专业英语翻译中英对照.docx

1、专业英语翻译中英对照1. Electrical Measuring Instruments电子测量仪表Electrical personnel use many different types of measuring instruments. 电子技术人员使用许多不同类型的测量仪器。Some jobs require very accurate measurements while other jobs need only rough estimates. 一些工作需要精确测量面另一些工作只需粗略估计。Some instruments are used solely to determine

2、 whether or not a circuit is complete. 有些仪器被使用仅仅是确定线路是否完整。The most common measuring and testing instruments are voltage testers, voltmeters, ammeters, ohmmeters, continuity testers, megohmmeters, wattmeters（功率计）, and watt-hour meters（电度表，电表）。 最常用的测量测试仪表有：电压测试仪，电压表，欧姆表，连续性测试仪，兆欧表，瓦特表还有瓦特小时表。All meter

3、s used for measuring electrical values are basically current meters. 所有测量电值的表基本上都是电流表。They measure or compare the values of current flowing through them. 他们测量或是比较通过他们的电流值。The meters are calibrated and the scale is designed to read the value of the desired unit. 这些仪表可以被校准并且设计了不同的量程，以便读出期望的数值。1.1 SAFE

4、TY PRECAUTION安全预防Correct meter connections are very important for the safety precaution of the user and for proper maintenance of the meters. 仪表的正确连接对于使用者的安全预防和仪表的正确维护是非常重要的。A basic knowledge of the construction and operation of meters will aid the user in making proper connections and maintaining t

5、hem in safe working order. 仪表的结构和操作的基本知识能帮助使用者按安全工作程序来对他们正确连接和维护。Many instruments are designed to be used on DC or AC only, while others can be used interchangeably. 许多仪表被设计的只能用于直流或只能用于交流，而其它的则可交替使用。Note: It is very important to use each meter only with the type of current for which the meter is des

6、igned. 注意：每种仪表只能用来测量符合设计要求的电流类型。Using a meter with an incorrect type of current can result in damage to the meter and may cause injury to the user. 如果用在不正确的电流类型中可能对仪表有危险并且可能对使用者引起伤害。Some meters are constructed to measure very low values. 许多仪表被设计成只能测量很低的数值Other meters can measure extremely high value

7、s.还有些能测量非常大的数值。CAUTION: Never allow a meter to exceed its rated maximum limit. 警告：仪表不允许超过它的额定最大值。The importance of never allowing the actual value to exceed the maximum value indicated on the meter can not be overemphasized. 不允许被测的实际数值超过仪表最大允许值的要求再强调也不过分。Exceeding maximum values can damage the indic

8、ating needle, interfere with proper calibration, and in some instances may cause the meter to explode, resulting in injury to the user. 超过最大值对指针有伤害，有害于正确校准，并且在某种情况下能引起仪表爆炸造成对作用者的伤害。Some meters are equipped with over correct protection. However, a current many times greater than the instruments desig

9、n limit may still be hazardous. 许多仪表装备了过载保护。然而，通常情况下电流大于仪表设计的限定仍然是危险的。2. Fundamentals of Solid-state Power Device固体功率器件的基本原理In this chapter we focus on solid-state power devices, or power semiconductors, only as they are being used in the power leads or power circuits to three-phase 460 V AC squirre

10、l cage induction motors for either phase (voltage) control or frequency (speed) control. 本章将集中讨论固态功率器件或功率半导体器件，并且只研究它们在采用相控（电压控制）或频率控制（速度控制）的三相交流鼠笼式感应电机的功率电路中的应用。 2.2 SOLID-STATE POWER DEVICES固态功率器件The five major types of power semiconductors used in solid-state AC motor control are: 有五种用于固体交流电机控制中的

11、功率元器件：Diodes二极管Thyristorse.g., silicon-controlled rectifiers (SCRs) 晶闸管（例如：可控硅整流器SCR）Transistors电子晶体管Gate-turn-off thyristors门极可关断晶闸管（GTO）Triacs 双向可控硅SCRs and triacs are commonly used for phase controls. 晶闸管SCR和双向可控硅一般用于相位控制（相控）。Various combinations of diodes, SCRs, transistors, and GTOs are used fo

