【正文】 自動洗衣機(jī)的控制，以及程控玩具、電子寵物等等，這些都離不開單片機(jī)。因此，單片機(jī)的學(xué)習(xí)、開發(fā)與應(yīng)用將造就一批計(jì)算機(jī)應(yīng)用與智能化控制的科學(xué)家、工程師。采用單片機(jī)控制使得儀器儀表數(shù)字化、智能化、微型化，且功能比起采用電子或數(shù)字電路更加強(qiáng)大。這里面最好的例子便是電子秤了。目前，臺式電了秤在商業(yè)貿(mào)易中的使用已相當(dāng)普遍，但存在較大的局限性：體積大、成本高、需要工頻交流電源供應(yīng)、攜帶不便、應(yīng)用場所受到制約。多年來，人們一直期待測量準(zhǔn)確、價格低廉的在工業(yè)發(fā)展中起到巨大作用的電子秤投放市場。 用單片機(jī)可以構(gòu)成形式多樣的控制系統(tǒng)、數(shù)據(jù)采集系統(tǒng)。 可以這樣說，現(xiàn)在的家用電器基本上都采用了單片機(jī)控制，從電飯煲、洗衣機(jī)、電冰箱、空調(diào)機(jī)、彩電、其他音響視頻器材、再到電子秤量設(shè)備，五花八門，無所不在。 單片機(jī)在醫(yī)用設(shè)備中的用途亦相當(dāng)廣泛，例如醫(yī)用呼吸機(jī)，各種分析儀，監(jiān)護(hù)儀，超聲診斷設(shè)備及病床呼叫系統(tǒng)等等。如音樂集成單片機(jī)，看似簡單的功能，微縮在純電子芯片中（有別于磁帶機(jī)的原理），就需要復(fù)雜的類似于計(jì)算機(jī)的原理。 在大型電路中，這種模塊化應(yīng)用極大地縮小了體積，簡化了電路，降低了損壞、錯誤率，也方便于更換。 此外，單片機(jī)在工商，金融，科研、教育，國防航空航天等領(lǐng)域都有著十分廣泛的用途。一、能量回饋單元工作原理在變頻調(diào)速系統(tǒng)中，當(dāng)電機(jī)的負(fù)載是位能式負(fù)載如：油田抽油機(jī)、礦用提升機(jī)等；或大慣量負(fù)載如：風(fēng)機(jī)、水泥制管、 動平衡機(jī)等；以及軋鋼機(jī)、大型龍門刨床、機(jī)床主軸等需要快速制動類負(fù)載時，電機(jī)都不可避免地存在發(fā)電過程，即電機(jī)轉(zhuǎn)子在外力的拖動或負(fù)載自身轉(zhuǎn)動慣量的維持下，使得電機(jī)的實(shí)際轉(zhuǎn)速大于變頻器輸出的同步轉(zhuǎn)速，電機(jī)所發(fā)出的電能將會儲存在變頻器的直流母線濾波電容中，如果不把這部分能量消耗掉，那么直流母線電壓就會迅速升高，影響變頻器的正常工作。 二、能量回饋單元注意事項(xiàng)、能量回饋單元及與其相連接的設(shè)備內(nèi)部都有危及人身安全的高壓，錯誤的操作或不當(dāng)?shù)陌惭b可能會導(dǎo)致人身財產(chǎn)的損失，因此建議由受過專門訓(xùn)練的人員安裝操作。 、能量回饋單元與變頻器的距離盡可能靠近，最遠(yuǎn)不要超過2米。但是接線時要求能量回饋單元的A、B、C端子必須和變頻器的交流輸入端子R、S、T直接相連，不可以通過任何中間開關(guān)或接觸器，也不可以連接到其他交流回路。 、位于散熱器上的PE保護(hù)地接線螺釘，請連接真正的保護(hù)地，不可以連接電網(wǎng)的零線(中性線)。 三、能量回饋單元適用場合、能量回饋單元應(yīng)用在位能式負(fù)載如：油田抽油機(jī)、礦用提升機(jī)等； 、能量回饋單元適用于大慣量負(fù)載如：風(fēng)機(jī)、水泥制管、動平衡機(jī)、離心機(jī)等； 、能量回饋單元適用于需要快速停車的場合，如軋鋼機(jī)、大型龍門刨床、機(jī)床主軸等， 、能量回饋單元適用于其它電動機(jī)可能工作在再生發(fā)電狀態(tài)的場合。而制動單元需和制動電阻一起使用，將電機(jī)再生發(fā)電的電能消耗在制動電阻上變成熱能浪費(fèi)掉。 摩爾，華潤，Balser，Muhich，JS和東，稀土（1992）?！啊癐EEE計(jì)算機(jī)學(xué)會，第200204頁，附錄B 外文原文In November, 1971, a pany called Intel publicly introduced the world39。revolutionized puter design, the only place to go was down in size that is. The Intel 4004 chip took the integrated circuit down one step further by placing all the parts that made a puter think (. central processing unit, memory, input and output controls) on one small chip. Programming intelligence into inanimate objects had now bee possible.The History of IntelIn 1968,were two unhappy engineers working for the Fairchild Semiconductor Company who decided to quit and create their own pany at a time when many Fairchild employees were leaving to create startups. People like Noyce and Moore were nicknamed the Fairchildren.Bob Noyce typed himself a one page idea of what he wanted to do with his new pany, and that was enough to convince San Francisco venture capitalist Art Rock to back Noyce39。s new venture. Rock raised $ million dollars in less than 2 days.One Chip Does the Work of TwelveIn late 1969, a potential client from Japan called Busi, asked to have twelve custom chips designed. Separate chips for keyboard scanning, display control, printer control and other functions for a Busimanufactured calculator.Intel did not have the manpower for the job but they did have the brainpower to e up with a solution. Intel engineer, Ted Hoff decided that Intel could build one chip to do the work of twelve. Intel and Busi agreed and funded