电子课件-《电工英语(第三版)》-A01-3750-电工英语电子课件unit4

1、ELECTRICAL ENGLISH英语电工Unit 1 Job and WorkplaceUnit 2 Electrical Tools and MaterialsUnit 3 House WiringUnit 4 Measuring InstrumentsContents Unit 5 Motors and TransformersLesson10 Instrument ClassificationLesson 11 Using the MultimeterLesson 12 Using the OscilloscopeUnit 4 Measuring InstrumentsLesson1

2、0 Instrument ClassificationGoal Identify basic types and functions of basic measuring instrumentLook and Study DialogueReadingFurther StudyWords and PhrasesLook and Study Dialogue Reading Further Study104Words and PhrasesA. Look up the words and phrases below in a dictionary. Fill in the blanks with

3、 both Chinese and English answers according to the pictures.contactor; electrical resistance; inductor; magnetic field; alternating current; dial1._2._3._contactor接触器electrical resistance电阻inductor电感Look and Study Dialogue Reading Further Study104Words and PhrasesA. Look up the words and phrases bel

4、ow in a dictionary. Fill in the blanks with both Chinese and English answers according to the pictures.contactor; electrical resistance; inductor; magnetic field; alternating current; dial4._5._6._dial刻度盘magnetic field磁场alternating current交流电Look and Study Dialogue Reading Further Study4Words and Ph

5、rasesB. Look up the measuring instrument names below in a dictionary. Fill in the blanks with both Chinese and English answers according to the pictures.ohmmeterammetervoltmeterwattmeter1._ 2._ 3._ 4._10ammeter安培表voltmeter伏特表wattmeter功率表ohmmeter欧姆表Look and Study Dialogue Reading Further Study74Words

6、 and PhrasesJohn参加电机维修的实习，正尝试确定新安装的接触器不能正常工作的故障原因，并向Peter（B）求助。A: Peter, give me a hand.B: Whats the trouble with you？John.A: I wanted to make sure the new contactors werent going to overload the 24 volt transformer, so I started checking resistance of the coils with my ohmmeter. By my reading of Oh

7、ms law, I got the relationship between electromotive force and resistance. But actual current measured is like wrong value? So what am I doing wrong?10Look and Study Dialogue Reading Further Study74Words and PhrasesJohn参加电机维修的实习，正尝试确定新安装的接触器不能正常工作的故障原因，并向Peter（B）求助。B: John, What a silly mistake you

8、made! Ohms Law in its basic form only applies to purely resistive circuits. The coil in the contactor is not a resistive circuit. It is an inductive circuit. Inductors have an additional resistance due to the flux of the magnetic field when alternating current is applied to the coil.A: I got it.10Lo

9、ok and Study Dialogue Reading Further Study74Words and PhrasesA. Choose the best answer1. What was the trouble with John? _A. The new contactors cant work. B. He doesnt know how to use ohmmeter.C. The ohmmeter cant work. D. The coils of contactors cant work.2. Ohms Law in its basic form only applies

10、 to circuits.A. purely inductive; B. purely resistive; C. any; D. Low voltage3. Inductors have when alternating current is applied to the coil.A. no resistance; B. an additional resistance; C. no magnetic field; D. no electromotive force10ABBLook and Study Dialogue Reading Further Study74Words and P

11、hrasesB. Reorder the letters with your partner.LettersWordsw l aoi c lic magnetance resistship relation10relationshiplawcoilmagneticresistanceLook and Study Dialogue Reading Further Study74Words and Phrases测量仪器的分类The three basic quantities in the electrical measurement are current, voltage and power

12、. The necessary requirements for any measuring instruments are: a) With the introduction of the instrument in the circuit, the circuit conditions should not be altered. Thus the quantity to be measured should not get affected due to the instrument used.b) The power consumed by the instruments for th

13、eir operation should be as small as possible.10Look and Study Dialogue Reading Further Study74Words and Phrases测量仪器的分类The instrument which measures the current flowing in the circuit is called ammeter while the instrument which measures the voltage across any two points of a circuit is called voltme

14、ter. The instruments which are used to measure the power are called power meters or watt-meters.Electrical measuring instruments are mainly classified as: 10Look and Study Dialogue Reading Further Study74Words and Phrases测量仪器的分类a) Indicating Instruments: These instruments make use of a dial and poin

15、ter for showing or indicating magnitude of unknown quantity. b) Recording Instruments: These instruments give a continuous record of the given electrical quantity which is being measured over a specific period.c) Integrating instruments: These instruments measure the total quantity of electricity de

