The serious study of the practice of how to determine the appropriate content of a specification is a seldom-appreciated pastime. Those who have the responsibility to design a product would prefer a greater degree of freedom than permitted by the con- tent of a specification. Many of those who would manage those who would design a product would prefer to allocate all of the project funding and schedule to what they consider more productive labor. These are the attitudes, of course, that doom a project to defeat but they are hard to counter no matter how many times repeated by design engineers and managers. A system engineer who has survived a few of these experiences over a long career may retire and forget the past but we have an endur- ing obligation to work toward changing these attitudes while trying to offer younger system engineers a pathway toward a more sure success in requirements analysis and specification publishing.
标签： Requirements Analysis System
上传时间： 2020-06-01
上传用户：shancjb
Recent advances in wireless communication technologies have had a transforma- tive impact on society and have directly contributed to several economic and social aspects of daily life. Increasingly, the untethered exchange of information between devices is becoming a prime requirement for further progress, which is placing an ever greater demand on wireless bandwidth. The ultra wideband (UWB) system marks a major milestone in this progress. Since 2002, when the FCC allowed the unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency band, there has been significant synergistic advance in this technology at the cir- cuits, architectural and communication systems levels. This technology allows for devices to communicate wirelessly, while coexisting with other users by ensuring that its power density is sufficiently low so that it is perceived as noise to other users.
上传时间： 2020-06-01
上传用户：shancjb
A wireless ad-hoc network is a wireless network deployed without any infrastructure. In such a network, there is no access point or wireless router to forward messages among the computing devices. Instead, these devices depend on the ad-hoc mode of their wireless net‐ work interface cards to communicate with each other. If the nodes are within the transmis‐ sion range of the wireless signal, they can send messages to each other directly. Otherwise, the nodes in between will forward the messages for them. Thus, each node is both an end system and a router simultaneously.
上传时间： 2020-06-01
上传用户：shancjb
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
