介紹了一種基于C8051F020單片機的多路壓力測量儀。該測量儀選用電阻應變式壓力傳感器采集壓力信號，并經放大電路處理后送入C8051F020單片機，再由C8051F020單片機內部的A/D轉換器將采集到的壓力信號進行模數轉化，然后分別對數據進行存儲和顯示。該測量儀能測量6路壓力信號，并且各測量點都能單獨檢測和設置。由于采用了C8051F020單片機，簡化了硬件電路，增強了抗干擾能力，使得測量儀具有測量精度高，沖擊小等特點。 Abstract: A measurement apparatus for multi-channel pressure based on single chip microcomputer is introduced.It can measure 6 channels signal of the pressure，and the pressure measure points can be detection and located individually.The pressure signal sampling is obtained by resistor stress-type pressure sensors，the digital signals of 6 channels are collected through amplifying and adjustment circuit of pressure signals and internal integrated A/D converter of MCU.Finally，and it realizes the function to store and display data separately.C8051F020 was used to made hardware circuit simple，and it also enhanced the anti-interference ability.It features high precision and little impact.
上傳時間： 2013-11-16
上傳用戶：yare
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
為深入了解基于UC3854A控制的PFC變換器中的動力學特性，研究系統參數變化對變換器中分岔現象的影響，在建立Boost PFC變換器雙閉環數學模型的基礎上，用Matlab軟件對變換器中慢時標分岔及混沌等不穩定現象進行了仿真。在對PFC變換器中慢時標分岔現象仿真的基礎上，分析了系統參數變化對分岔點的影響，并進行了仿真驗證。仿真結果清晰地顯示了輸入整流電壓的幅值變化對系統分岔點的影響。 Abstract: In order to better understand the dynamics characteristic of power factor correction converter based on UC3854A， and make the way that parameters change influences the bifurcation phenomena of the system clearly. The math model of the two closed loop circuits to the Boost PFC （Power Factor Correction） converter controller was built. Then， with the help of Matlab， the simulation for nonlinear phenomena such as chaos and slow-scale bifurcation in the PFC converter was made. Finally the factors that have influence to the phenomenon of bifurcation under slow-scale in PFC converter were analyzed. The simulation results clearly show the parameters change influences the bifurcation point of the system.
上傳時間： 2013-10-17
上傳用戶：杜瑩12345
針對材料試驗機等設備中要求測量或控制材料拉伸或壓縮的位移，一般采用光電軸角編碼器檢測位置信號，輸出正交編碼脈沖信號。若采用其他方法檢測位置信號，必然導致電路設計復雜，可靠性降低。因此，提出一種基于LS7266R1的電子式萬能材料試驗機設計方案。給出了試驗機中的控制器工作原理，LS7266R1與單片機的接口硬件設計，以及主程序軟件流程圖。巧妙地把力量傳感器，位移傳感器等機械運動狀態的壓力或拉力以及位置坐標，變成了電壓信號和電脈沖數字信號，供A/D測量和LS7266R1計數，從而實現了獨立完成材料試驗控制或通過PC機串口命令完成材料試驗控制。 Abstract: Aiming at the requirement that the displacement of the tension and compression always be tested and controlled in the equipement such as material testing machine. The position signal was tested by photoelectric axial angle coder. Therefore， the paper proposes the design of electronic universal testing machine design based on LS7266R1. If the position signal detected by other methods， will inevitably lead to the circuit design complexity， reliability decreased. The work theory of the controller， the hardware interface design between LS7266R1 and single chip， and the flow chart of main program， are presented in this paper. The signal of the compression or tension power and displacement at working， which tested by power sensor and displacement sensor especially， is changed into electric voltage and electric pulse numerical signals. And these signals can be tested by A/D and counted by LS7266R1. Finally the test of the material properties can be controlled by itself， or controlled by the COM command of PC.
上傳時間： 2013-11-02
上傳用戶：yl1140vista
為了提高環境參數采集的自動化水平，提升效率，設計了無線傳感器系統。本系統運用了傳感器技術、通信技術和單片機技術，實現了對環境溫度、濕度、光照度以及可燃性氣體濃度等參數的檢測。它能夠實時地與上位機進行無線通信，滿足對環境參數實時監測的要求。 Abstract: In order to increase the degree of automation and improve the efficiency of the environment monitoring parameters，the wireless sensor system was developed.Combining with the technique of sensor,automatic monitoring，communication and single-chip microcomputer，it realized real-time monitoring environment parameters,such as temperature，humidity，illumination，concentration of com- bustible gas and so on.At the same time it can communicate with upper personal computers，satisfy the desire of real-time monitoring.
