The field of digital communication has evolved rapidly in the past few decades, with commercial applications proliferating in wireline communi- cation networks (e.g., digital subscriber LOOP, cable, fiber optics), wireless communication (e.g., cell phones and wireless local area networks), and stor- age media (e.g., compact discs, hard drives). The typical undergraduate and graduate student is drawn to the field because of these applications, but is often intimidated by the mathematical background necessary to understand communication theory.
标签： Communication Fundamentals Digital of
上传时间： 2020-05-27
上传用户：shancjb
Public telephone operators and new independent wireless operators through- out the world are deploying wireless access in an effort to drastically reduce delivery costs in the most expensive part of the network?the local LOOP. Available radio technology enables both existing and new entrants to access subscribers in a rapid manner and deliver their basic telephony products and broadband-enhanced services.
标签： Transmission Handbooks Systems Design
上传时间： 2020-06-01
上传用户：shancjb
PLL(Phase Locked LOOP)： 为锁相回路或锁相环，用来统一整合时钟信号，使高频器件正常工作，如内存的存取资料等。PLL用于振荡器中的反馈技术。 许多电子设备要正常工作，通常需要外部的输入信号与内部的振荡信号同步。一般的晶振由于工艺与成本原因，做不到很高的频率，而在需要高频应用时，由相应的器件VCO，实现转成高频，但并不稳定，故利用锁相环路就可以实现稳定且高频的时钟信号。
上传时间： 2021-07-23
上传用户：紫阳帝尊
Wherever possible the overall technique used for this series will be "definition by example" withgeneric formulae included for use in other applications. To make stability analysis easy we will usemore than one tool from our toolbox with data sheet information, tricks, rules-of-thumb, SPICESimulation, and real-world testing all accelerating our design of stable operational amplifier (op amp)circuits. These tools are specifically targeted at voltage feedback op amps with unity-gain bandwidths<20 MHz, although many of the techniques are applicable to any voltage feedback op amp. 20 MHz ischosen because as we increase to higher bandwidth circuits there are other major factors in closing theLOOP: such as parasitic capacitances on PCBs, parasitic inductances in capacitors, parasitic inductancesand capacitances in resistors, etc. Most of the rules-of-thumb and techniques were developed not justfrom theory but from the actual building of real-world circuits with op amps <20 MHz.
标签： 运算放大器
上传时间： 2021-11-01
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ADC模数转换器件Altium Designer AD原理图库元件库SV text has been written to file : 4.4 - ADC模数转换器件.csvLibrary Component Count : 29Name Description----------------------------------------------------------------------------------------------------ADC0800 National 8-Bit Analog to Digital ConverterADC0809 ADC0831 ADCADC0832 ADC8 Generic 8-Bit A/D ConverterCLC532 High-Speed 2:1 Analog MultiplexerCS5511 National 16-Bit Analog to Digital ConverterDAC8 Generic 8-Bit D/A ConverterEL1501 Differential line Driver/ReceiverEL2082 Current-Mode MultiplierEL4083 Current Mode Four Quadrant MultiplierEL4089 DC Restored Video AmplifierEL4094 Video Gain Control/FaderEL4095 Video Gain Contol/Fader/MultiplexerICL7106 LMC6953_NSC PCI Local Bus Power SupervisorMAX4147 300MHz, Low-Power, High-Output-Current, Differential Line DriverMAX4158 350MHz 2-Channel Video Multiplexer-AmplifierMAX4159 350MHz 2-Channel Video Multiplexer-AmplifierMAX4258 250MHz, 2-Channel Video Multiplexer-AmplifierMAX4259 250MHz 2-Channel Video Multiplexer-AmplifierMAX951 Ultra-Low-Power, Single-Supply Op Amp + Comparator + ReferenceMAX952 Ultra-Low-Power, Single-Supply Op Amp + Comparator + ReferenceMC1496 Balanced Modulator/DemodulatorPLL100k Generic Phase Locked LOOPPLL10k Generic Phase Locked LOOPPLL5k Generic Phase Locked LOOPPLLx Generic Phase Locked LOOP水位计