12、r speed controls. 各种二极管，晶闸管SCR，电子晶体管，门极可关断晶闸管的联合体用于频控。The commonality of these devices is the use of crystals of silicon in the form of wafers that are layered so as to form various combinations of PN junction. 这些器件的共性是：利用硅晶体形成的薄片构成P-N结的各种组合。The P junction is usually called the anode and N junction

13、is usually called the cathode for diodes, SCRs, and GTOs; the corresponding terms for transistors are collector and emitter. 对二极管，SCR， GTO一般P结叫正极N结叫负极；相应的电子晶体管叫集电极和发射极。The differences among these devices relate to how they go into and out of conduction and in their available ampere and voltage capab

14、ilities. 这些器件的区别在于导通和关断的方法及电流和电压的容量。 Lets take a brief look at each of these devices in terms of these parameters. 让我们根据他们的参数简单看一下这些元器件。3 Analog Electronics模拟电子3.1 INTRODUCTION介绍3.1.1 The Contrast between Analog and Digital Electronics模拟和数字电子学对照 We have already explored how transistors and diodes ar

15、e used as switching devices to process information which is represented in digital form. 我们已经研究过三极管和二极管怎样作为开关器件用于处理以数字形式出现的信息。Digital electronics uses transistors as electrically controlled switches: transistors are either saturated or cut off. 数字电子学中，三极管用作电子控制开关：它不是饱和就是截止。The active region is used

16、only in transition from one state to he other.（三极管的）动态区域仅用于从一种状态过渡到另一种状态。 By contrast, analog electronics depends on the active region of transistors and other types of amplifiers. 与之相对的是，模拟电子学依赖于三极管的动态区域和其它放大器的形式。The Greek roots of “analog” mean “in due ratio”, signifying in this usage that informa

17、tion is encoded into an electrical signal which is proportional to the quantity being represented. 希腊语词根“analog”的意思是“以一定的比例”，在这里表示信息被编码成为与表达量成正比的电信号。 In Fig.3.1 our information is some sort of music, originating physically in the excitation and resonances of a musical instrument. 在图3.1中，我们的信息是某种音乐，物

18、理上由乐器的激励和共鸣产生。The radiated sound consists in the ordered movement of air molecules and is best understood ad acoustic waves. 辐射的声波由空气分子的有序运动组成，准确的理解为声波， These produce motion in the diaphragm of a microphone, which in turn produces an electrical signal. 它使话筒的振动膜移动，依次产生电信号。The variation in the electri

19、cal signal are a proportional representation of the sound waves. 电信号的变化与声波成比例。The electrical signal is amplified electronically, with an increase in signal power occurring at the expense of the input AC power to the amplifier. 电信号被用电子的方法放大，即利用输入放大器的交流电能将信号的功率放大。The amplifier output drives a recordin

20、g head and produces a wavy groove on a disk. 放大器的输出驱动一个记录头，并且在一个圆盘上产生起伏的沟槽。If the entire system is good, every acoustic variation of the air will be recorded on the disk and, when the record is played back through a similar system and the signal reradiated ad sound energy be a loudspeaker, the resul

21、ting sound should faithfully reproduce the original music. 如果整个系统正常，每一次声波振动都会记录在圆盘上，并且当该记录通过类似的系统重放，信号以声能的形式从扬声器辐射出来，所产生的声音能忠实地重现原始音乐。 Electronic systems based on analog principles form an important class of electronic devices. 基于模拟原理的电子系统形成了一类重要的电子仪器。Radio and TV broadcasting are common examples of

22、 analog systems, as are many electrical instruments used in monitoring deflection (strain gages, for example), motion (tachometers), and temperature (thermocouples). 收音机和电视机的播放是模拟系统的典型例子，许多仪器也是模拟系统，它们的应用领域包括偏差检测（应变计量器）运动控制（测速仪）和温度测量（热电偶）。Many electrical instruments-voltmeters, ohmmeters, ammeters, a

