机电专业英语第2版电子教案Unit 14

Unit 14 Resistor, Capacitor and Inductor

I．Lead-in

Information related to the text

Today we’ll study Unit 14— Resistor, Capacitor and Inductor. They form important elements in electronic circuit. In this unit, we’ll grasp the basic knowledge about three fundamental components in electronics and how they are applied in electronic industry. In supplementary reading material, we’ll study how to use multimeters to measure current, voltage and resistance. Now, let’s study key words and phrases of the text together.

II. Word Study

1. capacitance [k?'p?sit?ns] n. 电容；电流容量；机械容量

1) related phrases：input capacitance输入电容equivalent capacitance等效

电容capacitance coupling电容耦合capacitance relay 电容式继电器shunt capacitance分流电容；并联电容anode capacitance阳极电容how they are applied in electronic industry.

2）Features: High voltage, small collector output capacitance.

特点:耐压高,集电极输出电容小。

3）Are there any precautions when adjusting the capacitance value?

调整电容值时有哪些注意事项?

4）The formula of capacitance and voltage dependence of power has been educed. 推导出了功率随电容和电压变化的计算公式。

2. Dimension [d?' men?(?) n; da?-] n. 维；尺寸；容积vt. 标出尺寸adj. 规格的

1) related phrases：angular dimension 角度标注；角度大小linear dimension线性尺寸vertical dimension垂直尺度fit dimension配合尺寸under dimension 尺寸过小dimension scale 标注比例

2）Length is one dimension, and width is another.

长是一种度量，宽又是一种度量。

3) The problem of the vehicle velocity detection is resolved by one dimension video tracing.

通过一维视频跟踪的方式，解决了车辆速度检测的难题。

4) The financial dimension to market high-quality products, quality service to win customers.

维融以优质的产品占领市场，以优质的服务赢得了客户。

3. volume [?v?lju: m ]n. 体积；卷；音量；大量；adj. 大量的vt. 把…收集成卷

1) related phrases：volume label 卷标号bound volume合订本volume control播放控制台volume fraction 体积分率；容积比

critical volume 临界容积stroke volume 冲程容积；心搏量

2）The progress schedule compiled on the basis of volume production.

根据批量产品生产预定时间表编制的进度计划；

3）Large volume of data were gathered.

人们收集了大量的资料。

4）We buy in volume and contract early to get the best prices.

大宗采购和尽早签订合同以获得最低货源价格。

4. accumulate[??kju:mjuleit] vi. 累积；积聚vt. 积攒

1) related phrases：accumulate experience 获取经验accumulate points 积

分accumulate pick 多重选择accumulate funds 积累资金accumulate dose 总剂量，累计剂量

2) When we accumulate more and more such differences between Chinese and English consciously, we will think in English when we speak English. 当我们有意识地积累了越来越多的类似的英汉差异之时，我们就开始用英语思维来表达事物了。

3）Overall, therefore, the country did not accumulate substantial foreign currency reserves. 因此，总体来看，中国没有积累很大的外汇储备。

4）Accumulate and summarize all kinds of index completed. Do the basic and preparation job of financial budget.

积累总结各项指标完成情况的资料，做好财务预算的基础准备工作。

5. intensity [in'tens?ti] n. 强烈；强度；亮度；紧张；集中程度

1) related phrases：field intensity磁场强度earthquake intensity地震强度radiant intensity发光度, 辐射率, 辐射强度loading intensity荷载强度intensity of market position市场地位的集中程度

2) Compact, high magnetic induction intensity and long coil service life.

结构紧凑，磁感应强度高，线圈使用寿命长。

3) This reduces the labor intensity, reduce pollution, conserve water resources. 这就降低了劳动强度、减少污染、节约水资源。

4) Compact, high magnetic induction intensity and long coil service life.

结构紧凑，磁感应强度高，线圈使用寿命长。

6. induced [in'dju:st] adj. 感应的；v. 引诱；说服（induce的过去分词）

1) related phrases：induced circuit感应电路；induced current感生/应电流；induced radiation 感应(生)放射性；induced failure诱发故障；induced operation 诱导运算

2）Nausea and dizziness induced by motion, as in travel by aircraft, car, or

ship. 晕船（车）：由运动引起的恶心和眩晕，如乘飞机、小汽车或轮船3）The road traffic accidents induced by fatigue driving will lead to severe personal casualty and property loss.

疲劳驾驶引发的道路交通事故导致了严重的人身伤亡和财产损失。

III. Language points

1. This current is dependent on the voltage of the battery, on the dimensions of the sample，and on the conductivity of the material itself.

