Today wireless is becoming the leader in communication choices among users. It is not anymore a backup solution for nomadic travellers but really a newmoodnaturallyusedeverywhereevenwhenthewiredcommunicationsare possible. Many technologies evolve then continuously, changing the telecom- munication world. We talk about wireless local area networks (WLANs), wire- less personal area networks (WPANs), wireless metropolitan area networks (WMANs), wireless wide area networks (WWANs), mobile ad hoc networks (MANETs), wireless sensor networks (WSNs) and mesh networks. Since we can find today a multitude of wireless technologies we decided to group a numberofcomplementarytechnologiesintoonedocumenttomakeiteasierfor areadertounderstandsomeofthetechnicaldetailsofeachmedia.
標(biāo)簽： TM Bluetooth Zigbee Wi-Fi WiMax and
上傳時間： 2020-06-01
上傳用戶：shancjb
During the past three decades, the world has seen signifi cant changes in the telecom- munications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from fi rst-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wire- less personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs).
標(biāo)簽： Communications Networking Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
Although the origins of radio frequency based wireless networking can be traced back to the University of Hawaii’s ALOHANET research project in the 1970s, the key events that led to wireless networking becoming one of the fastest growing technologies of the early 21st century have been the ratification of the IEEE 802.11 standard in 1997, and the subsequent development of interoperability certification by the Wi-Fi Alliance (formerly WECA).
標(biāo)簽： Networking Technology Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
Broadband powerline communication systems are continuing to gain significant market adoption worldwide for applications ranging from IPTV delivery to the Smart Grid. The suite of standards developed by the HomePlug Powerline Alliance plays an important role in the widespread deployment of broadband PLC. To date, more than 100 million HomePlug modems are deployed and these numbers continue to rise.
上傳時間： 2020-06-06
上傳用戶：shancjb
The term “ smart grid ” defi nes a self - healing network equipped with dynamic optimiza- tion techniques that use real - time measurements to minimize network losses, maintain voltage levels, increase reliability, and improve asset management. The operational data collected by the smart grid and its sub - systems will allow system operators to rapidly identify the best strategy to secure against attacks, vulnerability, and so on, caused by various contingencies. However, the smart grid fi rst depends upon identifying and researching key performance measures, designing and testing appropriate tools, and developing the proper education curriculum to equip current and future personnel with the knowledge and skills for deployment of this highly advanced system.
上傳時間： 2020-06-07
上傳用戶：shancjb
n recent years, there have been many books published on power system optimization. Most of these books do not cover applications of artifi cial intelligence based methods. Moreover, with the recent increase of artifi cial intelligence applications in various fi elds, it is becoming a new trend in solving optimization problems in engineering in general due to its advantages of being simple and effi cient in tackling complex problems. For this reason, the application of artifi cial intelligence in power systems has attracted the interest of many researchers around the world during the last two decades. This book is a result of our effort to provide information on the latest applications of artifi cial intelligence to optimization problems in power systems before and after deregulation.
標(biāo)簽： Intelligence Artificial System Power in
上傳時間： 2020-06-10
上傳用戶：shancjb