16、livered over period of time.10Look and Study Dialogue Reading Further Study74Words and PhrasesA. List the basic types of electrical measuring quantity and instrument.10quantityinstrumentpowercurrentvoltageintegrating instrumentsindicating instrumentsrecording instrumentsLook and Study Dialogue Readi

17、ng Further Study74Words and PhrasesB. Read the passage again and answer the questions.101. The instrument which measures the voltage across any two points of a circuit is called .2. The instruments which are used to measure the power are called .3. The instrument which measures the current flowing i

18、n the circuit is called .voltmeterwatt-metersammeterLook and Study Dialogue Reading Further Study74Words and PhrasesC. Learn the important grammar and phrase in the text.1. While引导由含有转折关系的两个分句构成的并列句，表示对比。The instrument which measures the current flowing in the circuit is called ammeter while the ins

19、trument which measures the voltage across any two points of a circuit is called voltmeter. 测量电路电流的仪器称为安培表，而测量电路中任意两点之间电压的仪器称为伏特表。练习：他出去散步了，而我却待在家里。英文： 2. which引导限定性定语从句These instruments give a continuous record of the given electrical quantity which is being measured over a specific period. 这些仪器记录电气

20、参数在被测量的某一特定期间内的连续值。练习：这是准备搬进城的一家人.提示：move to英文：10He went out for a walk, while I stayed at home.This is the family which is planning to move to the city.Look and Study Dialogue Reading Further Study74Words and PhrasesOhms Law and Watts Law.Ohms law determines the relationship between Voltage (V), Cu

21、rrent (I), and resistance (R). The simple formula（公式）can be used to determine one unknown（未知）variable（变量）if the other two variables are known. Related to this is Watts Law（瓦特定律）which includes calculations（计算）for power.10Look and Study Dialogue Reading Further Study74Words and PhrasesOhms Law and Wat

22、ts Law.Power is a measure of the overall（全部的）amount of work being done in a system in relation to （有关）time (energy used per second每秒). In an electrical system power can be calculated by using the formula P = V I. From this you can see how the voltage and current in a system relate to the overall amo

23、unt of power used. The unit of a Watt (W) is equivalent to（等于）joules per second（焦耳每秒）, therefore one Watt is equal to（等于）one joule per second.10Look and Study Dialogue Reading Further Study74Words and Phrases10contactor kntkt n.接触器overload ,uvlud vt. 超载resistance rizistns n.电阻coil kil n. 线圈ohmmeter

24、um,mi:t n. 电 欧姆表ohm um n. 欧姆law l: n. 法律；规律relationship rileinip n. 关系electromotive i,lektrumutiv adj.电动势的force f:s n. 力，力量actual ktul adj. 真实的，实际的measure me vt. 测量value vlju: n. 值purely pjuli adv. 纯粹地，仅仅resistive rizistiv adj. 电阻式的inductive indktiv adj.感应的inductor indkt n. 电感due dju: adj.由于，因为flux

25、flks n 通量magnetic mnetik adj.有磁性的alternating :lt,neiti adj. 交替的，交互的quantity kwntti n. 量measurement memnt n. 测量power pau n. 功率introduction ,intrdkn n. 引进；介绍condition kndin n. 条件；情况alter :lt vt. 改变thus s conj. 因此affect fekt vt. 影响consume knsju:m vt. 消耗ammeter mit n. 电流表voltmeter vult,mi:t n. 电压表watt-m

26、eter wt,mi:t n. 功率表classify klsifai vt. 分类dial dail n.刻度盘pointer pint n. 指针magnitude mnitju:d n.量级unknown nnun adj. 未知的integrate intireit vt.使成整体，求的积分Look and Study Dialogue Reading Further Study74Words and Phrases10Ohms law欧姆定律electromotive force电动势due to由于magnetic field磁场alternating current交流电Less

27、on 11 Using the MultimeterGoal Learn useful expressions for using multimeterLook and Study DialogueReadingFurther StudyWords and PhrasesLook and Study Dialogue Reading Further Study114Words and PhrasesA. Look up the words and phrases below in a dictionary. Fill in the blanks with both Chinese and En

28、glish answers according to the pictures.test lead; AC compressor；capacitor; resistor; DC; diode1._2._3._capacitor电容器AC compressor交流压缩机resistor电阻器Look and Study Dialogue Reading Further Study114Words and PhrasesA. Look up the words and phrases below in a dictionary. Fill in the blanks with both Chine