the new programmable, generalpurpose logic chip.Federico Faggin headed the design team along with Ted Hoff and Stan Mazor, who wrote the software for the new chip. Nine months later, a revolution was born. At 1/8th inch wide by 1/6th inch long and consisting of 2,300 MOS (metal oxide semiconductor)ENIAC, which had filled 3,000 cubic feet with 18,000 vacuum tubes.Cleverly, Intel decided to buy back the design and marketing rights to the 4004 from Busi for $60,000. The next year Busi went bankrupt, they never produced a product using the 4004. Intel followed a clever marketing plan to encourage the development of applications for the 4004 chip, leading to its widespread use within months.The Intel 4004 MicroprocessorThe 4004 was the world39。s Ted Hoff felt differently。s 64bit microprocessors are still based on similar designs, and the microprocessor is still the most plex massproduced product ever with more than million transistors performing hundreds of millions of calculations each second numbers that are sure to be outdated fast.The single chip structureThe NVIDIA nForce media and munications processors (MCPs) deliver advanced technologies and unmatched performance to desktop, mobile, and professional systems, and continue the NVIDIA tradition of industryleading platform technology.185。Coupled with the NVIDIA Unified Driver Architecture (UDA), which ensures a stable software image for simplified deployment and upgrades in the enterprise, the featurerich NVIDIA MCP platforms deliver value without promising performance, and enable a new generation of highly efficient and scalable systems:The singlechip NVIDIA architecture provides an inherent performance advantage pared to dualchip implementations of the same functionality. In addition to overall latency reductions, the NVIDIA nForce MCP significantly boosts device throughput. An extremely fast dedicated HyperTransport link lets the NVIDIA MCPs municate with the CPU at up to , which ensures ample system bandwidth. This is especially beneficial when multiple devices are active, or for supporting highbandwidth devices.The NVIDIA singlechip architecture uses micron process technology pared with the micron process used by existing solutions on the market today. This solution offers unmatched integration of features and functionality and results in: Simplified board layouts and more room for onboard features and addon chipsets. Lower power consumption and dissipated heat. Simplified inventory management and cost efficiencies.Builtin NVIDIA RAID technology delivers optimized disk performance through disk striping and fault tolerance through disk mirroring. Select versions of the NVIDIA nForce MCPs incorporate a native Gigabit Ethernet port TCP/IP acceleration. NVIDIA delivers the highest performance networking solution for desktops and workstations. In addition, NVIDIA nForce solutions offer support for the latest graphics processors.The NVIDIA nForce MCPs uphold NVIDIA’s traditions of reliability, stability, and patibility. Adherence to the Company’s standards for engineering excellence continues to ensure the success of a growing base of design partners building systems and solutions with AMD and NVIDIA technology.1