自动化英语电子教案.docx

1、自动化英语电子教案Unit 1 ElectronicsElements and LawsResistors, Capacitors and Inductors Resistors, capacitors and inductors are very important elements in electronic circuits.Resistors and Resistance A resistor is a two-terminal element. Resistance is the capacity of materials to impede the flow of current

2、or, more specifically, the flow of electric charge. resistor n. 电 电阻器 capacitor n. (=capacitator) 电容器inductor n. 电感器 element n. 元件electronic a. 电子的 circuit n. 电路resistance n. 电阻，阻抗 terminal n. 终端capacity n. 容量 impede v. 阻止current n. 电流 charge n. 负荷，电荷，充电电阻器、电容器和电感器 在电子电路中，电阻器、电容器和电感器是非常重要的元件。电阻器和电阻

3、电阻器是二端口元件。电阻是阻止电流流动，更确切地说，是阻止电荷流动的能力。In SI, resistance is measured in ohms. The Greek letter omega () is the standard symbol for an ohm. Larger amount of resistance are commonly expressed in kilo-ohm (k) and in mega-ohm (M).SI 国际单位制,英文:International System of Units ohm n. 物 欧姆在国际单位制中，电阻用欧姆来度量。希腊字母是欧

4、姆的标准符号。较大的电阻一般用千欧和兆欧来表示。 The circuit element used to model this behavior is the resistor. Figure 1.1 shows the circuit symbol for the resistor, with R denoting the resistance value of the resistor. Figure 1.1 The circuit symbol for a resistor 模拟这种特性常用的电路元件是电阻器。图1.1表示电阻器的电路符号，R表示电阻器的电阻值。图 1.1 电阻器的电路符

5、号 For purposes of circuit analysis, we must reference the current in the resistor to the terminal voltage. If we choose the associated reference direction, the relationship between the voltage and current isv=iR (1.1) Where v is the voltage in volts, i is the current in amperes, and R is the resista

6、nce in ohms.voltage n. 电工 电压， 伏特数associated a. 联合的， 关联的ampere n. 安培为了进行电路分析，我们必须在电阻器中指明电流和电压的参考方向。如果我们选择关联参考方向，那么电压和电流之间的关系是：这里 v 是电压，其单位是伏特， i 是电流，其单位是安培， R 是电阻，其单位是欧姆。If we choose non-associated reference direction, we must write v = -iR (1.2) The algebraic signs used in Eqs (1.1) and (1.2) are kn

7、own as Ohms Law. Ohms Law expressed the voltage as a function of the current. However expressing the current as a function of the voltage is also convenient. Ohms Law is the algebraic relationship between voltage and current for a resistor. non-associated a. 非联合的，非关联的algebraic a. 代数的，关于代数学的Eq. 公式(eq

8、uation)的缩写Ohms Law 欧姆定律function n. 数 函数如果选择非关联参考方向，我们必须写成： v=-iR (1.2)用在公式（1.1）和（1.2）中的代数式就是著名的欧姆定律。欧姆定律表示了电压作为电流的函数。然而，要表示电流是电压的函数也是非常方便的。欧姆定律是电阻两端的电压和电流间的代数关系。Capacitors and Capacitance The device capable of doing this is called a capacitor. The ability of a capacitor to store electrical energy is

9、 termed capacitance.1 Electrical energy can be stored in an electric field. Figure 1.2 shows the circuit symbol for the capacitor. capacitance n. 容量，电容electric field 电场电容器和电容电能可以存储在电场中，存储电能的装置叫电容器。电容器存储电能的能力叫做电容。图1.2表示电容器的电路符号。存储能量的装置叫电容器电容器存储电能的能力叫做电容句中“to store electrical energy”为不定式作定语两个句子都是被动语态,

10、在科技英语中经常使用被动语态The circuit parameter of capacitance is represented by the letter C, is measured in farads (F). Because the farad is an extremely large quantity of capacitance practical capacitor values usually lie in the picofarad (pF) to microfarad (F) range. Fig.1.2 The circuit symbol for a capacit

