應(yīng)用電子專(zhuān)業(yè)畢業(yè)設(shè)計(jì)英語(yǔ)翻譯--- 線性電路

1、<p>　　畢業(yè)設(shè)計(jì)英語(yǔ)翻譯原文與英語(yǔ)譯文</p><p>　　系別： 電子工程系 </p><p>　　專(zhuān)業(yè)： 應(yīng)用電子技術(shù) </p><p>　　姓名： </p><p>　　學(xué)號(hào)： </p><p>　　指導(dǎo)教師： </p>

2、<p>　　2012 年 6月 8 日 </p><p>　　朱一綸.電子技術(shù)專(zhuān)業(yè)英語(yǔ)，北京：電子工業(yè)出版社，2003-7.</p><p>　　Unit 6 Linear Circuit Analysis</p><p><b>　　6.1 Text</b></p><p>　　1. Kirchhotl&#

3、39;s Current Law ( KCL)</p><p>　　It is a txuisocpreice of the work of the Gerniat physicist (1824-1887）that enables us to analyze at intaconraiction d my number of demerits (voltage sources, txure- sources,

4、aid resistors), as wall as other electronic devices We will refer to ary stch interconnection as adroit or network.</p><p>　　For a given circuit, a connection of two or more dernerts shall be called a rroda

5、We now present the first of Kerchief's two laws, his current law (KCL), which is essentially the law of conservation of electric charge:</p><p>　　At my node of a circuit, at every instant of time, the su

6、m of the currents into the node is equal to the sum of the sum of the currents out of node.</p><p>　　An alternative, but equivalent, form of KCL can be obtained by considering currents directed into a node t

7、o be positive in sense and out of a node to be negative in sense. Under This circumstance,the alternative form of KCL can be stated as follows.</p><p>　　At my node of a circuit, the currents algebraically su

8、m to zero.</p><p>　　2. Kirchhoff's Voltage LaW(KVL)</p><p>　　We now present the second of Kirchholf's laws, the voltage law. To do this, we must introduce the concept of a "loop&quo

9、t;. Starting at my node n in a circuit, we form a loop by traversing through elements and returning to the starting node n,and never encountering any other node more than once.Kirchhoff's voltage law (KVL) is:</p&

10、gt;<p>　　In traversing any loop in my circuit, at every instant of time, the sum of the voltages having one polarity equals the sum of tire voltages having tire opposite polarity.</p><p>　　An alternat

11、ive statement of KVL can be obtained by considering voltages across elements that are traversed from plus to minus to be positive in sense and voltages across elements that are traversed from minus to plus to be negative

12、 in sense (or vice versa). Under this circumstance, KVlhas the follow! rig alternative form.</p><p>　　Around any loop in a circuit, the voltages algebraically sum to zero.</p><p>　　3. Sinusoidal

13、 Circuits</p><p>　　Step and impulse functions ere useful in determining the responses of circuits when they are first turned on“when sudden“irregular chagea occur in the input. This is called transient analy

14、sis However, to see how a circuit responds to a regular or repetitive input-the steady-state analysis-function that is by far the most useful is the sinusoid.</p><p>　　The sinusoid is an extremely importart

15、and ubiquitous function. To begin with the shape of ordinary household voltage is sinusoidal, consumer radio transmissions are either amplitude modulation(AM), in which the amplitude dad nusoid is changed or modulated ac

16、cording some information signal，or frequaicy nndulation(FM), in which the frequency of a sinusoid is modulated.</p><p>　　We havefollowi ng conclusions about the sinusoid:</p><p>　　1) If the inp

17、ut of a linear. Time-invariant circuit is a sinusoid, then the response is sinusoid of the same frequency.</p><p>　　2) Finding the magnitude and phase angle of a sinusoidal steady-state response can be accom

18、plished with either real or complex sinusoids.</p><p>　　3) If the output of a sinusoidal circuit reaches its peak before the input, the circuit is a lead network. Conversely, it isalag network.</p>&l

