayne