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
As logic systems get larger and more complex, theirsupply current requirements continue to rise. Systemsrequiring 100A are fairly common. A high current powersupply to meet such requirements usually requires parallelingseveral power regulators to alleviate the thermalstress on the individual power components. A powersupply designer is left with the choice of how to drive theseparalleled regulators: brute-force single-phase or smartPolyPhaseTM.
上传时间： 2013-10-08
上传用户：zhqzal1014
光伏发电是未来新能源发电重要方向之一，而光伏变流器是光伏发电系统的核心。介绍一种基于微网理念的光伏变流器设计。以该变流器为核心的光伏发电系统可以看做一个小型的微网系统。该系统能根据外部电网情况，工作于并网模式和离网模式。介绍了该系统的各个组成部件的设计以及变流器主电路部分器件的选型。最后，由实验样机进行测试。试验结果验证了电路拓扑结构及控制方案的可行性，也说明了系统参数设计方法的正确性。 Abstract: Solar Photovoltaic generation is an important direction of new energy power generation in the future，while photovoltaic converter is the core of photovoltaic generation system. This paper deals with a study on photovoltaic inverter based on the concept of microgrid. This paper describes a system whose core component is the photovoltaic inverter，can work on grid-connected mode or run independently according to the external situation. The paper simply describes the main components of the system. At last，the prototype was produced and tested. Test result has proved feasibility of circuit topology structure and controlling scheme and shown correctness of system parameters.Key words: PV inverter； microgrid； off-grid； storage battery
上传时间： 2014-12-24
上传用户：Shaikh
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标签： 数字电源
上传时间： 2013-10-16
上传用户：dddddd
Abstract: This application note describes how to build, debug, and run applications on the on-board MAXQ622microcontroller to interface with the DS8005 dual smart card interface. This is demonstrated in both IAREmbedded Workbench and the Rowley CrossWorks IDE, using sample code provided with the kit.
上传时间： 2013-10-29
上传用户：ddddddd
数字控制的交流调速系统所选用的微处理器、功率器件及产生PWM波的方法是影响交流调速系统性能好坏的直接因素。在介绍了正弦脉宽调制(SPWM)技术的基础上，设计了一种以8098单片机作为控制器，以智能功率模块IPM为开关器件的变频调速系统。通过软件编程，产生正弦脉冲宽度调制波形来控制绝缘栅双极晶体管的导通和关断，从而达到控制异步电动机转速的目的。实验结果表明，该系统可调频率调电压，稳定度高，调速范围宽，具有较强的实用价值 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.
上传时间： 2013-11-14
上传用户：ynwbosss
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
针对科研实验中对拉压千斤顶加载过程控制的需要，采用ATmega128单片机控制步进电机进而实现对执行系统的电动泵站实行自动控制。对力和位移的数据采集与处理及用步进电机控制电动泵站手柄的技术细节作了重点描述。通过单片机的A/D变换器对AMP放大模块采集的电桥信号作量化处理，千斤顶的操控手柄位置依电动油泵阀门开启的方向和大小作若干定位，单片机根据力或位移传感器信号，实时控制步进电机驱动手柄旋转到相应操控位置。 Abstract: This article describes the use of ATmega128 AVR microcontroller series of DBS electric pumping stations and QF100/200 separate twoway hydraulic jack to automate the process of manipulating the work of the technical content. Articles on force and displacement data acquisition and processing， and stepper motor control electric pump with the handle of the key technical details were described. Through the MCU’s A / D converter module is collected on the AMP amplification quantify the signal bridge， jack handle position control valve opening according to the direction of electric pumps for a number of positioning and size of the microcontroller based on force or displacement sensor signals， real-time control stepper motor drive control handle rotate to the appropriate location.
上传时间： 2014-01-16
上传用户：hasan2015
为解决电致变色器件的颜色变化受外界环境颜色控制的问题，设计了一种基于单片机的便携式颜色自适应识别电路。与传统颜色识别电路相比较，该电路利用数字式的颜色传感器来获取外界环境颜色，产生的数字颜色信号易于单片机进行处理。在电路中，下位机部分主要负责获取电致变色器件变色参数及控制电致变色器件的颜色变化;而上位机部分主要负责把下位机获取的电致变色器件变色参数进行电压到颜色的曲线拟合，并通过蓝牙通信把拟合曲线参数传递给下位机。结果表明，该电路能自动根据环境颜色提供-4~4 V范围步进为0.1 V的电压来驱动电致变色器件的颜色显示，与传统的颜色识别电路设计相比，识别的精度和速度都得到了明显改善。 Abstract: In this paper， a portable adaptive circuit for color identification(PACCI) based on MCU was designed. Compared to the traditional color identification circuit， the PACCI adopts digital sensor to detect the color data from external environment and further generate digital color data， which can be processed easily by MCU. In PACCI， the slave is mainly responsible for detecting the color parameters of the corresponding elcreochromic device and further driving it. For the master， which is mainly responsible for the color curve fitting based on the parameters of the electrochromic device， and transmits the fitting parameters to the slave through the bluetooth device. The results show that the PACCI can provide the basis voltage range from -4V to 4V automatically based on the colors of external environment with step as 0.1V to drive the corresponding electrochromic device. Compared to the traditional color recognition circuit， the recognition accuracy and speed of PACCI have been improved significantly.
上传时间： 2013-11-09
上传用户：franktu
现有基于MAX7219芯片的数码管驱动电路只适用于小尺寸LED，为扩展其使用范围，在介绍动态显示芯片MAX7219功能的基础上，提出了一个基于该芯片的8位高亮度8英寸数码管驱动电路。电路保留了MAX7219芯片的功能强大、编程简单等优点，通过74LS273锁存器和ULN2803达林顿驱动器，实现了对任意大尺寸数码管提供较高电压和电流驱动的静态显示，并亮度可调。 Abstract: The existing display-driving circuit based on MAX7219 was only applicable to small-size LED. To expand its use, based on the function introduction of dynamic display chip MAX7219, a display-driving circuit for high-brightness 8-bit LED with the size of 8-inch was proposed. The advantages of MAX7219 were retained, such as powerful function and simple programming. Static display with adjustable brightness for large-size LED with higher voltage and current was achieved with the help of 74LS273 and ULN2803.
上传时间： 2013-10-23
上传用户：31633073