译文：流过材料的电流取决于电池的电压、材料的截面积和材料自身的电阻率。

说明：句中be dependent (on)：“由……决定，取决于”，又如：

1) Seating load and tightness is dependent on back pressure.

阀座密封负载和紧密性与反压力相关。

2) Tourism is a resource and the environment is heavily dependent on the

industry. 旅游业是一个对资源和环境严重依赖的行业。

3) May you find enough inner strength to determine your own worth by yourself, and not be dependent on another's judgments of your accomplishments.

愿你能充分发掘自身潜能，以决定你的价值所在，不要让别人的评判埋没了你的成绩。

2. be defined as：“被定义为”，后接宾语，或“that”引导的宾语从句。如：

1）One ohm is defined as that amount of resistance that will limit the current in a conductor is one ampere when the voltage applied to the conductor is one volt.

译文：l欧姆的定义为：当加到导体上的电压为l伏特时，将导体中的电流限制在1安培所需要的电阻值。

说明：句中第一个that作定语，第二个that引导定语从句，该从句本身包含了一个when引导的时时间状语从句。

2）A molecule may be defined as the smallest particle of matter that can exist without changing its nature.

分子可以被定义为物质在不改变其性质的情况下而能存在的物质的最小粒子。

3) Motion may be defined as a continuous change of a body in position with respect to some other body or bodies at rest.

运动可定义为一个物体相对于另一个或几个静止物体在位置上的连续变化。

3. Capacitors consist of two metal plates that are separated by all insulating material.

译文：电容器是由被绝缘材料分开的两个金属板组成。

说明：句中that引导定语从句，修饰two metal plates，consist of表示

“由……组成”，又如：

1）Audit risks consist of intrinsic risk, control risk and examination risk.

审计风险由固有风险、控制风险和检查风险构成。

2）Modern wind farms consist of turbines that generate electricity.

现代风力农场由发电的涡轮机组成。

4. If the battery is disconnected，the capacitor retains the charge

and the voltage associated with it.

译文：如果断开电池，电容器将保持电荷以及与电荷相关的电压。

说明：句中retain表示“保持；雇；记住”的意思。又如：

1）Help your skin retain moisture.

帮助皮肤保持水分。

2）Retain your original receipt as proof of purchase.

请保留您的原始发票作为购买证明。

3）Money has two functions, one is to retain the value of wealth, the other is an exchange value of the wealth.

金钱有两个职能，一个是保留财富价值，一个是交换财富价值。

5. The capacitance is directly proportional to the dielectric constant of the material and to the area of the plates and inversely to the distance of the plates.

译文：电容器的电容量与介质的介电常数及平板的面积成正比,与平板间的距离成反比。

说明：a）be directly proportional to：“与……成正比”；b）be inversely proportional to：“与……成反比” 又如：

1) The resistance of a thin film/coating is directly proportional to the resistivity, and inversely proportional to the thickness.

薄膜镀膜的电阻与该镀镆的电阻系数成正比,与厚度成反比.

2) The magnitude of the force is found to be inversely proportional to the distance between the conductors.

人们发现力的大小与施力者之间的距离成反比。

6. When a current passes through the coil，a magnetic field is set up around it that tends to oppose rapid changes in current intensity．

译文：当电流通过线圈时，在线圈周围将产生磁场，它将对抗电流的快速变化。

说明：句中that引导定语从旬，修饰a magnetic field，it指代the coil。oppose vt.. vi. 表示“反对；对抗，抗争”，又如：

1）Small banks and some state officials strongly oppose the plan.

小银行以及某些州的官员强烈反对该方案。

2）We oppose all forms of hegemonism and power politics.

反对各种形式的霸权主义和强权政治。

7. Also if a coil is placed on an iron core its inductance will be greater than it was without the magnetic core.

译文：而且，如果线圈中放一个铁芯，它的电感将比没有铁芯的线圈的电感大。

说明：句中than引导一个比较状语从句。inductance [?n'd?kt (?)ns]n. “感应系数；自感应；电感”，又如：

1）DC voltage is determined by AC voltage, inductance on the AC side, and load. 直流侧直流电压是由交流电压、电感及负载决定的；

2）The effects of inductance and capacitance make it necessary to carefully design all AC transmission systems.

电感和电容的影响，使人们必须精心地设计所有的交流输电系统。

8. A coil has an inductance of one henry if an induced emf of one volt is induced in the coil when the current through it changes at the rate of one ampere per second.

译文：当流过线圈的电流以每秒1安培的速度变化时，如果线圈中感应出1伏特感应电动势，那么，线圈的电感就是1亨利。

说明：at the rate of “以……的速度/速率/比率/变化率/频率”又如：

1）Income from property transactions shall be filed and taxed at the rate of 35%.

