Once relegated to the hinterlands of low cost indicatorlights, the LED is again in the spotlight of the lightingworld. LED lighting is now ubiquitous, from car headlightsto USB-powered lava lamps. Car headlights exemplifyapplications that capitalize on the LED’s clear advantages—unwavering high quality light output, tough-assteelrobustness, inherent high effi ciency—while a USBlava lamp exemplifi es applications where only LEDs work.Despite these clear advantages, their requirement forregulated voltage and current Make LED driver circuitsmore complex than the venerable light bulb, but some newdevices are closing the gap. For instance, the LTM®8040μModule™ LED driver integrates all the driver circuitryinto a single package, allowing designers to refocus theirtime and effort on the details of lighting design criticalto a product’s success.
上传时间： 2013-10-16
上传用户：togetsomething
Abstract: As electronic systems take over many of the mechanical functions in a car—ranging from engine timing to steering andbraking—there is a growing concern about fault tolerance. There should not be a single point of failure that would prevent a car fromat least "limping" off the road or making it to the nearest service station. Redundant systems, watchdog timers, and other controlcircuits are used to reroute signals and perform other functions that ensure that a vehicle can safely Make it off the road when afailure occurs.
上传时间： 2013-11-10
上传用户：diets
为解决直流逆变交流的问题，有效地利用能源，让电源输出最大功率，设计了高性能的基于IR2101最大功率跟踪逆变器，并以SPMC75F2413A单片机作为主控制器。高电压、高速功率的MOSFET或IGBT驱动器IR2101采用高度集成的电平转换技术，同时上管采用外部自举电容上电，能够稳定高效地驱动MOS管。该逆变器可以实现DC/AC的转换，最大功率点的跟踪等功能。实际测试结果表明，该逆变器系统具有跟踪能力强，稳定性高，反应灵敏等特点，该逆变器不仅可应用于普通的电源逆变系统，而且可应用于光伏并网发电的逆变系统，具有广泛的市场前景。 Abstract: To solve the problem of DC-AC inverter， and to utilize solar energy more efficiently， the design of maximum power point tracking inverter based on IR2101 was achieved with a high-performance， which can Make the system output power maximum. SPMC75F2413A was adopted as main controller. IR2101 is a high voltage， high speed power MOSFET and IGBT driver. It adopted highly integrated voltage level transforming technology， and an external bootstrap capacitor was used， which could drive MOS tube efficiently and stably. Many functions are achieved in the system， such as DC/AC conversion， maximun power point tracking， etc. The actual test result shows that the inverter system has characteristics of strong tracking ability， high stability and reacting quickly. The design can not only be used in ordinary power inverter system， but also be used in photovoltaic power inverter system. The design has certain marketing prospects
上传时间： 2013-11-17
上传用户：lliuhhui
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标签： 数字电源
上传时间： 2013-10-16
上传用户：dddddd
利用单片机具有的智能程序控制的特点，设计了基于STC89C52单片机的"二极管特性测试器"，可对二极管一般特性进行快速测试。通过稳定线性电流源给二极管加载恒定电流，然后由高精度模数转换器测试其压降，以此为基础可判断二极管好坏、检测二极管极性和测试二极管伏安特性等，避免了用万用表测试只能测得极性而不知其特性这一缺点。可用于电子设计制作过程中对二极管进行快速测试，以确定被测二极管是否满足电路的设计要求。 Abstract: By making good use of the intelligent control function of the Micro Controller Unit (MCU)， the diode trait tester was designed based on the STC89C52，which could be used to test the trait of a diode rapidly. By loading constant current to diode through the stable linear current source， and measuring the voltage drop of the diode by high-precision analogue-to-digital converter (ADC)， it can judge whether the diode is good or not， distinguish the polarity of the diode， and test the trait that the diode， which can avoid the fault of using a multimeter can only measure the polarity but not the trait. This device can be used to test the trait of a diode quickly，and to Make sure that whether a diode can be used in the electronic design or not.
上传时间： 2013-11-13
上传用户：assef
为了使音频信号分析仪小巧可靠，成本低廉，设计了以2片MSP430F1611单片机为核心的系统。该系统将音频信号送入八阶巴特沃兹低通滤波器，对信号进行限幅放大、衰减、电平位移、缓冲，并利用一单片机负责对前级处理后的模拟信号进行采样，将采集得到的音频信号进行4 096点基2的FFT计算，并对信号加窗函数提高分辨率，另一单片机负责对信号的分析及控制显示设备。此设计精确的测量了音频信号的功率谱、周期性、失真度指标，达到较高的频率分辨率，并能将测量结果通过红外遥控器显示在液晶屏上。 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.
