數字控制的交流調速系統所選用的微處理器、功率器件及產生PWM波的方法是影響交流調速系統性能好壞的直接因素。在介紹了正弦脈寬調制(SPWM)技術的基礎上，設計了一種以8098單片機作為控制器，以智能功率模塊IPM為開關器件的變頻調速系統。通過軟件編程，產生正弦脈沖寬度調制波形來控制絕緣柵雙極晶體管的導通和關斷，從而達到控制異步電動機轉速的目的。實驗結果表明，該系統可調頻率調電壓，穩定度高，調速范圍寬，具有較強的實用價值 Abstract: AC variable speed with digital control systems used microprocessors， power devices and generate PWM wave is the direct factors of affecting the performance AC speed regulation system. On the basis of introducing the sinusoidal pulse width modulation (SPWM) technology，this paper designed variable speed system which used 8098 as a controller， intelligent power module IPM as switching device. Through software programming， resulting in sinusoidal pulse width modulation waveform to control the insulated gate bipolar transistor turn on and off， so as to achieve the purpose of speed control of induction motors. Experimental results show that the system can adjust frequency modulation voltage， high stability， wide speed range， has a strong practical value.
上傳時間： 2013-11-14
上傳用戶：ynwbosss
Designing read/write device (RWD) units for industrial RF-Identification applications is strongly facilitated by the NXP Semiconductors HITAG Reader Chip HTRC110. All needed function blocks, like the antenna driver, modulator demodulator and antenna diagnosis unit, are integrated in the HTRC110. Therefore only a minimum number of additional passive components are required for a complete RWD. This Application Note describes how to design an industrial RF-Identification system with the HTRC110. The major focus is dimensioning of the antenna, all other external components including clock and power supply, as well as the demodulation principle and its implementatio
上傳時間： 2013-10-22
上傳用戶：zhengjian
便攜式信號采集在機器健康診斷系統中有較高的應用價值。機器健康診斷的信號特點是包括低頻信號。本文研究是為了實現簡易而且低成本的低頻便攜式信號采集。以Microchip公司單片機PIC18F1320為核心設計信號采集電路，實現了信號的采集和保存。系統采用串行電可擦除芯片24LC32A保存數據，經過有線通信，信號數據由串行口通過MAX232芯片輸送到微型計算機接收和保存，最后繪制出信號波形。 微型計算機程序采用Visual Basic編程。研究成功采樣頻率為3 kHz的復雜信號，證明該方案符合設計要求。 Abstract: Portable signal acquisition is useful in machine health monitoring systems. The signal characteristics of machine health monitoring includes low frequency signals. The goal of this study is to realize simple, inexpensive and portable low frequency signal sampling. This paper provides the project of signal acquisition system design based on PIC18F1320 microcontroller manufactured by the Microchip Technology Incorporation to achieve signal sampling and storage. The system adopted EEPROM 24LC32A to store the signal data. The microcomputer received data via wired link with the MAX232 IC through the serial port. The microcomputer program, programmed in Visual Basic, received the data, stored it and plotted the signal. The study successfully samples 3kHz complicated signals and thus meets the design requirement.
上傳時間： 2013-11-19
上傳用戶：moerwang
針對煤礦井下調度及緊急救援系統的需求，以DTMF編解碼模塊為核心，設計了具有自動撥號功能的新型電話系統。該系統利用MT8880對DTMF信號的編解碼功能實現一鍵撥號和遠程設置，通過檢測振鈴和忙音信號，完成自動摘機和掛機過程，配合AGC等外圍電路達到話音清晰流暢的效果。 Abstract: To meet the demand for mine scheduling and emergency rescue system， with using DTMF signal codec as the core， a new telephone system was designed with automatic dialing function. In the system， the DTMF signal encoding and decoding function of MT8880 was used to achieve one-touch dialing and remote setting. The circuit detects the ringing and busy signal， and then completes automatic off-hook and hangup. With AGC(Automatic Gain Control) and other peripheral circuits， the voice was regulated to a clear and smooth effect.
