The above title is not happenstance and was arrived at afterconsiderable deliberation. As a linear IC manufacturer, it isour goal to encourage users to design and build switchingregulators. A problem is that while everyone agrees thatworking switching regulators are a good thing, everyonealso agrees that they are difficult to get working. Switchingregulators, with their high efficiency and small size, areincreasingly desirable as overall package sizes shrink.Unfortunately, switching regulators are also one of themost difficult linear circuits to design. Mysterious modes,sudden, seemingly inexplicable failures, peculiar regulationcharacteristics and just plain explosions are commonoccurrences. Diodes conduct the wrong way. Things gethot that shouldn’t. Capacitors act like resistors, fusesdon’t blow and transistors do. The output is at ground, andthe ground terminal shows volts of noise.
标签： Regulators Switching Poets for
上传时间： 2013-12-19
上传用户：奇奇奔奔
Most portable computers have built-in sockets to acceptsmall PC cards for use as extended memories, fax modems,network interfaces, wireless communicators and awide assortment of other functions. The Personal ComputerMemory Card International Association (PCMCIA)has released specifications that outline the general powerrequirements for these cards.
上传时间： 2013-11-18
上传用户：bcjtao
为了改变目前电网现场作业管理的变电巡检、变电检修试验、输电线路巡检检修等管理系统各自独立运行，信息不能共享，功能、效率受限，建设和维护成本高的现状，提出了采用B/S+C/S构架模式，将各现场作业管理模块和生产MIS（管理系统）集成为一体的现场作业管理系统的设计方案，做到各子系统和生产MIS软硬资源共享，做到同一数据唯一入口、一处录入多处使用。各子系统设备人员等基础信息来源于生产管理系统，各子系统又是生产管理系统的作业数据、缺陷信息的重要来源。经过研究试用成功和推广应用，目前该系统已在江西电网220 kV及以上变电站全面应用。 Abstract: In order to improve the status that the substation field inspection system， substation equipments maintenance and testing system， power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency， and their construction and maintenance costs are high. This paper introduces a field standardized work management system based on B/S+C/S mode， integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS，the field work data of the sub systems are the source information of MIS， by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing， this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
上传时间： 2013-11-15
上传用户：han_zh
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
The latest generation of Texas Instruments (TI) boardmountedpower modules utilizes a pin interconnect technologythat improves surface-mount manufacturability.These modules are produced as a double-sided surfacemount(DSSMT) subassembly, yielding a case-less constructionwith subcomponents located on both sides of theprinted circuit board (PCB). Products produced in theDSSMT outline use the latest high-efficiency topologiesand magnetic-component packaging. This providescustomers with a high-efficiency, ready-to-use switchingpower module in a compact, space-saving package. Bothnonisolated point-of-load (POL) switching regulators andthe isolated dc/dc converter modules are being producedin the DSSMT outline.TI’s plug-in power product line offers power modules inboth through-hole and surface-mount packages. The surfacemountmodules produced in the DSSMT outline use asolid copper interconnect with an integral solder ball fortheir
上传时间： 2013-10-10
上传用户：1184599859
大家知道，气体放电灯（日光灯﹑高压钠灯﹑高压汞灯，金属卤化物灯等）传统上采用电感式镇流器（Ballast）和灯管串接起来，接入电网电压，另外单独采用启辉器或触发器，以产生必要的高压（超前顶峰式镇流器无需触发器）使灯点亮。当灯点亮后，利用电感镇流器自身的阻抗来控制或限制灯管电流，使灯管稳定工作。这种电感镇流器，一般是采用硅钢片堆栈起来作铁心，缠绕漆包线制作成。工作频率一般是50 Hz/60Hz。这种镇流器相对体积大﹑笨重，且功耗大、效率低。 为了克服电感镇流器的缺点，人们设法提高灯的工作频率。这是因为，工作频率提高一倍，镇流器的体积就缩小到原来的0.707。现在流行起来的电子节能灯，其电子镇流器都是通过AC/DC/AC变换，把市电50 Hz/60 Hz 交流电压，先变成直流电压，再通过逆变器变成几十kHz 的交流电压，从而用铁氧体磁芯取代了硅钢片，实现了电子镇流器的轻量化，产生了一体化电子节能灯，并使其功耗降低，光效提高。 但是，对于高强度气体放电（High Intensity Discharge缩写HID）灯（高压钠灯，高压汞灯，金属卤化物灯等），特别是金属卤化物灯（金卤灯）其工作频率升高（一般升高到800 Hz 以上），灯电弧容易产生声共振现象。其表现为灯电弧发生扭曲，有时呈月芽形，有时摆动不稳定，使灯光闪烁，严重时会引起电弧管损坏发生爆裂。 于是，人们想出了许多办法，也产生了许多专利技术。这些办法或者用来防止声共振的发生，或者用来减弱、抑制声共振的发生。这些办法一般都采用了最新的电子技术、集成电路和控制技术，技术难度大，造价高。
上传时间： 2014-03-24
上传用户：jelenecheung
Features: High efficiency, high reliability, low cost AC input range selected by switch 100% full load burn-in test Protections: Short circuit / Over load Fixed switching frequency at 25KHz Cooling by free air convection 1 year warranty Dimensions: 199*98*38mm (L*W*H)
标签： Switchin Output Single SKS
上传时间： 2013-10-30
上传用户：taa123456
The P89LPC912/913/914 are single-chip microcontrollers in low-cost 14-pin packages, based on a high performance processor architecture that executes instructions in two to four clocks, six times the rate of standard 80C51 devices. Many system level functions have been incorporated into the P89LPC912/913/914 in order to reduce component count, board space, and system cost.
上传时间： 2013-10-12
上传用户：司令部正军级
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
HIGH SPEED 8051 μC CORE - Pipe-lined Instruction Architecture; Executes 70% of Instructions in 1 or 2 System Clocks - Up to 25MIPS Throughput with 25MHz System Clock - 22 Vectored Interrupt Sources MEMORY - 4352 Bytes Internal Data RAM (256 + 4k) - 64k Bytes In-System Programmable FLASH Program Memory - External Parallel Data Memory Interface – up to 5Mbytes/sec DIGITAL PERIPHERALS - 64 Port I/O; All are 5V tolerant - Hardware SMBusTM (I2CTM Compatible), SPITM, and Two UART Serial Ports Available Concurrently - Programmable 16-bit Counter/Timer Array with 5 Capture/Compare Modules - 5 General Purpose 16-bit Counter/Timers - Dedicated Watch-Dog Timer; Bi-directional Reset CLOCK SOURCES - Internal Programmable Oscillator: 2-to-16MHz - External Oscillator: Crystal, RC, C, or Clock - Real-Time Clock Mode using Timer 3 or PCA SUPPLY VOLTAGE ........................ 2.7V to 3.6V - Typical Operating Current: 10mA @ 25MHz - Multiple Power Saving Sleep and Shutdown Modes 100-Pin TQFP (64-Pin Version Available) Temperature Range: –40°C to +85°C
标签： C8051F020
上传时间： 2013-10-12
上传用户：lalalal
