介绍了一种基于C8051F020单片机的多路压力测量仪。该测量仪选用电阻应变式压力传感器采集压力信号，并经放大电路处理后送入C8051F020单片机，再由C8051F020单片机内部的A/D转换器将采集到的压力信号进行模数转化，然后分别对数据进行存储和显示。该测量仪能测量6路压力信号，并且各测量点都能单独检测和设置。由于采用了C8051F020单片机，简化了硬件电路，增强了抗干扰能力，使得测量仪具有测量精度高，冲击小等特点。 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.
上传时间： 2013-11-16
上传用户：yare
为了解决磁放大器性能测试过程中，需要对其供给不同数值恒定电流的问题，设计了一种基于DAC7512和单片机的数控恒流源系统。该系统采用AT89C51作为主控器件，将计算机发送的电流控制字命令转换为D/A转换器控制字，通过模拟SPI通信接口，写D/A控制字到DAC7512，从而控制其输出相应数字电压值，经差动缩放电路、电压/电路变换电路和功率驱动电路，最后输出恒定电流。实验结果表明，恒流源输出电流调节范围为-45~+45 mA、精度为±0.1 mA，分辨率达0.024 4 mA，具有应用灵活，外围电路简单，可靠性高的特点。该数控直流恒流源也可为相关产品的测试系统研发提供参考。 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
上传时间： 2014-12-27
上传用户：invtnewer
为深入了解基于UC3854A控制的PFC变换器中的动力学特性，研究系统参数变化对变换器中分岔现象的影响，在建立Boost PFC变换器双闭环数学模型的基础上，用Matlab软件对变换器中慢时标分岔及混沌等不稳定现象进行了仿真。在对PFC变换器中慢时标分岔现象仿真的基础上，分析了系统参数变化对分岔点的影响，并进行了仿真验证。仿真结果清晰地显示了输入整流电压的幅值变化对系统分岔点的影响。 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.
上传时间： 2013-10-17
上传用户：杜莹12345
针对材料试验机等设备中要求测量或控制材料拉伸或压缩的位移，一般采用光电轴角编码器检测位置信号，输出正交编码脉冲信号。若采用其他方法检测位置信号，必然导致电路设计复杂，可靠性降低。因此，提出一种基于LS7266R1的电子式万能材料试验机设计方案。给出了试验机中的控制器工作原理，LS7266R1与单片机的接口硬件设计，以及主程序软件流程图。巧妙地把力量传感器，位移传感器等机械运动状态的压力或拉力以及位置坐标，变成了电压信号和电脉冲数字信号，供A/D测量和LS7266R1计数，从而实现了独立完成材料试验控制或通过PC机串口命令完成材料试验控制。 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.
上传时间： 2013-11-02
上传用户：yl1140vista
为了提高环境参数采集的自动化水平，提升效率，设计了无线传感器系统。本系统运用了传感器技术、通信技术和单片机技术，实现了对环境温度、湿度、光照度以及可燃性气体浓度等参数的检测。它能够实时地与上位机进行无线通信，满足对环境参数实时监测的要求。 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.
上传时间： 2013-11-22
上传用户：longlong12345678
为解决输油管道温度压力参数实时监测的问题，设计了以C8051F930单片机作为控制核心的超低功耗输油管道温度压力远程监测系统。现场仪表使用高精度电桥采集数据，通过433 MHz短距离无线通信网络与远程终端RTU进行通信，RTU通过GPRS网络与PC上位机进行远程数据传输，在上位机中实现数据存储和图形化界面显示，从而实现输油管道温度压力参数的实时监测和异常报警。经实验证明，该系统的12位数据采集精度满足设计要求，漏码率小于1%，正常工作时间超过5个月，能实时有效地监测输油管道的温度压力参数，节省大量人工成本，有效预防管道参数异常造成的经济损失和环境污染。 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.
上传时间： 2013-11-07
上传用户：cuibaigao
为解决传统可视倒车雷达视频字符叠加器结构复杂，可靠性差，成本高昂等问题，在可视倒车雷达设计中采用视频字符发生器芯片MAX7456。该芯片集成了所有用于产生用户定义OSD，并将其插入视频信号中所需的全部功能，仅需少量的外围阻容元件即可正常工作。给出了以MAX7456为核心的可视倒车雷达的软、硬件实现方案及设计实例。该方案具有电路结构简单、价格低廉、符合人体视觉习惯的特点。经实际装车测试，按该方案设计的可视倒车雷达视场清晰、提示字符醒目、工作可靠，可有效降低驾驶员倒车时的工作强度、减少倒车事故的发生。 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.
上传时间： 2013-12-10
上传用户：qiaoyue
针对船舶气象仪保障维修而设计的船舶气象仪测试系统，包括信息处理终端、主仪器检测模块、传感器检测模块，各个模块都采用基于AVR单片机的嵌入式系统，模块之间通过CAN总线进行通信。结果表明，船舶气象仪测试系统能够快速检测船舶气象仪故障，与单纯依靠人工方式排查故障相比，故障检测时间缩短了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.
上传时间： 2013-11-23
上传用户：stvnash
提出一种基于单片机AT89C51SND1C的MP3播放系统的设计方案。单片机集成了专用的解码器，使用K9F1208闪存作为外存储器，放音电路采用CS4330，存储文件通过播放器上的USB接口设备从PC机上直接下载，液晶显示采用LCD1602。方案设计简单，性价比高，低功耗，易扩展。由于采用的是通用单片机实现的，可以很容易地移植到其他微控制器系统中，有很强的市场竞争能力和实用价值。 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.
上传时间： 2014-12-27
上传用户：佳期如梦
基于AT89C52单片机的步进电机控制系统设计 摘 要: 提出了一个由AT89C52单片机控制步进电机的实例。可以通过键盘输入相关数据, 并根据需要, 实时对步进电机工作方式进行设置, 具有实时性和交互性的特点。该系统可应用于步进电机控制的大多数场合。实践表明, 系统性能优于传统的步进电机控制器。 关键词: 单片机; 步进电动机; 直流固态继电器; 实时控制 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.
上传时间： 2013-11-22
上传用户：vodssv
