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
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
單片機作為一種微型計算機，其內部具有一定的存儲單元（8031除外），但由于其內部存儲單元及端口有限，很多情況下難以滿足實際需求。為此介紹一種新的擴展方法，將數據線與地址線合并使用，通過軟件控制的方法實現數據線與地址線功能的分時轉換，數據線不僅用于傳送數據信號，還可作為地址線、控制線，用于傳送地址信號和控制信號，從而實現單片機與存儲器件的有效連接。以單片機片外256KB數據存儲空間的擴展為例，通過該擴展方法，僅用10個I/O端口便可實現，與傳統的擴展方法相比，可節約8個I/O端口。 Abstract: As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
上傳時間： 2014-12-26
上傳用戶：adada
為提高太陽能的利用率，以ATmega8單片機為控制核心，設計了一套光電跟蹤與視日運動軌跡跟蹤互補控制的雙軸太陽跟蹤器。該跟蹤器在晴天時，利用光敏電阻采集光強判斷太陽位置,控制步進電機實現光電跟蹤；在陰天時，采集時鐘器件PCF8583的時間信息,計算當前太陽位置來實現視日運動軌跡跟蹤。實驗表明：該太陽跟蹤器能在不同天氣狀況下對太陽進行較準確地跟蹤，能量接收效率提高了30%，達到充分利用太陽能的目的。 Abstract: To improve the utilization rate of solar energy，a kind of solar tracking controller which effectively combined the sun angle tracking and photo electric tracking based on ATmega8is designed.In the sunny days，the solar tracking con-troller determines the sun's position by using photosensitive resistances to collect light intensity and control stepper motors to achieve photo electric tracking，n cloudy days，it collects clock chip PCF8583time information to calculate the current position of the sun and achieve the sun angle tracking.Experimental results show the solar tracking controller accurately tracks the sun in different weather conditions，improves received energy efficiency by30%and reaches the purpose of full use of solar energy.
上傳時間： 2013-10-15
上傳用戶：urgdil
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
闡述了一個由上位PC機和AT89C52下位單片機組成的主從分布式溫度巡回檢測系統。主從機采用RS-485 串行通訊標準進行通信，可在下位單片機實現基本的溫度數據巡回檢測基礎上，由上位PC機實現綜合處理功能或擴展為遠程操作。整個系統具有巡檢速度快，擴展性好的特點。 Abstract: In this paper,a top PC and AT89C52 under-bit microcontrollers from the main component of the tour distributed temperature detection system is presented. Master and slave can use RS-485 serial communication standards for communications.Based on next-bit machine for basic goods temperature detected data Tour, the top can achieve the integrated treatment of PC functions or for the expansion of long-distance operation. The entire inspection system is fast, expansion.
上傳時間： 2013-10-13
上傳用戶：zhoujunzhen
Mega16是一款采用先進RISC精簡指令，內置A/D的8位單片機，可支持低電壓聯機 Flash和EEPROM 寫入功能；同時還支持 Basic和C 等高級語言編程。用它設計電子時鐘不僅成本低，硬件簡單，而且很容易實現系統移植。介紹了如何利用AVR系列單片機Mega16及1602字符液晶來設計電子時鐘的方法，同時給出了相應的電路原理及部分語言程序。 Abstract: ?Mega16 is a high-performance, low power consumption, the use of advanced RISC concise instructions, built-in A/D 8-bit microcontrollers, the on-line support for low-voltage Flash, EEPROM write function. Except Mega16 also support the Basic, C, and other high-level language programming.The electronic clock which is deisgned by Mega16 is not only low-cost, simple hardware, but easy to achieve system migration.The design method of electrioic clock based on the AVR Mega16 and character LCD1602 is introduced in this paper,and the corresponding circuit electrionic and some language program are given.
上傳時間： 2014-12-27
上傳用戶：zl5712176
基于CC1110單片機公交報站系統主要由CC1110單片機最小系統和WT588D語音模塊組成，提出了如何實現語音報站，通過無線通信SimpliciTI網絡協議實現公交站臺的自動播報和OLCD液晶顯示公交運行的各類信息。結果表明，該公交報站系統報站準確率99%，價格比同類產品下降了300%以上，系統組成結構簡單，提高了系統的抗干擾性和穩定性，也便于攜帶。 Abstract: The bus stop announcement system based on CC1110 MCU is composed of CC1110 MCU minimum system and WT588D voice module. How to achieve the voice announcing is put forward.The bus-stop will announce automatically and display on the OLCD by means of wireless communication SimpliciTI network protocol. As a result， the bus station stop announcement systems reported 99% accuracy rate， price of similar products declined by 300% or more， system of simple structure， improve the anti-jamming and stability of the power system， it is also portable.
上傳時間： 2013-10-21
上傳用戶：baby25825
為了在工業生產及過程控制中準確測量溫度，設計了一種基于低功耗MSP430單片機的數字溫度計。整個系統通過單片機MSP430F1121A控制DS18B20讀取溫度，采用數碼管顯示，溫度傳感器DS18B20與單片機之間通過串口進行數據傳輸。MSP430系列單片機具有超低功耗，且外圍的整合性高，DS18B20只需一個端口即可實現數據通信，連接方便。通過多次實驗證明，該系統的測試結果與實際環境溫度一致，除了具有接口電路簡單、測量精度高、誤差小、可靠性高等特點外，其低成本、低功耗的特點使其擁有更廣闊的應用前景。 Abstract: In order to obtain accurate measuring temperature in industrial production and process control， a digital thermometer based on MSP430 MCU is designed. The system uses MSP430F1121A MCU to control DS18B20， and gets the temperature data， which is displayed on the LED. The temperature sensor DS18B20 and MCU transmit data through serial communication. MSP430 series has ultra-low power and high integration， DS18B20 only needs one port to achieve data communication. Through many experimental results prove， this system is consistent with actual environment temperature. The system has characteristics of interface circuit simple， high measuring accuracy， minor error， high reliability， besides， the characteristics of low cost and low power make it having vaster application prospect.
上傳時間： 2013-10-16
上傳用戶：wettetw
