本系統采用電動機電樞供電回路串接采樣電阻的方式來實現對小型直流有刷電動機的轉速測量。該系統主要由二階低通濾波電路,小信號放大電路、單片機測量顯示電路、開關穩壓電源電路等組成。同時自制電機測速裝置,用高頻磁環作為載體,用線圈繞制磁環,利用電磁感應原理檢測電機運行時的漏磁,將變化的磁場信號轉化為磁環上的感應電流。用信號處理單元電路將微弱電信號轉化為脈沖信號,送由單片機檢測,從而達到準確測量電機的速度的要求。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.
標簽： 直流電動機
上傳時間： 2022-03-26
上傳用戶：
本系統基于STM32單片機設計的非接觸式電流檢測控制系統,通過OPA548片將所給任意信號放大,由100Ω電阻和INA128芯片進行電流電壓轉換放大后,利用STM32單片機對獲取的電壓信號以0.488μs頻率采樣,利用STM32單片機的FFT庫,獲得信號的諧波信息。測量電流信號精準,該設計可廣泛應用在以STM32單片機為核心控制器件的新型儀表中,性能精準且抗干擾能力強。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.
上傳時間： 2022-03-27
上傳用戶：
數字示波器功能強大,使用方便,但是價格相對昂貴。本文以Ti的MSP430F5529為主控器,以Altera公司的EP2C5T144C8 FPGA器件為邏輯控制部件設計數字示波器。模擬信號經程控放大、整形電路后形成方波信號送至FPGA測頻,根據頻率值選擇采用片上及片外高速AD分段采樣。FPGA控制片外AD采樣并將數據輸入到FIFO模塊中緩存,由單片機進行頻譜分析。測試表明:簡易示波器可以實現自動選檔、多采樣率采樣、高精度測頻及頻譜分析等功能。Digital oscilloscope is powerful and easy to use, but also expensive. The research group designed a low-cost digital oscilloscope, the chip of MSP430F5529 of TI is chosen as the main controller and the device of EP2C5T144C8 of Altera company is used as the logic control unit. Analog signal enter the programmable amplifier circuit, shaping circuit and other pre-processing circuit. The shaped rectangular wave signal is sent to FPGA for measure the frequency. According to the frequency value to select AD on-chip or off-chip high-speed AD for sampling. FPGA controls the off-chip AD sampling and buffers AD data by FIFO module. The single chip microcomputer receives the data, and do FFT for spectrum analysis. The test shows that the simple oscilloscope can realize automatic gain selection, sampling at different sampling rates, high precision frequency measurement and spectrum analysis.
上傳時間： 2022-03-27
上傳用戶：
電學中的測量技術涉及范圍非常廣,電流測量在電學計量中占有非常重要的位置。如何精確地進行電流測量是精密測量的一大難題。傳統的電流檢測電路多采用運算放大芯片與片外電流檢測電路相結合的方式,電路集成度很低,需要較多的接口和資源才能完成對電路的檢測。本文把所有電路部分都集成在一塊芯片上,包括檢測電阻,運算放大器電路及模擬轉數字轉換電路,從而在電路內部可以進行電流檢測,使電路更好的集成化。前置電路使用二級共源共柵結構的運算放大器,減小溝道長度調制效應造成的電流誤差。10位SAR ADC中采用電容驅動能力強的傳輸門保證了模數轉化器的有效精度。比較器模塊采用再生鎖存器與遲滯比較器作為基礎單元組合解決精密測量的問題。本設計可以作為嵌入芯片內的一小部分而檢測芯片中的微小電流1mA~100mA,工作電壓在1.8v左右,電流檢測精度預期達到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.
上傳時間： 2022-04-03
上傳用戶：
本文設計了一種磁致伸縮位移傳感器,介紹了該磁致伸縮位移傳感器的測量原理,通過結構優化設計提高了儀器的性能,詳述了硬件電路設計及實現方法,完成了軟件設計,實現了高壓充電、問詢脈沖加載、時間測量及濾波等功能,并通過實驗對其性能進行了驗證。所研制的磁致伸縮位移傳感器具有測量精度高、長期穩定性好等特點,滿足了大量程、高精度、惡劣環境等測量的要求。A kind of sensor based on magnetostrictive principle is designed.The measuring principle of the magnetostrictive displacement sensor is introduced,the performance of the instrument is improved by the structural optimization design,and introduced the hardware circuit design and the realization method,completed the software design,realized the functions of the high voltage charging,inquiries pulse loading,time measurement and filtering,and its performance is verified through the experiment.The magnetostrictive displacement sensor has the characteristics of high measuring precision.The sensor meets the requirements of large range,high precision,poor environment and so on.