19、t;p>　　4) Using the concepts of phasor and impedaice, snusudal circuits car be analyzed in the frequency domain in a maim analogous to resistive circuits by using the phaser versions of KCL, KVL,nodal analysis, mesh an

20、alysis and loop analysis.</p><p>　　6.2 Reading Materials</p><p>　　1. Resistors and Ohm's Law</p><p>　　Suppose that some material is connected to the terminals of an idenl voltag

21、e source u(t) as shown in Fig 6.1. Stppose that u(t)=1 V. Thai the declric potential at the top of the material is 1 V abovethe potential at the bottom. Since at dectron has a negative charge, electrons in the material

22、will tend to flow from bottom to top. Theefore, we say that current tends to go from top to bottom through the nateial. Hence, far the given polarity, when u(t) is a positive number, i(t) will be a positiv</p><

23、;p>　　2. Information on Amplitude Modulation (AM)</p><p>　　Less power is required to transmit high frequencies than low frequencies, therefore, it is more efficient m transmit high frequencies containing i

24、nformation over great distances. In amplitude modulation(AM), a constant amplitude radio frequency(RF) carrier wave of, for example, 800kHz is produced. The information m be transmuted, perhaps an audio frequency(AF) of

25、50Hz, is sent to a modulating circuit, where it varies the amplitude of the RP carrier wave. An AM signal as seen on an oscilloscope w</p><p>　　第六單元 線性電路的分析</p><p><b>　　6.1 課文</b>&l

26、t;/p><p>　　1. 基爾霍夫電流定律</p><p>　　德國(guó)物理學(xué)家Gustav Kirchhoff (1824~1887) 得出了基爾霍夫定律，使我們可以用它來(lái)分析任何電路元件(電壓源，電流源和電阻)以及其他電子器件相互連接(構(gòu)成的電路)。我們把這種相互連接稱(chēng)為一個(gè)電路或一個(gè)網(wǎng)絡(luò)。對(duì)一個(gè)給定的電路，兩個(gè)或更多的元件的連接點(diǎn)稱(chēng)為節(jié)點(diǎn)。現(xiàn)在我們給出基爾霍夫兩個(gè)定律中的第一個(gè)，基爾霍夫電

27、流定律，它是根據(jù)電荷守恒的定理給出的:</p><p>　　對(duì)電路的任何一個(gè)節(jié)點(diǎn)，在何一瞬時(shí)流入節(jié)點(diǎn)的電流和總是等于流出節(jié)點(diǎn)的電流和。</p><p>　　如果考慮電流的流向，取流入節(jié)點(diǎn)為正，流出節(jié)點(diǎn)為負(fù)，則基爾霍夫電流定律也可以等價(jià)表達(dá)成對(duì)電路中的任一節(jié)點(diǎn)，電流的代數(shù)和為0。</p><p><b>　　克希荷夫電壓定律</b></p&

28、gt;<p>　　現(xiàn)在給出克希荷夫第二定律，電壓定律。我們先引入“閉合回路”的概念。從電路的任一節(jié)點(diǎn)開(kāi)始，通過(guò)電路中每一個(gè)元件，每個(gè)節(jié)點(diǎn)只能通過(guò)一次，再回到電路的出發(fā)節(jié)點(diǎn)形成一個(gè)閉合回路。克希荷夫電壓定律是：</p><p>　　沿著電路的任一閉合回路，每一瞬時(shí)的正電壓和等于負(fù)電壓和。通過(guò)假定元件兩端的電壓是從正到負(fù)為正電壓，元件兩端的電壓是從負(fù)到正為負(fù)電壓，克希荷夫電壓定律也可以表述成下列形式：&