常用芯片DIP SOT SOIC QFP电阻电容二极管等3D模型库 3D视图封装库 STEP后缀三维视图（154个）:050-9.STEP0805R.STEP1001-1.STEP1001-2.STEP1001-3.STEP1001-4.STEP1001-5.STEP1001-6.STEP1001-7.STEP1001-8.STEP103_1KV.STEP10X5JT.STEP1206R.STEP13PX2.STEP15PX2.STEP20P插针.STEP25V1000UF.STEP3296W.STEP35V2200UF.STEP3mmLED.STEP3mmLEDH.STEP3X3可调电阻.STEP400V0.1UF.STEP455.STEP630V0.1UF.STEP7805.STEP8P4R.STEPAXIAL-0.2-0.125W.STEPAXIAL-0.4-0.25W.STEPaxial-0.6-2W.STEPB-3528.STEPC-0805.STEPC06x18.STEPCAP-6032.STEPCH3.96 X2.STEPCH3.96-3P.STEPD-PAK.STEPDB25.STEPDC-30.STEPDIP14.STEPDIP16.STEPDIP6.STEPDIP8.STEPDO-214AA.STEPDO-214AB.STEPDO-214AC.STEPDO-41.STEPDO-41Z.STEPFMQ.STEPGNR14D.STEPH9700.STEPILI4981.STEPIN4007.STEPIN5408.STEPJP051-6P6C_02.STEPJQC-3F.STEPJS-1132-10.STEPJS-1132-11.STEPJS-1132-12.STEPJS-1132-13.STEPJS-1132-14.STEPJS-1132-15.STEPJS-1132-2.STEPJS-1132-3.STEPJS-1132-4.STEPJS-1132-5.STEPJS-1132-6.STEPJS-1132-7.STEPJS-1132-8.STEPJS-1132-9.STEPJS-1132R-2.STEPJS-1132R-3.STEPJS-1132R-4.STEPJS-1132R-5.STEPJS-1132R-6.STEPJS-1132R-7.STEPJS-1132R-8.STEPJZC-33F.STEPKBP210.STEPKE2108.STEPKF2510 X8.STEPKF301.STEPKF301x3.STEPKSD-9700.STEPLED5_BLUE.STEPLED5_GRE.STEPLED5_RED.STEPLED5_YEL.STEPLFCSP_WQ.STEPLQFP100.STEPLQFP48.STEPMC-146.STEPmolex-22-27-2021.STEPmolex-22-27-2031.STEPmolex-22-27-2041.STEPmolex-22-27-2051.STEPmolex-22-27-2061.STEPmolex-22-27-2071.STEPmolex-22-27-2081.STEPMSOP10.STEPMSOP8.STEPPA0630NOXOX-HA1.STEPPIN10.STEPPIN24.STEPPIN24A.STEPR 0805.STEPR0402.STEPR0603.STEPR0805.STEPR1206.STEPRA-15.STEPRA-20.STEPRS808.STEPSIP-3-3.96 22-27-2031.STEPSL-B.STEPSL-D.STEPSL-E.STEPSL-G.STEPSL-H.STEPSOD-123.STEPSOD-323.STEPSOD-523.STEPSOD-723.STEPSOD-80.STEPSOIC-8.STEPSOP-4.STEPSOP14.STEPSOP16.STEPSOP18.STEPSOT-89.STEPSOT223.STEPSOT23-3.STEPSOT23-5.STEPSSOP28.STEPTAJ-A.STEPTAJ-B.STEPTAJ-C.STEPTAJ-D.STEPTAJ-E.STEPTAJ-R.STEPTHB6064H.STEPTO-126.STEPTO-126X.STEPTO-220.STEPTO-247.STEPTO-252-3L.STEPTOSHIBA_11-4C1.STEPTSSOP-8.STEPTSSOP14-BOTTON.STEPTSSOP14.STEPTSSOP28.STEPUSB-A.STEPUSB-B.STEPWT.STEP
标签： 芯片 dip sot soic qfp 电阻 电容 二极管 封装
上传时间： 2021-11-21
上传用户：XuVshu
数字化电源的特点：1.控制智能化它是以数字信号处理器(DSP)或微控制器(MCU)为核心，将数字电源驱动器及PWM控制器作为控制对象而构成的智能化开关电源系统。传统的由微控制器控制的开关电源，一般只是控制电源的启动和关断，并非真正意义的数字电源。2.数模组件组合优化采用“整合数字电源”(Fusion Digital Power)技术，实现了开关电源中模拟组件与数字组件的优化组合。例如，功率级所用的模拟组件MOSFET驱动器，可以很方便地与数字电源控制器相连并实现各种保护及偏置电源管理，而PWM控制器也属于数控模拟芯片。3.集成度高实现了电源系统单片集成化(Power System on Chip)，将大量的分立式元器件整合到一个芯片或一组芯片中。4.控制精度高能充分发挥数字信号处理器及微控制器的优势，使所设计的数字电源达到高技术指标。例如，其脉宽调制(PWM)分辨力可达150ps(10~12s)的水平，这是传统开关电源所望尘莫及的。数字电源还能实现多相位控制、非线性控制、负载均流以及故障预测等功能，为研制绿色节能型开关电源提供了便利条件。5.模块化程度高数字电源模块化程度高，各模块之间可以方便地实现有机融合，便于构成分布式数字电源系统，提高电源系统的可靠性。
标签： 全数字电源
上传时间： 2021-12-13
上传用户：XuVshu
SD卡 USB VGA DB9 RJ45 RJ22 通讯接口封装Altium Designer AD PCB封装库2D3D元件库文件PCB Library : 通讯接口.PcbLibDate : 2020/12/29Time : 14:31:34Component Count : 46Component Name-----------------------------------------------BM4-M003-BBM4-M003-BKBM4-M003-GBM4-M003-RBM4-M003-YDB9/P_ADB9/S_AMicro SDMICRO SIMMICRO SIM-BNano-SIM-ARJ-45A12RJ11-4P4C-LI-BKRJ11-4P4C-LI-GYRJ11-6P6C-BKRJ11-6P6C-GYRJ45_180RJ45-2RJ45-2LEDTF-1USB_A/P_AUSB_A/P_BUSB A/2-14USB A/2-17USB Type-C-6Pin_AUSB Type-C-16Pin_AUSB Type-C-24Pin_AUSB-A/S_AUSB-A/S_BUSB-A/S_CUSB-A/S_DUSB-A/S_EUSB-A/S_FUSB-B/S_AUSB-C/S_AUSB-C/S_BUSB-C/S_CUSB-micro_AUSB-MICRO_BUSB-micro_CUSB-MICRO_DUSB-MICRO_EUSB-MICRO_FUSB-MINI-AVGA15AVGA15B
