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resistance

导体对电流的阻碍作用就叫该导体的电阻。电阻(resistance,通常用“R”表示)是一个物理量,在物理学中表示导体对电流阻碍作用的大小。导体的电阻越大,表示导体对电流的阻碍作用越大。不同的导体,电阻一般不同,电阻是导体本身的一种性质。导体的电阻通常用字母R表示,电阻的单位是欧姆,简称欧,符号为Ω。
  • 直流电动机测速装置

    本系统采用电动机电枢供电回路串接采样电阻的方式来实现对小型直流有刷电动机的转速测量。该系统主要由二阶低通滤波电路,小信号放大电路、单片机测量显示电路、开关稳压电源电路等组成。同时自制电机测速装置,用高频磁环作为载体,用线圈绕制磁环,利用电磁感应原理检测电机运行时的漏磁,将变化的磁场信号转化为磁环上的感应电流。用信号处理单元电路将微弱电信号转化为脉冲信号,送由单片机检测,从而达到准确测量电机的速度的要求。In this system, the sampling resistance of armature power supply circuit is connected in series to measure the speed of small DC brush motor. The system is mainly composed of second-order low-pass filter circuit, small signal amplifier circuit, single-chip measurement and display circuit, switching regulated power supply circuit and so on. At the same time, the self-made motor speed measuring device uses high frequency magnetic ring as the carrier, coil winding magnetic ring, and electromagnetic induction principle to detect the leakage of magnetic field during the operation of the motor, which converts the changed magnetic field signal into the induced current on the magnetic ring. The weak electric signal is transformed into pulse signal by signal processing unit circuit, which is sent to single chip computer for detection, so as to meet the requirement of accurate measurement of motor speed.

    标签: 直流电动机

    上传时间: 2022-03-26

    上传用户:

  • 基于STM32单片机设计的非接触式电流检测控制系统

    本系统基于STM32单片机设计的非接触式电流检测控制系统,通过OPA548片将所给任意信号放大,由100Ω电阻和INA128芯片进行电流电压转换放大后,利用STM32单片机对获取的电压信号以0.488μs频率采样,利用STM32单片机的FFT库,获得信号的谐波信息。测量电流信号精准,该设计可广泛应用在以STM32单片机为核心控制器件的新型仪表中,性能精准且抗干扰能力强。This system is a non-contact current detection and control system based on STM32 single chip microcomputer. It amplifiesany signal through OPA548 chip, converts and amplifies the current and voltage by 100 Ω resistance and INA128 chip. The obtainedvoltage signal is sampled at the frequency of 0.488 μs by STM 32 single chip microcomputer, and the harmonic information of the signalis obtained by the FFT library of STM 32 single chip microcomputer. The measurement of current signal is accurate. This design can bewidely used in a new instrument with STM 32 single chip microcomputer as its core control device, with accurate performance and stronganti-interference capability.

    标签: stm32 单片机

    上传时间: 2022-03-27

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  • 电流检测电路中运算放大器与ADC的设计

    电学中的测量技术涉及范围非常广,电流测量在电学计量中占有非常重要的位置。如何精确地进行电流测量是精密测量的一大难题。传统的电流检测电路多采用运算放大芯片与片外电流检测电路相结合的方式,电路集成度很低,需要较多的接口和资源才能完成对电路的检测。本文把所有电路部分都集成在一块芯片上,包括检测电阻,运算放大器电路及模拟转数字转换电路,从而在电路内部可以进行电流检测,使电路更好的集成化。前置电路使用二级共源共栅结构的运算放大器,减小沟道长度调制效应造成的电流误差。10位SAR ADC中采用电容驱动能力强的传输门保证了模数转化器的有效精度。比较器模块采用再生锁存器与迟滞比较器作为基础单元组合解决精密测量的问题。本设计可以作为嵌入芯片内的一小部分而检测芯片中的微小电流1mA~100mA,工作电压在1.8v左右,电流检测精度预期达到10uA的需求。The measurement technology in electricity involves a wide range,and current measurement plays a very important position in electrical measurement.How to accurately measure current is a big problem in precision measurement. The traditional current detecting circuit adopts the combination of the operational amplifier chip and theoff-chip current detecting circuit, The circuit integration is very low, and more interfaces and resources are needed tocomplete the circuit detection.This topic integrates all the circuit parts into one chip, including detection resistance, operational amplifier circuit andanalog to digital conversion circuit. Highly integrated circuit makes the external resources on the chip more intensive,so that current detection can be carried out inside the circuit, so that the circuit can be better integrated. Thefront-end circuit of this project uses two-stage cascade operational amplifier and cascade tube to reduce the currenterror caused by channel length modulation effect. In 10-bit SAR ADC, the transmission gate with strong capacitivedriving ability ensures the effective accuracy of the analog-to-digital converter. Comparator module uses regenerativelatch and hysteresis comparator as basic unit to solve the difficult problem of precision measurement. This topic can beused as a small part of the embedded chip to detect the micro-current in the chip 1 mA~100 mA, the working voltageis about 1.8v, and the current detection accuracy is expected to reach the requirement of 10 uA.

