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Half-wavelength

  • 步进电机驱动器原理图+PCB+驱动源码+使用教程等

    该步进电机驱动器又称为EasyDriver,EasyDriver能够为两级步进电机提供大约每相750mA(两极一共1.5A)的驱动。它默认设置为8步细分模式(所以如果你的电机是每圈200步,你使用EasyDriver时默认为每圈1600步),更多细分模式可以通过将MS1或MS2两个接脚接地进行设置。这是一种基于Allegro A3967驱动芯片的细分断路器。对于此设计的完整规格,请查阅A3967的参数表。它的最大每相电流从150mA到750mA。可以采用的最大驱动电压大概是30V,其中包括板载5V的调压器,所以只需要一个电源。质优价廉,这玩意儿只要十几美元,比你自己制作电路板更便宜。步进电机驱动器设计特色:· A3967 Microstepping Driver· MS1 and MS2 pins broken out to change microstepping resolution to full, half, quarter and eighth steps (defaults to eighth)· Compatible with 4, 6, and 8 wire stepper motors of any voltage· Adjustable current control from 150mA/phase to 700mA/phase· Power supply range from 6V to 30V. The higher the voltage, the higher the torque at high speeds

    标签: 步进电机 驱动器 pcb 驱动

    上传时间: 2022-04-27

    上传用户:ddk

  • 4G移动通信技术权威指南:LTE与LTE-Advanced.4G LTE.LTE

    PrefaceDuring the past years, there has been a quickly rising interest in radio access technologies for providingmobile as well as nomadic and fixed services for voice, video, and data. The difference indesign, implementation, and use between telecom and datacom technologies is also becoming moreblurred. One example is cellular technologies from the telecom world being used for broadband dataand wireless LAN from the datacom world being used for voice-over IP.Today, the most widespread radio access technology for mobile communication is digital cellular,with the number of users passing 5 billion by 2010, which is more than half of the world’s population.It has emerged from early deployments of an expensive voice service for a few car-borne users,to today’s widespread use of mobile-communication devices that provide a range of mobile servicesand often include camera, MP3 player, and PDA functions. With this widespread use and increasinginterest in mobile communication, a continuing evolution ahead is foreseen.This book describes LTE, developed in 3GPP (Third Generation Partnership Project) and providingtrue 4G broadband mobile access, starting from the first version in release 8 and through the continuingevolution to release 10, the latest version of LTE. Release 10, also known as LTE-Advanced,is of particular interest as it is the major technology approved by the ITU as fulfilling the IMTAdvancedrequirements. The description in this book is based on LTE release 10 and thus provides acomplete description of the LTE-Advanced radio access from the bottom up.Chapter 1 gives the background to LTE and its evolution, looking also at the different standardsbodies and organizations involved in the process of defining 4G. It also gives a discussion of the reasonsand driving forces behind the evolution.Chapters 2–6 provide a deeper insight into some of the technologies that are part of LTE and itsevolution. Because of its generic nature, these chapters can be used as a background not only for LTEas described in this book, but also for readers who want to understand the technology behind othersystems, such as WCDMA/HSPA, WiMAX, and CDMA2000.Chapters 7–17 constitute the main part of the book. As a start, an introductory technical overviewof LTE is given, where the most important technology components are introduced based onthe generic technologies described in previous chapters. The following chapters provide a detaileddescription of the protocol structure, the downlink and uplink transmission schemes, and the associatedmechanisms for scheduling, retransmission and interference handling. Broadcast operation andrelaying are also described. This is followed by a discussion of the spectrum flexibility and the associated

    标签: 4g 移动通信

    上传时间: 2022-07-07

    上传用户:lostxc

  • ZEMAX入门教学实例

    1-1单透镜这个例子是学习如何在ZEMAX里键入资料,包括设置系统孔径(System Aperture)、透镜单位(Lens Units)、以及波长范围(Wavelength Range),并且进行优化。你也将使用到光线扇形图(Ray Fan Plots)、弥散斑(Spot Diagrams)以及其它的分析工具来评估系统性能。这例子是一个焦距100mm、F/4的单透镜镜头,材料为BK7,并且使用轴上(On-Axis)的可见光进行分析。首先在运行系统中开启ZEMAX,默认的编辑视窗为透镜资料编辑器(Lens Data Editor,LDE),在LDE可键入大多数的透镜参数,这些设置的参数包括:·表面类型(Surf:Type)如标准球面、非球面、衍射光栅..等·曲率半径(Radius of Curvature)·表面厚度(Thickness):与下一个表面之间的距离·材料类型(Glass)如玻璃、空气、塑胶.…等:与下一个表面之间的材料

    标签: zemax

    上传时间: 2022-07-27

    上传用户:nicholas28