29、lt;/p><p>　　繞電路中的任一閉合回路，電壓的代數(shù)和等于0。</p><p><b>　　3. 正弦電路</b></p><p>　　在討論電路突然合上或電路的輸入是突變或不規(guī)則的時(shí)候，階躍函數(shù)和脈沖函數(shù)可用來(lái)決定電路的響應(yīng)，這就是暫態(tài)分析過(guò)程。但如果想了解對(duì)一個(gè)規(guī)則或周期性的輸入電路是如何響應(yīng)的即穩(wěn)態(tài)分析，則至今為止最有用的是正弦函數(shù)。&

30、lt;/p><p>　　正弦函數(shù)是特別重要和普遍存在的函數(shù)，因?yàn)槿粘Ｓ秒姷碾妷菏钦业?，消費(fèi)電子設(shè)備用的無(wú)線電傳播或者是調(diào)幅(AM)信號(hào)即一個(gè)正弦電壓的幅度是按照一些信息信號(hào)的規(guī)律改變或稱(chēng)調(diào)制，或者是調(diào)頻(FM)信號(hào)即一個(gè)正弦電壓的頻率被調(diào)制。</p><p>　　對(duì)正弦電，我們有如下結(jié)論:</p><p>　　1) 如果一個(gè)線性，穩(wěn)態(tài)電路的輸入是一個(gè)正弦信號(hào)，則它的響

31、應(yīng)是一個(gè)同樣頻率的正弦信號(hào)。</p><p>　　2) 通過(guò)用實(shí)數(shù)或復(fù)數(shù)求解我們可以求出一個(gè)正弦穩(wěn)態(tài)響應(yīng)的幅值和相位角。</p><p>　　3) 如集一個(gè)正弦電路的輸出響應(yīng)比輸入先到它的峰值，則稱(chēng)此電路是超前網(wǎng)絡(luò)，否則則稱(chēng)為滯后網(wǎng)絡(luò)。</p><p>　　4) 用相位和阻抗的概念，在同一頻域的正弦電路可以采用類(lèi)似于分析阻抗電路的方法用克希荷夫的電流、電壓定律的復(fù)數(shù)

32、形式，節(jié)點(diǎn)電流分析法，網(wǎng)絡(luò)分析法和回路分析法進(jìn)行分析。</p><p><b>　　6.2 閱讀材料</b></p><p><b>　　1.電阻和歐姆定律</b></p><p>　　假設(shè)一些材料連接到一個(gè)理想電壓源u(t) 的兩端(如圖6.1所示)，假設(shè)u(t)=1 V,則材料頂部的電勢(shì)(電位)比材料底部的電勢(shì)高出1V

33、，因?yàn)殡娮邮菐ж?fù)電荷的，在材料中的電流i (t)將從材料的底部流向頂部，即我們說(shuō)電流從材料的頂部通過(guò)材料流向底部。因此，電源極性給定時(shí)，當(dāng)u(t)為正時(shí)，方向如圖中所示的電流為正值，如果u(t)=2 V，同理材料頂部的電勢(shì)(電位)比材料底部的電勢(shì)高出2V，所以電流i(t)仍為正的(當(dāng)材料為“線性”材料時(shí)，電流是原來(lái)的兩倍)。如果產(chǎn)生的電流總是正比于給定電源u(t)的電壓，則材料被稱(chēng)為線性電阻。</p><p>&

34、lt;b>　　2.關(guān)于調(diào)幅</b></p><p>　　傳輸高頻信號(hào)要比傳輸?shù)皖l信號(hào)消耗的功率少，所以遠(yuǎn)距離傳輸包含信息的高頻信號(hào)效率比較高。在幅度調(diào)制(調(diào)幅)時(shí)，產(chǎn)生一個(gè)穩(wěn)幅的射頻(無(wú)線電傳輸頻率)如800kHz的載波信號(hào)，要傳輸?shù)男盘?hào)，也許是1個(gè)50Hz的音頤信號(hào)被輸送到：一個(gè)調(diào)制電路中，通過(guò)調(diào)制電路載波信號(hào)的幅度按音頻信號(hào)的規(guī)律變化。一個(gè)調(diào)幅信號(hào)如在示波器中可看到的有調(diào)制峰值和調(diào)制谷底。射