    标签: 电流检测 电路 运算放大器 adc

    上传时间: 2022-04-03

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  • 一种低成本高可靠的SFP+光收发模块电路研究与实现

    本文首次设计并验证了基于macom三合一芯片设计的光模块电路,该电路旨在提供一种满足SFF-8472中规定的数字诊断功能的低成本SFP+模块。电路采用激光器驱动、限幅放大器、控制器以及时钟恢复单元集成的单芯片,在保证高精度数字诊断功能基础上,实现了低成本高可靠的特点。该电路在光接收接口组件与激光器驱动和限幅放大器单元的限幅放大器部分之间接入滤波器来提高模块的灵敏度及信号质量。在控制器单元的数字电位器的引脚上采用外加电阻的方式避免出现上电不发光的故障问题。该研究结果为下一代SFP-DD光模块设计与开发工作,奠定了一定的理论与实践基础。This paper designs and validates the optical module circuit based on the MACOM Trinity chip for the first time.This circuit aims to provide a low-cost SFP module which meets the digital diagnosis function specified in SFF-8472.The circuit uses a single chip integrated with laser driver,limiting amplifier,controller and clock recovery unit.On the basis of ensuring high precision digital diagnosis function,it achieves the characteristics of low cost and high reliability.The circuit connects a filter between the optical receiving interface module and the limiting amplifier part of the laser driver and limiting amplifier unit to improve the sensitivity and signal quality of the module.The pin of the digital potentiometer in the controller unit is equipped with an external resistance to avoid the problem of power failure.The research results lay a theoretical and practical foundation for optical module design in high-speed data center.

    标签: sfp 光收发模块

    上传时间: 2022-04-03

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  • 万能模拟信号输入采集电路

    介绍一种万能模拟信号输入采集电路,可以同时支持电压、电流、热电偶、热电阻等常见的工业类型信号,方便后级电路的测量。该研究成果通过不断优化和完善,已成功应用到了中控仪表的新产品中。The paper introduces a collection circuit of universal signal input. The circuit support voltage, current, thermocouple, thermal resistance and other common industrial type signal. The research results, which has been continuous optimized and improved, has been successfully applied to the new production of Zhejiang Supcon Instrument Co., Ltd.

    标签: 采集电路

    上传时间: 2022-04-21

    上传用户:slq1234567890

  • 基于ICL8038等构成的函数发生器电路

    摘要:本系统以ICL8038集成块为核心器件,制作一种函数信号发生器,制作成本较低。适合学生学习电子技术测量使用。ICL8038是一种具有多种波形输出的精密振荡集成电路,只需要个别的外部元件就能产生从0.001Hz~30KlHz的低失真正弦波、三角波、矩形波等脉冲信号。输出波形的频率和占空比还可以由电流或电阻控制。另外由于该芯片具有调制信号输入端,所以可以用来对低频信号进行频率调制。关键词:函数信号发生器频率调制Abstract:The system ICL8038 integrated block as the core device,producing a kind of function signal generator,producing low cost.Suitable for students to learn the use of electronic technology measurement.ICL8038 is a kind of multi-precision oscillator waveform output integrated circuits,a separate external components only need to be able to generate from the 0.001Hz ~30KHz low-distortion sine wave,triangle wave,square wave pulse signal,etc..Output waveform of the frequency and duty cycle can also be controlled by a currentor resistance.In addition,as the chip has a modulated signal input terminal,it can be used to low-frequency signal is frequency modulation.

    标签: icl8038 函数发生器 电路

    上传时间: 2022-07-04

    上传用户:zhanglei193

  • hall元件NHE520F

    ・This is a high sensitivity type of Nicera Hall element using evaporated InSbfilm.・It performs effectively in low magnetic fields due to the high sensitivity.・The input and output resistance values are suitable for transistor circuitsBrushless motors・DVD drive, CD-ROM drive, floppy disk drive・Other small precision motors・Non-contacting magnetic sensors・Position sensors, rotation sensors, current sensors・Magnetic flux sensors other than those above

    标签: nhe520f

    上传时间: 2022-07-26

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  • 霍尔元件 NHE313 技术手册

    This is a high sensitivity type of Nicera Hall element using evaporated InSbfilm.It performs effectively in low magnetic fields due to the high sensitivity.The input and output resistance values are suitable for transistor circuits.Sip type packageApplications    Brushless motorsPosition sensors, rotation sensors, current sensorsNon-contacting magnetic sensorsCurrent sensorsMagnetic flux sensors other than those above

    标签: nhe313 霍尔元件

    上传时间: 2022-07-26

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  • 最新FPC生产流程介紹

    SMT(Surface mount technology)是可在“板面上”满及焊牢栖多敷“表面黏装零件的電子装配技术.侵贴:1.可在板上雨成同特焊接,封装密度提高50~70%.WW2.l短,提高博输速度3.可使用更高删敷.4.自勤化,快速,成本低.1.表面贴装零件SOIC(small outline integrate circle)resistance(電阻)CAPACITANCE(電容)AMPLCC(plastic leaded chip carriers)CONNECT etc.(结器)封装材料1.)陶瓷(BeO):精度高,密封度高(CTE:5~7PPM/℃)封板子熟膨服要求高2.)聚硫胺醚(Polyetherimide):一可用玻璃逛行封合的耐高温熟塑性塑廖,机械,電子性能侵良AwIR各波皆敏感,易分解,生“酸泡”现象.3.)熔融矽砂(Fused silica),暖氧横脂

    标签: fpc

    上传时间: 2022-07-27

    上传用户:zhaiyawei