29、se and English answers according to the pictures.test lead; AC compressor；capacitor; resistor; DC; diode4._5._6._4 diode二极管; 5. DC直流电; 6. test lead测试引线diode二极管DC直流电test lead测试引线Look and Study Dialogue Reading Further Study4Words and PhrasesB. Look up multimeter names below in a dictionary. Fill in t

30、he blanks with both Chinese and English answers according to the pictures.analog multimeterdigital multimeter111._ 2._digital multimeter数字万用表analog multimeter模拟万用表Look and Study Dialogue Reading Further Study74Words and PhrasesJane（B）给他的朋友Peter（A）打电话，谈起她刚刚完成的空调修理工作。A: Hello, Peters speaking.B: Peter

31、，Im Jane.A: Hi, Jane! Whats new?B: I have just finished my first air-conditioner repairing task. A: Really? Whats it like?B: An air-conditioner of our customer was not working. I checked the capacitor of compressor motor with a multimeter and founded it need replacement.11Look and Study Dialogue Rea

32、ding Further Study74Words and PhrasesJane（B）给他的朋友Peter（A）打电话，谈起她刚刚完成的空调修理工作。A: How do you know that?B: A typical capacitor failure will cause a motor not to have the extra kick to get to start up. I discharged the capacitor first and tested it with a multimeter. The result showed the capacitor didnt

33、 hold a charge.A: Well done, Jane.11Look and Study Dialogue Reading Further Study74Words and PhrasesA. Listen to the dialogue and circle Yes or No.1. Peter has just finished air-conditioner repairing work. Yes No2. John checked the capacitor of compressor motor with an ohmmeter. Yes No3. The capacit

34、or is failure because it didnt hold a charge. Yes No10NoNoYesLook and Study Dialogue Reading Further Study74Words and PhrasesB. Reorder the letters with your partner.11LettersWordsk k c iure failcal typidis chargement replacereplacementkickfailuretypicaldischargeLook and Study Dialogue Reading Furth

35、er Study74Words and Phrases万用表的使用A multimeter is one of the most useful diagnostic tools around. Its useful in testing power supplies, but it also can be used to test fuses, resistors, and batteries. Multimeters are designed to perform many different types of electrical tests, includinga)DC voltageb

36、)AC voltagec)Resistance (Ohms)d)Diodese)Amperage11Look and Study Dialogue Reading Further Study74Words and Phrases万用表的使用All multimeters are equipped with red and black test leads. When used for voltage tests, the red is attached to the power source to be measured, and the black is attached to ground

37、. Multimeters use two different readout styles: digital and analog. Digital multimeters are usually auto ranging, which means they automatically adjust to the correct range for the test selected and the voltage present. Analog multimeters must be set manually to the correct range and can be damaged

38、more easily by overvoltage.Multimeters are designed to perform tests in two ways: in series and in parallel. Most tests are performed in parallel mode, in which the multimeter is not part of the circuit but runs parallel to it.11Look and Study Dialogue Reading Further Study74Words and PhrasesA. List

39、 Basic types of electrical tests with multimeter.11_AmperageDC voltageAC voltageResistance (Ohms)DiodesLook and Study Dialogue Reading Further Study74Words and PhrasesB. Match the English with the Chinese. Draw lines.11Be equipped with central heating执行电气测试batteries in series装有集中供暖resistances in par

40、allel串联电池perform electrical tests并联电阻Look and Study Dialogue Reading Further Study74Words and PhrasesC. Learn the important grammar and phrase in the text.1. adjust to调整到Digital multimeters are usually auto ranging, which means they automatically adjust to the correct range for the test selected and

41、 the voltage present. 数字万用表通常有自动的量程，它们可以根据所选择的测试和当前电压自动调整到正确的量程。练习：所有的数值自动调整到了正确的设置。提示：values, settings英文： 2. which引导非限定定语从句Most tests are performed in parallel mode, in which the multimeter is not part of the circuit but runs parallel to it. 大多数的测试以并联的方式完成。在这种方式下，万用表不属于（工作）电路的一部分，而是与（工作）电路并行运行。练习：上

42、周末我去了教堂，我妹妹在那举行过婚礼。提示：get married英文： 11All the values automatically adjust to the correct settings.Last weekend I went to the church, in which my sister got married.Look and Study Dialogue Reading Further Study74Words and PhrasesDigital Multimeter Operation Manual- Dos and DontsUse the right input j

43、ack（插孔）, function（功能）and range.Do not take measurements that exceed（超过）the protection limit values indicated in the specifications（说明书）.Do not touch(接触)the metal tips（尖端）of the test leads when the meter is connected to the circuit to be measured.Do not take voltage measurement if the value between t