標簽： 位移傳感器
上傳時間： 2022-04-06
上傳用戶：
高通(Qualcomm)藍牙芯片QCC5144_硬件設計詳細指導書（官方內部培訓手冊）其內容是針對硬件設計、部分重要元器件選擇(ESD，Filter）及走線注意事項的詳細說明。2 Power management 2.1 SMPS 2.1.1 Components specification 2.1.2 Input power supply selection 92.1.3 Minimize SMPS EMI emissions 2.1.4 Internal LDOs and digital core decoupling 2.1.5 Powering external components 2.2 Charger 2.2.1 Charger connections.2.2.2 General charger operation2.2.3 Temperature measurement during charging 2.3 SYS_CTRL 3 Bluetooth radio3.1 RF PSU component choice 3.2 RF band-pass filter3.3 Layout (天線 走線的注意事項)4 Audio4.1 Audio bypass capacitors 4.2 Earphone speaker output4.3 Line/Mic input 4.4 Headphone output optimizition5 LED pads 5.1 LED driver 5.2 Digital/Button input 5.3 Analog input5.4 Disabled 6 Reset pin (Reset#)7 USB interfaces7.1 USB device port7.1.1 USB device port7.1.2 Layout notes 7.1.3 USB charger detectionA QCC5144 VFBGA example schematic and BOM B Recommended SMPS components specificationB.1 Inductor specifition B.2 Recommended inductors B.3 SMPS capacitor specifition
上傳時間： 2022-04-07
上傳用戶：默默
INTERNATIONAL STANDARD NORME INTERNATIONALEPart 4-2: Testing and measurement techniques – Electrostatic discharge immunity test.About the IEC The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes International Standards for all electrical, electronic and related technologies.About IEC publications The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the latest edition, a corrigenda or an amendment might have been published.
標簽： IEC
上傳時間： 2022-04-19
上傳用戶：fliang
基于TMS320F28335的超聲波流量計硬件原理圖+軟件源碼本文以TMS320F28335 處理器為核心，設計一種用于管道流量測量的超聲波流量計。系統硬件由核心板，超聲波發射和接收電路，切換電路，超聲換能器，基于ADS805 的高速信號采集電路，人機交互以及電源等模塊構成。采用時差法進行管道流量測量，時差測量采用SCOT 加權的廣義互相關時延估計算法。本論文設計的超聲波流量計具有測量速度快、準確性好、成本低等優點。關鍵字：C2000，超聲波，流量，廣義互相關算法AbstractA kind of ultrasonic flowmeter using for the pipe flow measurement is designed based onTMS320F28335 in this paper. The system hardware consists of the following parts: the core board,ultrasonic signal transmitter and receiver circuits, switch circuit, ultrasonic transducer, signalacquisition circuit based on ADS805, human-computer interaction module and power supplymodule, etc. The system use the method of time difference for pipeline flow measurement and thetime difference is calculated by the time-delay algorithm of SCOT weighted generalizedcross-correlation. The ultrasonic flowmeter has the features of high testing speed, high precisionand low cost, etc.Keywords: C2000,Ultrasonic, Flow, Generalized Cross-Correlation Algorithm
標簽： tms320f28335 超聲波流量計
上傳時間： 2022-05-06
上傳用戶：
基于stm32的GPS基本數據處理+串口輸入，32與GPS用串口通信并解析得到經緯度，通過另一個串口輸入到電腦上?？梢宰约簩憘€上位機解析經緯度得出具體位置。另外說下，OpenLuat 的所有 GNSS 模塊均使用國際標準 (WGS-84)坐標系，所以開發者在國內常見地圖定位時，會發現與實際情況有幾十米的誤差。這并非模塊問題， 而是國內地圖采用了非標坐標系所致。國內常見地圖如高德地圖使用 GCJ-02（俗稱“火星坐標”。高德地圖，騰訊地圖，谷歌地圖（中國區域）使用該坐標） 坐標系， 百度地圖使用 BD-09 坐標系，故此開發者需要對模塊輸出的經緯度進行加偏處理，才能在國內的地圖上實現精確定位。推薦一個網站，http://www.openluat.com/GPS-Offset.html。
上傳時間： 2022-05-11
上傳用戶：
說明： 基于STM32單片機和DHT11傳感器的濕度測量，包括工程文件和源碼。(Based on the STM32 MCU and DHT11 sensor humidity measurement, including project files and source code.)
上傳時間： 2022-05-16
上傳用戶：