标签： adc 模数转换 altium designer
上传时间： 2022-03-13
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HX711_1Kg#include "HX711.h"float Weight = 0;void setup(){ Init_Hx711(); //初始化HX711模块连接的IO设置 Serial.begin(9600); Serial.print("Welcome to use!\n"); delay(3000); Get_Maopi(); //获取毛皮}void LOOP(){ Weight = Get_Weight(); //计算放在传感器上的重物重量 Serial.print(float(Weight/1000),3); //串口显示重量 Serial.print(" kg\n"); //显示单位 Serial.print("\n"); //显示单位 delay(1000); //延时1s}
上传时间： 2022-03-20
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以STM32F103C8T6为核心,设计了无刷直流电机控制器硬件电路。电路主要包括IR2310构成的PWM驱动电路、IRF3808构成的逆变电路、增量式旋转编码构成的速度反馈电路。控制器具有CAN和RS232通信接口,可与计算机或PLC构成速度或位置伺服系统。利用由xPC目标搭建的半实物仿真平台对PI参数进行整定。测试了控制器的速度伺服响应性能,给定速度为2400rpm时,控制器响应时间为0.32s。实验结果表明,系统工作可靠,稳定性好,响应速度快,可以满足上肢康复机器人的机械臂速度控制性能要求。The hardware circuit of Brushless DC motor controller is designed by taking STM32F103C8T6 as the core,which mainly includes PWM driving circuits made up of IR2310,inverter circuit formed by IRF3808,speed feedback circuit composed of incremental rotary encoder and so on.Speed servo control system or position servo control system can be composed of BLDM controller with computer or PLC through CAN communication interface or RS232 serial communication interface.By using the hardware in the LOOP simulation platform built by xPC target,the PI parameters are set up.The Speed servo response performance of the controller is tested.When the speed is 2 400 rpm,the response time of the controller is 0...
上传时间： 2022-05-07
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Abstract: A sliding mode observer and fractional-order phase-locked LOOP (FO-PLL) method is proposed for the sensorless speed control of a permanent magnet synchronous motor (PMSM).The saturation function is adopted in order to reduce the chattering phenomenon caused by the sliding mode observer. In this proposed FO-PLL, method, a regulable fractional order r is involved, which means that the FO-PLL provides an extra degree of freedom. In fact, the conventional phase-locked LOOP (PLL) applied in sensorless PMSM control can be seen as a special case of the proposed FO-PLL. By selecting a proper fractional order r a better performance may be achieved. The computer simulation results demonstrate the effectiveness of the proposed method.Key words: fractional calculus; fractional order phase-locked LOOP; sensorless control; sliding mode observer; permanent magnet synchronous motor; speed controll
上传时间： 2022-06-18
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一.基础理论锁相环路（Phase Locked LOOP）是一个闭环的相位控制系统，它的输出信号的相位能自动跟踪输入信号相位。系统框图如下：当0，（1）与0：（1）相等时，两矢量以相同的角速度旋转，相对位置，即夹角维持不变，通常数值又较小，这就是环路的锁定状态。从输入信号加到锁相环路的输入端开始，一直到环路达到锁定的全过程，称为捕获过程。设系统最初进入同步状态[2nrtto，e，.]的时间为1。。那么从1=1，的起始状态到达进入同步状态的全部过程就称为锁相环路的捕获过程。捕获过程所需的时间T，=1，-1，称为捕获时间。显然，捕获时间T，的大小不但与环路的参数有关，而且与起始状态有关。对一定的环路来说，是否能通过捕获而进入同步完全取决于起始频差8.（4）-Ao。。若Ao，超过某一范围，环路就不能捕获了。这个范围的大小是锁相环路的一个重要性能指标，称为环路的捕获带Ao，。
标签： 射频锁相环
上传时间： 2022-06-21
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Agenda■Motor Types Overview■BLDC Motor Applications■Comparison of DC to Brushless DC Motors■Hall Sensors■Six-Step Commutation■Sensorless Commutation with Back-EMFVector Motor Control basicsClosed-LOOP Speed Control■Introduction to BLDC Motor Control Evaluation Kit■SummaryAll the popular motor types have their specific applications, and all can be controlled with microcontrollers.We wll talk about Brushless DC motors as it is the fast growing motor type today.Motors used in modern Air conditioners, home appliances, tools, even electric bikes are all going to Brushless DC.
上传时间： 2022-07-07
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