電路主要包括以下七個單元電路：正弦波產(chǎn)生電路、正弦波放大及電平變換電路、峰值檢測電路、增益控制電路、三角波產(chǎn)生電路、比較電路、低通濾波電路。正弦波產(chǎn)生電路采用文氏橋正弦波振蕩電路，由放大電路、反饋電路（正反饋）、選頻網(wǎng)絡(luò)（和反饋電路一起）、穩(wěn)幅電路構(gòu)成，它的振蕩頻率為：f=1/(2Π*RC)，由R4和C1構(gòu)成RC并聯(lián)振蕩，產(chǎn)生正弦波，與R5和C2構(gòu)成選頻網(wǎng)絡(luò)，同時R5和C2又構(gòu)成該電路的正反饋；穩(wěn)幅電路是由該電路的負(fù)反饋構(gòu)成，當(dāng)振幅過大時，二極管導(dǎo)通，R3短路，Av=1+（R2+R3）/R1減小，振幅減小，反之Av=1+（R2+R3）/R1增大，振幅增大，達(dá)到穩(wěn)幅效果，從而保證正弦波的正常產(chǎn)生。正弦波放大及電平變換電路由R10，R7分別與R15滑動電阻部分相連，通過滑動R15來分VCC和VEE的電壓，通過放大器正相來抬高或降低正弦波來達(dá)到特定范圍內(nèi)的幅值，滑動電阻R6與地相連，又與放大器反相端相連，滑動R6分壓來改變振幅，后又由R9和R8構(gòu)成反饋來達(dá)到放大的效果，從而達(dá)到正弦波放大及電平變化的目的。峰值檢測電路是由正弦波放大及電平變換電路產(chǎn)生的正弦波送入電壓跟隨器的正相端，通過兩個反向二極管后再連電容，快速充放電達(dá)到峰值，然后再送回正弦波放大及電平變換電路的反相端，構(gòu)成負(fù)反饋，達(dá)到增益穩(wěn)幅控制效果三角波產(chǎn)生電路主要由兩個NPN型三極管Q3Q4，一個PNP型三極管Q2，兩個電容C3C4，兩個非門，一個滑動電阻R16組成，通過充放電后經(jīng)過非門產(chǎn)生三角波。比較電路產(chǎn)生的正弦波送入放大器的正相端，產(chǎn)生的三角波送入放大器的反相端，通過作差比較產(chǎn)SPWM波，后又經(jīng)過由R22和C8組成的低通濾波電路，還原正弦波。
上傳時間： 2021-10-30
上傳用戶：
Agilent 34401A Service Guide.pdfIEC Measurement Category II includes electrical devices connected to mains at an outlet on a branch circuit. Such devices include most small appliances, test equipment, and other devices that plug into a branch outlet or socket. The 34401A may be used to make measurements with the HI and LO inputs connected to mains in such devices, or to the branch outlet itself (up to 300 VAC). However, the 34401A may not be used with its HI and LO inputs connected to mains in permanently installed electrical devices such as the main circuit-breaker panel, sub-panel disconnect boxes, or permanently wired motors. Such devices and circuits are subject to overvoltages that may exceed the protection limits of the 34401A. Note: Voltages above 300 VAC may be measured only in circuits that are isolated from mains. However, transient overvoltages are also present on circuits that are isolated from mains. The Agilent 34401A are designed to safely withstand occasional transient overvoltages up to 2500 Vpk. Do not use this equipment to measure circuits where transient overvoltages could exceed this level. Additional Notices Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC This product complies with the WEEE Directive (2002/96/EC) marking requirement. The affixed product label (see below) indicates that you must not discard this electrical/electronic product in domestic household waste. Product Category: With reference to the equipment types in the WEEE directive Annex 1, this product is classified as a "Monitoring and Control instrumentation" product. Do not dispose in domestic household waste. To return unwanted products, contact your local Agilent office, or see www.agilent.com/environment/product for more information. Agilent 34138A Test Lead Set The Agilent 34401A is compatible with the Agilent 34138A Test Lead Set described below. Test Lead Ratings Test Leads - 1000V, 15A Fine Tip Probe Attachments - 300V, 3A Mini Grabber Attachment - 300V, 3A SMT Grabber Attachments - 300V, 3A Operation The Fine Tip, Mini Grabber, and SMT Grabber attachments plug onto the probe end of the Test Leads. Maintenance If any portion of the Test Lead Set is worn or damaged, do not use. Replace with a new Agilent 3413
標(biāo)簽： agilent
上傳時間： 2022-02-20
上傳用戶：
一種通用微型飛行控制器設(shè)計 105頁摘 要 微小型無人機(jī)(Micro／Mini UnmannedAerial Vehicle，M【，AV)在現(xiàn)代軍事和國民經(jīng)濟(jì)中發(fā) 揮著越來越重要的作用。飛行控制器是無人機(jī)系統(tǒng)的核心，它自動采集無人機(jī)的各種飛行參數(shù)， 輸出舵面／油門指令以控制無人機(jī)的姿態(tài)和軌跡，使無人機(jī)能在沒有人工操縱干預(yù)的情況下自主 飛行，完成預(yù)定的任務(wù)。因此，研制高性能的飛行控制器對改善無人機(jī)的飛行性能以及提高任 務(wù)完成效率都具有重要的意義。 本文著重研究一種通用微型飛行控制器(General Micro Flight Controller，GMFC)，以適用 于小型／微型固定翼飛行器、旋翼飛行器、飛艇以及移動機(jī)器人的控制。論文的主要工作涉及 GMFC的硬件設(shè)計與軟件實現(xiàn)，具體內(nèi)容包括： 1)分析了微型飛行控制器在國內(nèi)外的研究現(xiàn)狀和發(fā)展趨勢，根據(jù)任務(wù)需求和設(shè)計指標(biāo)確定 一種通用型、微型化、低功耗、高性能、低成本的嵌入式微型飛行控制器的整體方案。 2)設(shè)計了基于ARM的通用微型飛行控制器的硬件系統(tǒng)，包括主控模塊、慣性測量單元、 靜壓高度計、遙控信號接收單元、數(shù)據(jù)通信模塊、電源模塊、附加傳感器模塊等；完成了整個 控制器的PCB制作以及對所有電路的調(diào)試工作，使得系統(tǒng)運作正常。 3)研究了基于卡爾曼濾波算法的姿態(tài)參考系統(tǒng)，并對姿態(tài)參考系統(tǒng)的靜態(tài)性能和動態(tài)性能 進(jìn)行測試。 4)設(shè)計了小型四旋翼飛行器本體平臺并對其進(jìn)行動力學(xué)建模仿真； 5)在此基礎(chǔ)上，結(jié)合四旋翼飛行器試驗平臺設(shè)計了飛行控制律，開發(fā)了GMFC的軟件系 統(tǒng)，并開展物理實驗驗證。
標(biāo)簽： 飛行控制器
上傳時間： 2022-03-15
上傳用戶：zhaiyawei
設(shè)計了一種基于STM32F103單片機(jī)的甲醛檢測報警儀，采用ESP8266 Wi-Fi模塊實現(xiàn)通信連接與數(shù)據(jù)傳遞，采用M-01傳感器實時采集室內(nèi)環(huán)境的甲醛濃度，通過LCD12864液晶模塊顯示甲醛濃度，并在甲醛濃度超標(biāo)時進(jìn)行聲光報警。該甲醛檢測報警儀成本低，精度高，可以滿足室內(nèi)環(huán)境甲醛濃度監(jiān)測的需要。
上傳時間： 2022-04-28
上傳用戶：
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