11、or parameter n. 参数，参量 faradfarad n. 电 法拉，电容单位 picofarad n. 电 皮(可), 法拉, 微微法拉, 百亿分之一法拉, 符号为PF或pf microfarad n. 电 微法拉电容的电路参数用字母C表示，用法拉来度量。因为法拉是相当大的电容量，实际上电容值通常位于皮法和微法之间。图.1.2 电容器的电路符号As the voltage varies with time, the displacement of charge also varies with time, causing what is known as the displace

12、ment current.2 At the terminals, the displacement current is indistinguishable from a conduction current. When the current reference and the voltage reference are associated, the current is proportional to the rate at which the voltage across the capacitor varies with time, or, mathematically, where

13、 i is measured in amperes, C in farads, v in volts, and t in seconds.当电压随时间变化时,电荷的位移也随时间变化,引起了众所周知的位移电流在“causing what .”中,causing是现在分词短语作结果状语,what引导宾语从句,作causing的宾语 当电压随时间变化时，电荷的位移也随时间变化，引起了众所周知的位移电流。在终端，位移电流和传导电流没有区别。当电流参考方向和电压参考方向是关联参考方向时，电流正比于电容两端电压随时间的变化率，数学表达式为：这里 i的单位是安培，C的单位是法拉，v的单位是伏特， t的单位是

14、秒。 Inductors and Inductance It is well known that inductors are one of building blocks in electronic circuits. All coils have inductance. Inductance is the property of opposing any change of a current flowing through a coil. Inductance is symbolized by the letter L, is measured in henrys (H). Figure

15、 1.3 shows an inductor. Fig.1.3 The circuit symbol for an inductorinductance n. 感应系数，自感应coil v. 盘绕,卷,线圈henry n. henries 亨利(电感单位)电感器和电感 众所周知，电感是电子电路中的模块之一。所有的线圈都有电感。电感是抵抗流过线圈电流的任何变化的性质。电感用字母L表示，其单位是亨利。 图1.3表示一个电感器。 图1.3 电感器的电路符号When the reference directions of the current and voltage are associated,

16、yields where v is measured in volts, L in henrys, i in amperes, and t in seconds. 当电流和电压的参考方向关联时，有(1.4) 这里 v 的单位是伏特，L 的单位是亨利， i 的单位是安培， t 的单位是秒。 Note from Eq. (1.4) that the voltage across the terminals of an inductor is proportional to the time rate of change of the current in the inductor. We can

17、make two important observations here. First, if the current is constant, the voltage across the ideal inductor is zero. Thus the inductor behaves as a short circuit in the presence of a constant, or dc. current. Second, a current cannot change instantaneously in an inductor, that is, the current can

18、not change by a finite amount in zero time. An inductor, like a capacitor, stores the energy supplied to it, but it stores energy in the form of a magnetic rather than an electric field.3constant n. 数物 常数，恒量finite a. 有限的，数有穷的， 限定的short circuit 短路dc. current 直流电流电感器和电容器一样,存储供给它的能量,但是它是以磁场的形式而不是以电场的形式

19、存储能量句中“rather than”可作连词词组使用,连接两个并列成分,表示在两者中间进行选择,否定后者后面可以接名词代词形容词副词动词和动词不定式等 Exercises1. two-terminal element 2. associated reference direction Ohms Law 4. electric field . Choose one word from the word list below to fill in the blank in each of the following sentences. Change the form of the word w

20、here necessary.1. The ability of a capacitor to store electrical energy is termed .2. A is a device designed to have capacitance.3. In SI is measured in ohms.4. Ohms Law is the algebraic relationship between the voltage and current for a .5. is the property of opposing any change of a current flowin

21、g through a coil.6. stores energy in the form of a magnetic rather than an electric field.III. Please translate the following paragraph into Chinese.We can make two important observations here. First, if the current is constant, the voltage across the ideal inductor is zero. Thus the inductor behave

22、s as a short circuit in the presence of a constant, or dc. current. Second, a current cannot change instantaneously in an inductor, that is, the current cannot change by a finite amount in zero time. 在此，我们可以得到两条重要的结论：第一，如果电流是常数，理想电感器的端电压为0，这样电感器在恒量或直流中可以当作短路；第二，在电感器中电流不能瞬时变化，也就是说，在0时间内电流不能以有限量改变。科技英

