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
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
數字信號處理器dsPIC33F集多通道高精度A/D轉換、多通訊模式、看門狗、CMOS Flash技術等于一體，其內部可完成所有數據操作，實現總線不出芯片技術。將該處理器應用于微機保護裝置，提出基于dsPIC33F微處理器的微機保護裝置的設計方案，給出相應的接口電路與軟件流程。該設計方案結構簡單，性價比及可靠性高，開發周期短，具有一定的實用推廣價值。所研制的微機保護裝置現場運行效果良好。 Abstract: The dsPIC33F microprocessor has a plentiful interior resource which contains multi-channel，high precision A/D converters，multi-communication module，watchdog，CMOS Flash technology，and so on.All data manipulations is accomplished interiorly.What is more，it makes the technology that bus does not go beyond the chip comes into practice.The paper put forwards a design scheme based on dsPIC33F microprocessor.The scheme has the advantages of simple structure，high reliability and shortened exploitation cycle.What is more，it has definite practicality and reference.The microcomputer protection device has been put into operation with excellent effects.
上傳時間： 2013-11-16
上傳用戶：開懷常笑
前言 通用單片機，其實泛指微控器，對于芯片提供廠商，又指應用于通用領域的單片機產品；廣泛應用于家電產品、工業控制產品、儀器儀表設備、智能控制器等當中，滲透在人們的日常生活、生產活動當中。按照通用單片機的數據總線位數劃分，也分為4位、8位、16位以及32位通用單片機/微控制器，其中又以8位通用單片機在通用領域應用的市場當中，占據最大的份額；而且隨著需求的增漲，全球8位通用單片機的出貨量還在攀升當中。在8位通用單片機的供貨商中，有很多世界知名的芯片廠商，都在給廣大用戶提供各種規格的通用單片機產品，應用于各種領域；凌陽科技(Sunplus Technology Co.,Ltd.)作為全球知名的芯片設計公司，在通用單片機產品上，提供了SPMC系列通用單片機。
上傳時間： 2013-11-02
上傳用戶：gtzj
MMC/SD卡以其優越的性能，在單片機嵌入式設備中得到廣泛應用。將MMC/SD卡作為外部掉電存儲介質應用于音頻信號發生器中，通過8051F330單片機上的SPI接口，實現單片機—MMC/SD卡的存儲擴展，設計了此硬件平臺上的MMC/SD卡的單片機驅動程序，并給出了相應的程序代碼，滿足音頻信號發生器的大容量存儲要求。 Abstract: MMC/SD card is more and more widely used in the single chip embedded devices for their excellent performances.This article introduces the application of MMC/SD card as the external power down storage medium in audio signal generator. The extension technology especially for storage of single chip-MMC/SD card via SPI interfaces in 8051F330 single chip, including designs single chip drive program of MMC/SD card based on hardware platform,and also gives the key coding of the program. The implementation of big capacity storage is meaningful in audio signal generator.
上傳時間： 2014-12-27
上傳用戶：黃華強
為了解決磁放大器性能測試過程中，需要對其供給不同數值恒定電流的問題，設計了一種基于DAC7512和單片機的數控恒流源系統。該系統采用AT89C51作為主控器件，將計算機發送的電流控制字命令轉換為D/A轉換器控制字，通過模擬SPI通信接口，寫D/A控制字到DAC7512，從而控制其輸出相應數字電壓值，經差動縮放電路、電壓/電路變換電路和功率驅動電路，最后輸出恒定電流。實驗結果表明，恒流源輸出電流調節范圍為-45~+45 mA、精度為±0.1 mA，分辨率達0.024 4 mA，具有應用靈活，外圍電路簡單，可靠性高的特點。該數控直流恒流源也可為相關產品的測試系統研發提供參考。 Abstract: In order to solve the need to supply different values constant current for the magnetic amplifier in testing process， numerical control constant current source system was designed based on DAC7512 chip and microcontroller technology. The system used the AT89C51 as the main chip， which can convert the current control word from computer into to D/A control words. And the system wrote D/A control word into the DAC7512 chip to control the output voltage value by the SPI communication interface， which can output corresponding constant current figures by scaling circuit， the V/I converter and power drive circuit. Experimental results show that the current source output current adjustment range is -45~+45mA， accuracy is ± 0.1mA， and resolution ratio is 0.024 4mA
上傳時間： 2014-12-27
上傳用戶：invtnewer
以S3C825A為例介紹三星公司SAM8系列單片機的內部結構及其軟件開發環境，詳細描述采用混合編程法來對SAM8系列單片機進行軟件設計的一般方法，最后給出用混合編程法對S3C825A進行軟件設計的具體應用實例。 Abstract: With S3C825A,this paper firstly introduces the SAM8 series single-chip microcontrollers and their software development environment, then introduces mixed programming technology for SAM8 series single-chip microcontrollers. In the end, the application program is also given.
上傳時間： 2013-12-09
上傳用戶：ZZJ886
基于幅移鍵控技術ASK（Amplitude-Shift Keying），以C8051F340單片機作為監測終端控制器，C8051F330D單片機作為探測節點控制器，采用半雙工的通信方式，通過監控終端和探測節點的無線收發電路，實現數據的雙向無線傳輸。收發電路采用直徑為0.8 mm的漆包線自行繞制成圓形空心線圈天線，天線直徑為（3.4±0.3）cm。試驗表明，探測節點與監測終端的通信距離為24 cm，通過橋接方式，節點收發功率為102 mW時，節點間的通信距離可達20 cm。與傳統無線收發模塊相比，該無線收發電路在受體積、功耗、成本限制的場合有廣闊的應用前景。 Abstract: Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
上傳時間： 2013-10-19
上傳用戶：xz85592677
在需要實時大量輸入漢字的顯示控制處理應用中，利用傳統單片機實現顯示控制的設計方法是較難實現的。帶漢字字庫的液晶模塊的使用使得小容量ROM單片機的大量漢字信息輸入與顯示成為可能。提出了針對漢字字庫編碼的二級索引拼音輸入檢索方法,介紹了以ST7920作為控制器的帶漢字字庫的液晶顯示模塊的接口方法及漢字顯示和控制原理，給出了通用計算機鍵盤在單片機中的串行接口，采用該技術可大大增強單片機的漢字輸入功能。為小容量ROM單片機的大批量漢字信息處理提供了一種漢字輸入解決方案。 Abstract: It is difficult to realize Chinese characters input method based on the embedded system by using the traditional design method of display control. It is possible to input and display Chinese characters based on the embedded system with the ROM of small content by using the LCD module with Chinese characters.Chinese characters input method of the quadric index recall in allusion to Chinese characters code is brought forward.The interface and the principle of Chinese characters display control based on the LCD module controlled with the ST7920 is introduced too.The serial interface of the computer keyboard in common use and the embedded system is given at the same time. It can enhance the embedded system function of Chinese characters input by using this technology, and provide a kind of Chinese characters input scheme for the embedded system with small capacity ROM.
上傳時間： 2013-11-19
上傳用戶：jhksyghr
用戶對消費器和工業品人機界面的強勁需求使液晶顯示產品產場迅速升溫。為滿足這一市場需求，MICROCHIP TECHNOLOGY推出了一系列新型PIC單片機。
上傳時間： 2013-11-16
上傳用戶：siguazgb