上传时间： 2022-03-12
上传用户：得之我幸78
基于药物治疗在临床治疗中的重要性,分析目前服药提醒装置存在的不足,以STM32F103VET6单片机为控制核心,设计了一种多功能电子药箱。该系统包括显示模块、语音模块和数据存储模块。显示模块通过触摸屏电路和LED指示灯电路,与语音模块相配合,实现了服药提醒及指导的功能;数据存储模块通过EEPROM存储电路,能够实现掉电时服药信息不丢失的功能。并且为了实现电子药箱的智能化控制,开发了手机APP,两者之间可通过WIFI进行数据通信。经测试,该药箱能够有效地帮助慢性病患者按时、定量、正确服用药物,适合在家庭中推广使用,具有较高的应用价值和实践意义。Based on the importance of drug therapy in clinical treatment, this paper analyzes the shortcomings of current drug reminder devices, and designs a multi-function electronic medicine box with STM32 F103 VET6 microcontroller as the control core. The system includes a display module, a voice module, and a data storage module. The display module cooperates with the voice module through the touch screen circuit and the LED indicator circuit to realize the function of reminding and guiding the medicine;the data storage module can realize the function of not losing the medication information when the power is off through the EEPROM storage circuit.After testing, the medicine box can effectively help chronic diseases patients to take drugs on time, in a quantitative and correct manner,and is suitable for popularization in the family, and has high application value and practical significance.
标签： 电子药箱
上传时间： 2022-03-27
上传用户：
随着科技发展及工业4.0 进程推进,机械臂应用范围越来越广,并演化出各种各样的机械臂,如码垛机械臂、焊接机械臂、装配机械臂以及手术机械臂等。现利用solidworks 进行三维建模,设计制作一款基于stm32f103c8t6 单片机的主从式桌面级机械臂,该机械臂包括一个主动机械臂和一个从动机械臂,采用蓝牙传输信号方式进行同步运动,并且详细介绍了该机械臂材料选择、结构设计、工作原理、组成部分和设计特点。With the development of science and technology and the advancement of Industry 4.0, the application range of the mechanical arm has become wider and wider, and various types of mechanical arms, such as palletizing robot arms, welding robot arms, assembly robot arms, and surgical robot arms, have been developed. Now using solidworks for 3D modeling, design and manufacture a master-slave desktop-level robot arm based on stm32f103c8t6 single-chip microcomputer. The robot arm includes an active robot arm and a slave robot arm, which uses Bluetooth to transmit signals for synchronous motion. The material selection, structural design, working principle, components and design features of the manipulator are introduced.
标签： stm32f103c8t6 单片机
上传时间： 2022-03-27
上传用户：
入室抢劫事件屡见不鲜,针对此现象进行分析不难发现,造成失窃事件的极大原因是人们慵懒和意识差等不良性格造成习惯性不锁门.本文以STC89C52单片机为基础,设计了一种基于人体红外传感器的自动关门锁门装置,来解决此类问题.The incidents of burglary are so common. It is not difficult to find that the main reason for the burglary is the habit of unlocking of doors caused by people's laziness and poor consciousness. Based on the single chip microcomputer of STC89C52, a device used with infrared sensor of human body is introduced in this paper, which can achieve the effect of automatic closing and locking doors.
上传时间： 2022-03-27
上传用户：canderile