23、语的翻译标准及方法 翻译是一种语言表达法,是译者根据原作者的思想,用本国语言表达出来这就要求译者必须确切理解和掌握原著的内容和意思,丝毫不可以离开它而主观地发挥译者个人的想法和推测在确切理解的基础上,译者必须很好地运用本国语言把原文通顺而流畅地表达出来 1. 翻译的标准 科技英语的翻译标准可概括为“忠实通顺”四个字 忠实:首先指忠实于原文的内容,译者必须把原作的内容完整而准确地表达出来,不得任意增删歪曲;忠实还指保持原作风格,尽可能还其本来面目 通顺:指译文语言必须通顺易懂,符合汉语规范忠实与通顺是相辅相成的忠实而不通顺,读者看不懂,也就做不到忠实;通顺而不忠实,脱离原作的内容与风格,通顺也就

24、失去了作用例如: 1) He knows something about electricity. 错误译法:他知道有关电的某些东西正确译法:他懂点电 2) The electric resistance is measured in ohms. 错误译法:电的反抗是用欧姆测量的。正确译法:电阻的测量单位是欧姆 3) All metals do not conduct electricity equally well. 错误译法:全部金属不导电得相等好。正确译法:并非所有的金属都同样好地导电4) The moment the circuit is completed,a current wil

25、l start flowing toward the coil. 错误译法:电路被完成的片刻,一个电流将开始流向这个线圈正确译法:电路一接通,电流就开始流向线圈从以上例句中可以清楚地看到:不要任意增删,并非是逐词死译;译文汉语规范化,并非是离开原文自由发挥 在科技英语的翻译过程中,还应该注意通用术语的译法例如,例句2中“电阻”是术语,没有别的译法 2. 翻译的方法 翻译的方法大体说来有两种:直译(literal translation)和意译(free translation) 直译,即指“既忠实于原文内容,又忠实于原文形式”的翻译,但决不是“死译”,不可望文生义 意译,就是指忠实于原文的内容

26、,不拘泥于原文的形式 在翻译时,我们应灵活使用上述两种方法,能直译的就直译,能意译的就意译,因为对同一个句子有时并非只 能用一种方法,有时两种方法可交替使用或同时并用总之,要遵循“忠实通顺”的宗旨 试看下面的例子: the Milky Way银河(意译)(不可直译为:牛奶路) bulls eye靶心(意译)(不可直译为:牛眼睛) catch a cold 感冒(意译)(不可直译为:抓住一个冷) New uses have been found for old metals,and new alloys have been made to satisfy new demands. 老的金属有了新

27、用途,新的合金被冶炼出来,以满足新的需要(本句前半部分用的是意译法,后半部分用的是直译法)The Ideal Basic Circuit Element and Kirchhoffs Laws The ideal basic circuit element An ideal basic circuit element has three attributes: (1) it has only two terminals, which are points of connection to other circuit components: (2) it is described mathema

28、tically in terms of currents and/or voltages, and (3) it cannot be subdivided into other elements. We use the word “ideal” to imply that a basic circuit element does not exist as a realizable physical component. We use the “basic” to imply that the circuit element cannot be further reduced or subdiv

29、ided into other elements. Thus the basic circuit elements form the building blocks for constructing circuit models, but they themselves cannot be modeled with any other type of elements.There are five ideal basic circuit elements: voltage sources, current sources, resistors, inductors, and capacitor

30、s. Kirchhoffs Laws A circuit is said to be solved when the voltage across and the current in every element have been determined. Ohms Law is an important equation for deriving such solutions. In simple circuit structures, Ohms Law is sufficient for solving for the voltages across and the currents in

31、 every element. However, for more complex interconnections we need to use two more important algebraic relationships known as Kirchhoffs Laws, to solve for all the voltages and currents. There are Kirchhoffs Current Law and Kirchhoffs Voltage Law. Kirchhoffs Current Law can be stated, the algebraic sum of all the currents at any node in a circuit equals zero. To use Kirchhoffs Current Law, an algebraic sign corresponding to a reference direction must be assigned to every current at the node. Assigning a positive sign to a current leaving a node requires assigning a negativ