上傳時間： 2014-11-18
上傳用戶：ly1994
為了提高傳統溫度控制系統的性能，將PID控制理論與嵌入式系統相結合，采用瑞薩電子公司的H8S/2166作為核心處理器，AD公司的AD7705以及熱敏電阻溫度傳感器作為溫度檢測單元，利用4×6小鍵盤、LCD顯示器和S1D13305液晶控制器達到良好的人機交互，設計出了一個應用于化工領域的嵌入式實時溫度控制系統。相比于傳統溫度控制系統，該系統提供了更強的計算能力和可擴展能力，采用增量PID控制算法實現復雜控制。通過實驗，該系統能達到0.1 ℃的溫度控制精度以及小于120 s的溫度穩定時間。 Abstract: In order to improve the performance of conventional temperature control system， combining PID control theory with embedded systems， using the Renesas Electronics Corp. H8S/2166 micro-controller as a core processors， AD7705 and thermistor temperature sensor as a temperature detection unit and 4×6 small keyboard， LCD and S1D13305 LCD controller as a good human-computer interaction， this paper designed an embedded real-time temperature control system which is applied in chemical industry. Compared with conventional temperature control system， this system provides more computing power and extensibility， and adopts PID control algorithm for complex control. Through the experiment， the system can reach temperature control accuracy of 0.1 ℃ and temperature stabilization time of less than 120 seconds.
上傳時間： 2014-12-26
上傳用戶：003030
為了使音頻信號分析儀小巧可靠，成本低廉，設計了以2片MSP430F1611單片機為核心的系統。該系統將音頻信號送入八階巴特沃茲低通濾波器，對信號進行限幅放大、衰減、電平位移、緩沖，并利用一單片機負責對前級處理后的模擬信號進行采樣，將采集得到的音頻信號進行4 096點基2的FFT計算，并對信號加窗函數提高分辨率，另一單片機負責對信號的分析及控制顯示設備。此設計精確的測量了音頻信號的功率譜、周期性、失真度指標，達到較高的頻率分辨率，并能將測量結果通過紅外遙控器顯示在液晶屏上。 Abstract: o make the audio signal analyzer cheaper， smaller and more reliable， this system sends the audio signal to the eight-order butterworth filter， and then amplifies， attenuates， buffers it in a limiting range， transfers the voltage level of the signal before utilizing two MSP430F1611 MCU to realize the audio analysis. One is charged for sampling and dealing with the processed audio signal collected by the 4096 point radix-2 FFT calculation and imposes the window function to improve the frequency resolution. The other one controls the display and realizes the spectrum， periodicity， power distortion analysis in high resolution which is displayed in the LCD screen through the infrared remote control.
上傳時間： 2013-12-11
上傳用戶：jasonheung
在航電系統維護過程中，為解決定位故障的效率和降低維修成本等問題，提出了基于ICD（Interface Control Document，接口控制文件）的1553B總線的信息監控系統模型。該系統運用數據采集卡對總線中傳輸的信號有無失真、偏差等電氣特性進行檢測，并使用1553B通訊卡通過測控軟件LabWindows/CVI編程與ICD數據庫的動態鏈接，實現總線信息的解析和故障的判斷。與傳統的維護過程相比，這種模型能夠從信號的電氣特性以及信息的解析等全方位的去檢測判斷故障的來源，并且能夠廣泛在其他1553B總線系統內擴展應用。驗證表明該監控系統可以對總線信息進行快速有效地監測分析，能滿足應用需求。 Abstract: In the process of avionics system maintenance， to solve the problems such as improving the efficiency of fast orientation to troubles and reducing maintenance cost， system of 1553B bus information monitor model based on ICD was proposed. The system observed whether the data which transmitted on the bus appear distortion and deviation by using data acquisition card. And using 1553B communication card programming of the measure software LabWindows/CVI and the dynamic linking of ICD database， message analysis and fault estimation could be realized. Compared with traditional maintenance， this model can all-dimensionally detect and analyze the source of faults from both electrical characteristics of the signal and message analysis， and it can be widely applied in the other 1553B system. Experiment shown that this monitor system can effectively detect and analyze the bus message and can meet the application requirements.