23、nd oscilloscopes-utilize analog techniques, at least in part. 许多电子仪器电压表、电流计欧姆表、和示波器应用或至少是部分应用了模拟技术。 Analog computers existed before digital computers were developed. 模拟计算机在数字计算机成熟之前就已存在。In an analog computer, the unknowns in a differential equation are modeled with electrical signals. 在模拟计算中，用电信号模拟微

24、分方程的未知量。Such signals are integrated, scaled, and summed electrically to yield solutions with modes effort compared with analytical or numerical techniques. 用电子的方法对这些信号积分、比例运算和求和以获得方程的解，比起解析或数值求解方法要容易一些。4.1.1 What is a Digital Signal什么是数字信号 A Historical Example. 一个历史例子“Listen my children and you shal

25、l hear of the midnight ride of Paul Revere”听，我的孩子们，你们将会听到保罗瑞维尔午夜策马飞奔的传奇，According to Longfellows poem, Paul Revere was sent riding through the New England countryside by a signal from the bell tower of the Old North Church in Boston. 根据朗费罗的诗，保罗瑞维尔通过波士顿老北教堂的钟楼那里给新英格兰农民发信号。（不写：如果英军今晚无论是从陆地还是从海上来犯，在老北教

26、堂钟楼的拱门上高挂一盏灯笼作为信号） “One if by land and two if by sea.”。一盏灯笼表示从陆地来，两盏灯笼表示从海上来。That is, one light was to be displayed if the Britishforces were advancing toward Concord by the road from Boston, and two lightswere to be displayed if they were crossing the Mystic River to take an indirectroute)那就是说， 如果英

27、国军队从波士顿陆地向康科德前进，展示一盏灯，如果他们穿过Mystic河走间接航线，两盏灯将被展示。The message received by the Patriot was coded in digital form. 爱国者们收到的消息就是数字形式的编码。We would say today that the two“bits”of information were conveyed by the code(strictly speaking, two bits could indicate four possible message and would require distingu

28、ishable lights, say one red and one white). 我们今天将说这两个位的信息通过代码运传送(严格地说， 二位能表明4个可能消息，并且要求可分辨的灯，一个红灯和一个白色的灯) .The first light signaled that the British were advancing. 第一个灯光通知英国军队正前进，The second light indicated by what route they were coming. 第2盏灯指示他们通过什么路线来。Because only two routes ofadvance were envisi

29、oned, this second bit of information could be interpreted asindicating one of the two routes. 因为想象只有两条路，信息的第二位能被解释为表明两条路线之一。Information can be communicate in digital form if the massage is capable of being defined by a series of yes/no statements. 如果信息能被一系列的YES/NO所定义，信息就能以数字形式确定。There can be only tw

30、o states of each variable used in conveying the information. 每个变量只可能有两种状态在传送信息方面使用。 Reducing information to a series of yes/no statements might appear to be a severe limitation on this method, but the method is in fact quite powerful. 这种方法把信息简化为一系列是/不看起来有局限性，但是这种方法实际上十分有用。 Numbers can be represented

31、 in base 2 and the alphabet by a digital code. 数目可以以基数2表示，字母表可以表示成数字代码。Indeed, any situation with a finite number of outcomes can be reduced to a digital code. 的确，有限输出的任何情形都可以被简化成数字代码。 Specifically, n digital bits can represent 2n states of possible outcomes. 具体的，n位数字能描述成2n个可能状态。 Digital communicati

32、on takes a well-defined code known to the parties at both ends, as in our historical example. 如同在我们的历史例子中，数字通讯能用明确定义的代码在两种情况下都通知到大家。Analysis of the Revere Communication Code. 瑞维尔通讯码分析。In order to fix further the idea of digital information, we shall define two digital variables which describe the Pa

33、ul Revere communication system, Let B describe whether the British are coming, and L describe the route by which they are coming, provide that they are coming. 为了更进一步确定数字的信息的概念， 我们将定义两个来描述保罗瑞维尔通信系统的数字变量， 让B描述是否英国人正来，并且L描述他们正来的路线。The mathematical variables, B and L, are unusual mathematical variables because each can have