财产交易所得按35%扣缴率申报纳税。

2）Profits from occasional trade shall be filed and taxed at the rate of 30%.

一时贸易的盈余按30%扣缴率申报纳税。

8．iron core：铁芯magnetic core：磁芯

core [k?:] n. 果心,核心,要点vt. 挖去(水果的)果心

1) related phrases：cable core电缆芯线；电缆心core diameter芯样直径；根径core pin 心型梢；中心销core competence/competence核心能力；关键才能

2）The earth have a core and a mantle around it.

地球的中心是地核，地核的周围是地幔。

3）Team spirit is the core of enterprise culture.

团队精神，是企业文化的核心。

4）The monopoly pricing power is the core meaning.

垄断最核心的意义就是定价权。

5）At the core of competitiveness, like how to attract new competitiveness. 在核心竞争力不足的时候，就想怎么吸引新的竞争力。

IV. Translating Skills

And 引导的句型的译法

And作连词，用来连接词、短语和句子，其基本意义相当于汉语的“和”、“与”、“并且”。但在实际翻译的过程中，特别是在连接两个句子时，它的译法很多，表达的意义可能相差甚远。如果不考虑and 前后成分之间的逻辑关系，只用几种基本译法生硬套用，难免造成理解上的失误，甚至把整个句子意思搞错。

l. And表示原因，例如：

Laser is widely used for developing many new kinds of weapons, and it penetrates almost everything.

激光广泛用于制造各种新式武器，因为为它的穿透力很强。

2. And表示因果，譬如：

1）But since a digital signal is made up of a string of simple pulses, noise stands out and easily removed. 但由于数字信号由一组简单脉冲组成，杂音明显，容易发现，因而容易排除。

2）In l945 a new type of aeroplane engine was invented, it was much lighter and powerful than earlier engines, and enabled war planes to fly faster and higher than ever.

1945年发明了一种新型的飞机发动机。它比早期发动机要轻的多，功率也要大得多，因此采用这种发动机的军用飞机比以往任何时候都飞得更快、更高。

3. And表示目的，例如：

It was later shown that the results of this work were by no means the ultimate，and further work has been put in hand and to provide closer control and more consistent operation in this area.

后来发现，这项研究工作的结果绝非已作定论，而进一步的研究工作已开始，以便在这方面提供较严密的控制和较稳定的操作。

4. And表示承接，譬如：

In many ways, computer is more superior than human brain, and human can rule it.

在许多方面计算机超过人脑，而人却可以控制它。

5. And表示对照，例如：

例: Motion is absolute, and stagnation is relative.

运动是绝对的，而静止是相对的。

6. And表示递进，譬如：

例: The electronic brain calculates a thousand times quicker, and more accurately than is possible for the human being.

电脑的运算速度比人所能达到的要快1000倍，甚至更加准确。

7. And表示转折，例如：

例: There will always be some things that are wrong, and that is nothing to

be afraid of.

错误的东西在所难免，但并不可怕。

8. And表示条件，譬如：

Even if a programmer had endless patience, knowledge and foresight, storing every relevant detail in a computer, the machine’s information would be useless, and the programmer knew little how to instruct it in what human beings refer to as commonsense reasoning.

即使一个编程员很有耐心、知识和远见，把每一个有关细节都存入计算机，如果他不懂得按人类常识推理去对计算机下达指令，机器里的信息也还是没有用途的。

9. And表示结果，例如：

Operators found that the water level was too low so they turned on two additional main coolant pumps, and too much cold water flowing into the system caused the steam to condense, further destabilizing the reactor.

操作人员发现冷却水的水位过低，就启动了另外两台主冷却泵，结果过量的冷却水进入系统使蒸气冷凝，反应堆因而更不稳定。

V. Key to Exercises of the text.

Ex. I

1. The resistors are made from carbon mixtures,

metal films, or resistance wire and have two connecting wires attached. The opposition to current is called electrical resistance.

2. Variable resistors, with an adjustable sliding contact arm, are often used to control volume on radios and television sets.

3. The device capable of doing this is called a capacitor or a condenser. Capacitors consist of two metal plates that are separated by all insulating material.

4. When a changer of one volt per second across it causes the current of one ampere to flow, the condenser is said to have the capacitance of one farad.

5. Inductors consist of a conducting wire wound into the form of a coil. A coil has an inductance of one henry if an induced emf of one volt is induced in the coil when the current through it changes at the rate of one ampere par second.

Ex. II.

1.dimensions，conductivity

2. capacitor

3.

resistance 4. capacitance

5. condenser, farad

6. resistors, connecting

Ex. III

1. Variable resistors are often used to control volume on radios and television sets.

2. The ability of a capacitor to store electrical energy

is termed capacitance.