上传时间： 2013-12-11
上传用户：jasonheung
介绍一种多功能音乐播放器，它是以AT89S52单片机为核心，并辅有一些外围器件，采用汇编语言编写程序，实现多功能音乐播放，歌曲自动循环播放和使用琴键自编曲目功能。此外，彩灯显示歌曲节奏，按键跳转到喜爱曲目，液晶显示当前播英文曲目。并给出了系统软硬件设计。 Abstract: It introduces a multifunctional music player,taking AT89S52 single-chip microcomputer as hardware control core and using some peripheral elements.Programmes are compiled in assembly language to act as expected.There are two functional modes in this system.One is to Make the music play automatically and consecutively,the other is to compose new songs through keys.In addition,lights show the pace of music and the English names can be displayed in the liquid crystal screen.With perfect combination of hardware and software,the music player can meet many music lovers’needs for multifunctional music player.And the hardware and software of the system are given.
上传时间： 2013-11-18
上传用户：xiaodu1124
伟福仿真器系统概述 本仿真器系统由仿真主机+仿真头、MULT1A用户板、实验板、开关电源等组成。本系统的特点是： 1．主机+仿真头的组合，通过更换不同型号的仿真头即可对各种不同类型的单片机进行仿真，是一种灵活的多CPU仿真系统。采用主机+POD组合的方式，更换POD，可以对各种CPU进行仿真。本仿真器主机型号为E2000/S，仿真头型号为POD8X5X（可仿真51系列8X5X单片机）。 2．双平台，具有DOS版本和WINDOWS版本，后者功能强大，中/英文界面任选，用户源程序的大小不再有任何限制，支持ASM，c，PLM语言混合编程，具有项目管理功能，为用户的资源共享、课题重组提供强有力的手段。支持点屏显示，用鼠标左键点一下源程序中的某一变量，即可显示该变量的数值。有丰富的窗口显示方式，多方位，动态地显示仿真的各种过程，使用极为便利。本操作系统一经推出，立即被广大用户所喜爱。 3．双工作模式①.软件模拟仿真(不要仿真器也能模拟仿真)。②硬件仿真。 4．双CPU结构，100％不占用户资源。全空间硬件断点，不受任何条件限制，支持地址、数据、外部信号、事件断点、支持实时断点计数、软件运行时间统计。 5．双集成环境编辑、编译、下载、调试全部集中在一个环境下。多种仿真器，多类CPU仿真全部集成在一个环境下。可仿真51系列，196系列，PIC系列，飞利蒲公司的552、LPC764、DALLAS320，华邦438等51增强型CPU。为了跟上形势，现在很多工程师需要面对和掌握不同的项目管理器、编辑器、编译器。他们由不同的厂家开发，相互不兼容，使用不同的界面，学习使用都很吃力。伟福WINDOWS调试软件为您提供了一个全集成环境，统一的界面，包含一个项目管理器，一个功能强大的编辑器，汇编Make、Build和调试工具并提供千个与第三方编译器的接口。由于风格统一，大大节省了您的精力和时间。 6．强大的逻辑分析仪综合调试功能。逻辑分析仪由交互式软件菜单窗口对系统硬件的逻辑或时序进行同步实时采样，并实时在线调试分析，采集深度32K(E2000/L)，最高时基采样频率达20MHz，40路波形，可精确实时反映用户程序运行时的历史时间。系统在使用逻辑分析仪时，除普通的单步运行、键盘断点运行、全速硬件断点运行外，还可实现各种条件组合断点如：数据、地址、外部控制信号、CPU内部控制信号、程序区间断点等。由于逻辑仪可以直接对程序的执行结果进行分析，因此极大地便利于程序的调试。随着科学技术的发展，单片机通讯方面的运用越来越多。在通讯功能的调试时，如果通讯不正常，查找原因是非常耗时和低效的，您很难搞清楚问题到底在什么地方，是波特率不对，是硬件信道有问题，是通讯协仪有问题，是发方出错还是收方出错。有了逻辑仪，情况则完全不一样，用它可以分别或者同时对发送方、接收方的输入或者输出波形进行记录、存储、对比、测量等各种直观的分析，可以将实际输出通讯报文的波形与源程序相比较，可立即发现问题所在，从而极大地方便了调试。 7．强大的追踪器功能追踪功能以总线周期为单位，实时记录仿真过程中CPU发生的总线事件，其触发条件方式同逻辑分析仪。追踪窗口在仿真停止时可收集显示追踪的CPU指令记忆信息，可以以总线反汇编码模式、源程序模式对应显示追踪结果。屏幕窗口显示波形图最多追踪记忆指令32K并通过仿真器的断点、单步、全速运行或各种条件组合断点来完成追踪功能。总线跟踪可以跟踪程序的运行轨迹。可以统计软件运行时间。
上传时间： 2013-11-01
上传用户：xiehao13
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
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
