This ink marks LTC’s eighth circuit collection publication.1We are continually surprised, to the point of near mystification, by these circuit amalgams seemingly limitlessappeal. Reader requests ascend rapidly upon publication,remaining high for years, even decades. All LTC circuitcollections, despite diverse content, share this popularity,although just why remains an open question. Why isit? Perhaps the form; compact, complete, succinct andinsular. Perhaps the freedom of selection without commitment,akin to window shopping.
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.
為了改變目前電網(wǎng)現(xiàn)場作業(yè)管理的變電巡檢、變電檢修試驗、輸電線路巡檢檢修等管理系統(tǒng)各自獨立運行，信息不能共享，功能、效率受限，建設和維護成本高的現(xiàn)狀，提出了采用B/S+C/S構架模式，將各現(xiàn)場作業(yè)管理模塊和生產(chǎn)MIS（管理系統(tǒng)）集成為一體的現(xiàn)場作業(yè)管理系統(tǒng)的設計方案，做到各子系統(tǒng)和生產(chǎn)MIS軟硬資源共享，做到同一數(shù)據(jù)唯一入口、一處錄入多處使用。各子系統(tǒng)設備人員等基礎信息來源于生產(chǎn)管理系統(tǒng)，各子系統(tǒng)又是生產(chǎn)管理系統(tǒng)的作業(yè)數(shù)據(jù)、缺陷信息的重要來源。經(jīng)過研究試用成功和推廣應用，目前該系統(tǒng)已在江西電網(wǎng)220 kV及以上變電站全面應用。
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.
為解決直流逆變交流的問題，有效地利用能源，讓電源輸出最大功率，設計了高性能的基于IR2101最大功率跟蹤逆變器，并以SPMC75F2413A單片機作為主控制器。高電壓、高速功率的MOSFET或IGBT驅動器IR2101采用高度集成的電平轉換技術，同時上管采用外部自舉電容上電，能夠穩(wěn)定高效地驅動MOS管。該逆變器可以實現(xiàn)DC/AC的轉換，最大功率點的跟蹤等功能。實際測試結果表明，該逆變器系統(tǒng)具有跟蹤能力強，穩(wěn)定性高，反應靈敏等特點，該逆變器不僅可應用于普通的電源逆變系統(tǒng)，而且可應用于光伏并網(wǎng)發(fā)電的逆變系統(tǒng)，具有廣泛的市場前景。
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
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
畢業(yè)設計 USB TO Gigabit LAN 網(wǎng)卡 隨著網(wǎng)絡技術飛速發(fā)展，多媒體的應用越來越多，人們對網(wǎng)絡的要求也越來越高，為了適應市場的需求，網(wǎng)卡出現(xiàn)了。它以其結構簡單、成本低廉、兼容性強等諸多的優(yōu)越性得到了廣泛的應用。由于網(wǎng)絡的應用越來越廣泛，網(wǎng)卡的應用也越來越多、功能越來越強大。開始時由于技術方面的限制，網(wǎng)卡只有10Mbps的吞吐量，由于網(wǎng)絡技術的發(fā)展，100Mbps吞吐量的網(wǎng)卡開始在市場上得到廣泛的應用。而現(xiàn)在1000Mbps吞吐量的網(wǎng)卡的出現(xiàn)又給網(wǎng)絡的傳輸帶來了新的活力。 論文中主要闡述了基于以太網(wǎng)的USB TO Gigabit LAN網(wǎng)卡的設計與制作。論文首先對以太網(wǎng)進行了介紹，緊接著講了網(wǎng)卡的基本知識。隨后又對USB TO Gigabit LAN網(wǎng)卡的電路設計和制作進行了詳細的描述。論文還包括了USB TO Gigabit LAN網(wǎng)卡的調(diào)試等內(nèi)容。
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.
數(shù)字控制的交流調(diào)速系統(tǒng)所選用的微處理器、功率器件及產(chǎn)生PWM波的方法是影響交流調(diào)速系統(tǒng)性能好壞的直接因素。在介紹了正弦脈寬調(diào)制(SPWM)技術的基礎上，設計了一種以8098單片機作為控制器，以智能功率模塊IPM為開關器件的變頻調(diào)速系統(tǒng)。通過軟件編程，產(chǎn)生正弦脈沖寬度調(diào)制波形來控制絕緣柵雙極晶體管的導通和關斷，從而達到控制異步電動機轉速的目的。實驗結果表明，該系統(tǒng)可調(diào)頻率調(diào)電壓，穩(wěn)定度高，調(diào)速范圍寬，具有較強的實用價值
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.
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
利用單片機具有的智能程序控制的特點，設計了基于STC89C52單片機的"二極管特性測試器"，可對二極管一般特性進行快速測試。通過穩(wěn)定線性電流源給二極管加載恒定電流，然后由高精度模數(shù)轉換器測試其壓降，以此為基礎可判斷二極管好壞、檢測二極管極性和測試二極管伏安特性等，避免了用萬用表測試只能測得極性而不知其特性這一缺點。可用于電子設計制作過程中對二極管進行快速測試，以確定被測二極管是否滿足電路的設計要求。
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.