3. Inductors consist of a conducting wire wound into the form of a coil. A coil of many turns will have

more inductance than one of few turns.

4. The capacitance is directly proportional to the dielectric constant of the material and to the area of the plates and inversely to the distance of the plates.

Key to Exercises of the reading

I. 1B 2C 3B 4A 5C 6A

II. 1. mechanical handy multimeters 2. the cathode-ray tube (CRT)

3. LCDs (Liquid Crystal Displays)

4. an electric

signal

5. two sets of deflection plates

6. electronic

principles

VI. 阅读材料参考译文

测试仪器

一旦怀疑某个元件出故障，就得单独做些测试。常用的测试与测量仪器如下：

万用表

万用表有时候被称为伏特-欧姆-毫安表。只具有电压(伏特)和电阻档(欧姆)的万用表也叫伏欧表。万用表主要有两种：机械指针式万用表和数字式万用表。初学者最好使用指针式，因为指针式万用表有助于他们熟悉一些电子原理。

使用万用表时，首先你要将万用表平放在桌子上，检查表针是否指向表盘最左端底部黑色分度的零位。如没指到零位(如有偏离)，可慢慢转动万用表上的螺钉(调整旋钮)直到(指针)归零。然后将测试引线连接起来。将“量程”旋钮调至适当的项目和量程上。将表笔插到正确的插孔内，使表笔夹紧被检测部件的末端，然后再读出表上的读数。

万用表可以用来测量电流、电压、电阻等，也可以检测各种装置的电器故障，比如：检测熔丝，测量墙上插座的电压值，检测房顶上的天线，查明墙上的开关是否有了毛病，并完成许多其他家用电器的检修工作。检测故障时，在被检测设备通电的情况下，可以测量电压，而在测量电阻时却要切断被检测设备的电源。将万用表上读数值与使用手册说明上所标定的额定数值对比一下，你就可以得到故障所在位置的线索。

示波器

示波器是一种显示仪器。你可以用它来研究电信号(例如交流电流和电压)的波形。它也可用来测量电压、电流、功率和频率；实际上，它几乎可以测量涉及到振幅和波形的任何一种量。

示波器的心脏是阴极射线管(CRT)。它由管座、管颈(电子枪在内)、灯泡和面板(显示屏)构成。而电子枪由阴极、控制栅、阳极和两套偏转板构成。阴极受热时发射电子，形成电子束。电子束快速从左至右扫过阴极射线管的荧光屏。然而，近来大多数用于示波器的阴极射线管已经由LCDs(液晶显示器)取代，液晶显示器大大地减轻了仪器的重量、缩小了仪器的体积。

VII 课文翻译

第14单元电阻器、电容器和电感器

1．电阻

假若将电池连接在导电材料上，一定数量的电流将流过该材料，流过材料的电流取决于电池的电压、材料的截面积和材料自身的电阻率。对电流的阻力叫电阻，用字母符号R表示。电阻的单位是欧姆，通常用W表示。l欧姆的定义即：当加到导体上的电压为l伏特时，将导体中的电流限制在1安培所需要的电阻值。较大的电阻值常用千欧（kW）和兆欧（M W）来表示。

电阻器由碳混合物、金属薄膜或电阻丝制成，

它有两个连线接头。常常用带有滑动臂的可变电阻器来控制收音机和电视机的音量。

2．电容器

电能可以储存在电场中，能够储存电能的装置叫电容器。电容器是由被绝缘材料分开的两个金属板组成。如果电池被连接在两个金属板上，电荷将经过很短的流动而汇集在一个电极板上。假若断开电池，电容器将保持电荷以及与电荷相关的电压。

电容器储存电能的能力叫电容。电容器的电容与介质的介电常数及平板的面积成正比，与平板间的距离成反比，其大小用法拉表示。当电容器两端的电压以每秒1伏的速率变化，产生的电流为1安培时，就称电容器的电容为1法拉。在无线电方面的计算中，法拉单位太大，因此常用微法（10-6法拉）和皮法（10-12法拉）。

3．电感

电感是由绕成线圈形状的导线组成。当电流通过线圈时，在线圈周围将产生磁场，它将阻止电流的快速变化。一切线圈，都有电感。

匝数多的线圈比匝数少的线圈电感更大。而且，假若线圈中放一个铁芯。它的电感将比没有铁芯的线圈的电感更大。电感的单位是亨利。当流过线圈的电流以每秒1安培的速度变化时，如果线圈中感应出1伏特感应电动势，那么，线圈的电感就是1亨利。用于无线电设备的电感值的变化范围很大。