上傳時間： 2013-11-22
上傳用戶：longlong12345678
為解決輸油管道溫度壓力參數實時監測的問題，設計了以C8051F930單片機作為控制核心的超低功耗輸油管道溫度壓力遠程監測系統?，F場儀表使用高精度電橋采集數據，通過433 MHz短距離無線通信網絡與遠程終端RTU進行通信，RTU通過GPRS網絡與PC上位機進行遠程數據傳輸，在上位機中實現數據存儲和圖形化界面顯示，從而實現輸油管道溫度壓力參數的實時監測和異常報警。經實驗證明，該系統的12位數據采集精度滿足設計要求，漏碼率小于1%，正常工作時間超過5個月，能實時有效地監測輸油管道的溫度壓力參數，節省大量人工成本，有效預防管道參數異常造成的經濟損失和環境污染。 Abstract: In order to solve the problems on real-time monitoring of pipeline temperature and pressure parameters， the ultra-low power remote pipeline temperature and pressure monitoring system was designed by using the single chip processor C8051F930 as the control core. The high-precision electric bridge was used in field instruments for data collection， the 433MHz short-range wireless communication network was used to make communication between field instrument and RTU， the GPRS was used by the RTU to transmit data to the PC host computer， and the data was stored and displayed in the PC host computer， so the real-time monitoring and exception alerts of pipeline temperature and pressure parameters were achieved. The experiment proves that the system of which error rate is less than 1% over five months working with the 12-bit data acquisition accuracy can effectively monitor the pipeline temperature and pressure parameters in real time， it saves a lot of labor costs and effectively prevents environmental pollution and economic losses caused by abnormal channel parameters.
上傳時間： 2013-11-07
上傳用戶：cuibaigao
為解決傳統可視倒車雷達視頻字符疊加器結構復雜，可靠性差，成本高昂等問題，在可視倒車雷達設計中采用視頻字符發生器芯片MAX7456。該芯片集成了所有用于產生用戶定義OSD，并將其插入視頻信號中所需的全部功能，僅需少量的外圍阻容元件即可正常工作。給出了以MAX7456為核心的可視倒車雷達的軟、硬件實現方案及設計實例。該方案具有電路結構簡單、價格低廉、符合人體視覺習慣的特點。經實際裝車測試，按該方案設計的可視倒車雷達視場清晰、提示字符醒目、工作可靠，可有效降低駕駛員倒車時的工作強度、減少倒車事故的發生。 Abstract: A new video and text generation chip，MAX7456，was used in the design of video parking sensor in order to simplify system structure，improve reliability and reduce cost. This chip included all the necessary functions to generate user-defined OSDs and to add them into the video signals. It could be put into work with addition of just a small number of resistances and capacitors. This paper provided software and hardware implementation solutions and design example based on the chip. The system had the characteristics of simplicity in circuit structure，lower cost，and comfort for the nature of human vision. Loading road test demonstrates high video and text display quality and reliable performance，which makes the driver easy to see backward and reduces chance of accidents.
上傳時間： 2013-12-10
上傳用戶：qiaoyue
針對船舶氣象儀保障維修而設計的船舶氣象儀測試系統，包括信息處理終端、主儀器檢測模塊、傳感器檢測模塊，各個模塊都采用基于AVR單片機的嵌入式系統，模塊之間通過CAN總線進行通信。結果表明，船舶氣象儀測試系統能夠快速檢測船舶氣象儀故障，與單純依靠人工方式排查故障相比，故障檢測時間縮短了60%以上。 Abstract: The test system of ship meteorological instrument was developed to satisfy the maintenance of ship meteorological instruments，which composed of information processing terminal， testing module of main instrument and testing module of sensors. Each of these modules included an embedded system based on microcontroller of AVR series and communicated with other module by CAN bus. The results show that the test system can judge the fault of ship meteorological instrument quickly and shorten the fault detection time as much as 60% compared with simple manual troubleshooting.
上傳時間： 2013-11-23
上傳用戶：stvnash
提出一種基于單片機AT89C51SND1C的MP3播放系統的設計方案。單片機集成了專用的解碼器，使用K9F1208閃存作為外存儲器，放音電路采用CS4330，存儲文件通過播放器上的USB接口設備從PC機上直接下載，液晶顯示采用LCD1602。方案設計簡單，性價比高，低功耗，易擴展。由于采用的是通用單片機實現的，可以很容易地移植到其他微控制器系統中，有很強的市場競爭能力和實用價值。 Abstract: A MP3 player design based on microchip AT89C51SND1C was presented, which used K9F1208 Flash chip as the memory circuit and used CS4330 as play chip. Storage files were download from PC through USB interfaces player on the device，and the LCD/602 was used as display screen. This system had characteristics of simple design,low power,easy expand，low cost and high recognition. Using of universual microchip make it easy to transplant to other microcontrol system，and have strong market competitiom and practical value.
上傳時間： 2014-12-27
上傳用戶：佳期如夢
基于AT89C52單片機的步進電機控制系統設計 摘 要: 提出了一個由AT89C52單片機控制步進電機的實例。可以通過鍵盤輸入相關數據, 并根據需要, 實時對步進電機工作方式進行設置, 具有實時性和交互性的特點。該系統可應用于步進電機控制的大多數場合。實踐表明, 系統性能優于傳統的步進電機控制器。 關鍵詞: 單片機; 步進電動機; 直流固態繼電器; 實時控制 ABSTRACT: A stepp ing motor control system based on AT89C52 chip microcomputer was described.The data can be inputwith keyboard, and stepp ingmotorwas controlled by these data. According to the demand, users can set the workingmodel of stepp ingmotor in real2time. This system can be widely used in stepp ing motor controlling. The p ractice showed that the performance of this system outdid the tradi-tional stepp ing motor controller.
上傳時間： 2013-11-22
上傳用戶：vodssv