上傳時間： 2013-11-23
上傳用戶：18752787361
以C8051F020為核心處理器，設計無線傳感器網絡數據采集系統。系統采用SZ05-ADV型無線通訊模塊組建Zigbee無線網絡，結合嵌入式系統的軟硬件技術，完成終端節點的8路傳感器信號的數據采集。現場8路信號通過前端處理后，分別送入C8051F020的12位A/D轉換器進行轉換。經過精確處理、存儲后的現場數據，通過Zigbee無線網絡傳送到上位機，系統可達到汽車試驗中無線測試的目的。 Abstract: This paper designs a wireless sensor network system for data acquisition with C8051F020 as core processors.The system used SZ05-ADV wireless communication module，set up a Zigbee wireless network， combined with hardware and software technologies of embedded systems，completed the end-node 8-locale sensor signal data acquisition.Eight locale signals were sent separately into the 12-bit ADC of C8051F020 for conversion through front treatment.After accurate processing and storage，the locale data was transmitted to the host computer through Zigbee wireless.The system achieves the purpose of wireless testing in vehicle trial.
標簽： C8051F020 Zigbee 汽車測試 系統設計
上傳時間： 2013-11-23
上傳用戶：dsgkjgkjg
提出了一種以S3C2440A為核心處理器的銀行評價器的設計方案，并結合XILINX公司的XL95144XL型CPLD，輔助S3C2440A，實現該銀行評價器的各部分功能以及系統信號之間的相互協調。該評價器在系統設計上采用液晶屏顯示，代替了以往簡單的數碼管電路的顯示模式，在視覺上給人以全新的享受。同時，評價器增加了新的網絡供電方式，只要將評價器連接上網絡就可以正常工作，方便了客戶的使用。總之，此款銀行評價器采用了嵌入式系統的設計方案，大大豐富了系統功能，實現一個銀行評價器設計的新突破。 Abstract: S3C2440A of SamSung company is the core component of the embedded system. A design of bank assessor based on S3C2440A was provided in this paper. It used XL95144XL combined with S3C2440A to realize all the functions and coordination with system signals. This bank assessor used LCD to display instead of the former simple digital display and provided a new seusuous enjoment. Meanwhile，it provided a new method of network power supply，that the bank assessor could regularly work once it connected to the network，which is convenient for customers to use. In a word，this assessor takes embedded system，enriches the system’s functions and reclizes a new breakout.
標簽： S3C2440A
上傳時間： 2013-11-03
上傳用戶：taa123456
為提高溫度測量效率，降低系統的成本，擴展傳輸距離，設計出一種新型溫度采集系統。單片機通過控制具有單總線方式的溫度傳感器DS18B20實現對溫度的測量，同時單片機通過控制具有單總線方式300～450MHz頻率范圍內的MAX7044與MAX7033無線發射與接收芯片實現溫度數據的無線傳輸。與傳統溫度采集系統相比，該系統利用單總線方式連接，采用無線傳輸方式實現遠距離通信，易于系統的集成與擴展。實驗結果表明，該系統結構簡單、方便移植，能夠同時實現多達上百點溫度的測量與500m范圍的傳輸。 Abstract: To improve the temperature measurement efficiency and reduce system cost,expansion of transmission distance,a new type of temperature acquisition system is designed.Microcontroller controlled temperature sensor DS18B20which has a single-bus achieves temperature measurement,while microcontroller by controlled the MAX7044and MAX7033chip with a single-bus and having300~450MHz radiofrequency to achieve the wireless transmission of temperature data.Compared with conventional temperature acquisition system,the system uses single-bus connected,and uses wireless transmission means to achieve long-distance communications,easy-to-system integration and expansion.The experimental results show that the system is simple,convenient transplantation,and can be implemented in as many as a hundred-point temperature measure-ment and the transmission range of500meters.
上傳時間： 2013-10-29
上傳用戶：515414293