44、he terminals（终端）and earth ground exceeds 1000V.Select the highest range if the value scale（等级）to be measured in the manual range is unknown.11Look and Study Dialogue Reading Further Study74Words and PhrasesDigital Multimeter Operation Manual- Dos and DontsDo not connect the meter to any voltage sour

45、ce while the rotary selector（旋转式选择器）is in the current, resistance, capacitance（电容）, diode, continuity range.Disconnect the test leads from the circuit under test before turning the rotary selector to change functions.Do not measure the resistance, capacitance, diode or continuity of live circuits(通电

46、电路).Do not take capacitance measurements until the capacitor to be measured has been fully discharged.Stop using the meter if any abnormalities（异常情况）or faults are observed（观测）.11Look and Study Dialogue Reading Further Study74Words and Phrases11air-conditioner n. 空调capacitor kpsit n.电容器compressor kmp

47、res n. 压缩机multimeter mltimit n. 万用表replacement ripleismnt n. 更换typical tipikl adj. 典型的failure feilj n.故障extra ekstr adj. 额外的kick kik n.反冲力discharge dist:d vt放电charge t:d n. 电荷diagnostic ,dainstik adj. 诊断的resistor rizist n. 电阻器perform pf:m vt. 执行；完成diode daiud n. 二极管equip ikwip vt. 装备，配备lead li:d n.引

48、线source s:s n. 来源readout ri:daut n. 读出digital diditl adj. 数字的analog nl adj. 模拟的auto :tu adj.自动的range reind vt. (在范围内)变动;n. 范围automatically ,:tmtikli adv. 自动地adjust dst vt. 调整select silekt vt. 挑选present preznt vt. 出现；显示，呈现manually mnjuli adv. 手动地damage dmid vt. 损坏overvoltage ,uvvultid n 过电压series sir

49、i:z, -riz n. 串联parallel prlel n. 平行Look and Study Dialogue Reading Further Study74Words and Phrases11start up发动DC abbr. 直流电（direct current）AC abbr. 交流电（Alternating Current）equip with配备test lead测试引线adjust to调整到in series串联in parallel并联Lesson 12 Using the OscilloscopeGoal Learn useful expressions for u

50、sing oscilloscopeLook and Study DialogueReadingFurther StudyWords and PhrasesLook and Study Dialogue Reading Further Study124Words and PhrasesA. Look up the words and phrases below in a dictionary. Fill in the blanks with both Chinese and English answers according to the pictures.wave; charger; rect

51、ifier; PCB; oscilloscope; signal1._2._3._charger充电器PCB印刷电路板oscilloscope示波器Look and Study Dialogue Reading Further Study124Words and PhrasesA. Look up the words and phrases below in a dictionary. Fill in the blanks with both Chinese and English answers according to the pictures.wave; charger; rectifi

52、er; PCB; oscilloscope; signal4._5._6._4. rectifier整流器; 5. signal信号; 6. wave波rectifier整流器rectifier整流器signal信号wave波Look and Study Dialogue Reading Further Study74Words and PhrasesJane（A）看到Peter（B）正在研究一个充电器的电路图，于是提出了几个问题。A: Peter, here is a battery charger circuit diagram. Whats the component in square

53、 c5? B: Thats a transformer, John.A: Oh, I see. What will you do with the diagram, a PCB?B: No. My boss only wants me to test the battery charger with an oscilloscope.A: Im not quite sure where to test it.B: At points A, B and C. A: Whats the component in square D5?B: Thats a full-wave bridge rectif

54、ier.12Look and Study Dialogue Reading Further Study74Words and PhrasesA. Listen to the dialogue and circle Yes or No.1. Peter wants to make a battery charger. Yes No2. John tests the battery charger with an oscilloscope. Yes No3. Peter and John are studying a wiring diagram. Yes No12NoNoNoLook and S

55、tudy Dialogue Reading Further Study74Words and PhrasesB. Reorder the letters with your partner.12LettersWordsu sq aredge bri oscillo scopesquarebridgeoscilloscopeLook and Study Dialogue Reading Further Study74Words and Phrases使用示波器An oscilloscope is a type of electronic test instrument that allows o

56、bservation of constantly varying signal voltages, usually as a two-dimensional graph of one or more electrical potential differences using the vertical (Y) axis and horizontal (x) axis, plotted as a function of time. Although an oscilloscope displays voltage on its vertical axis, any other quantity

57、that can be converted to a voltage can be displayed as well. In most instances, oscilloscopes show events that repeat with either no change or change slowly.12Look and Study Dialogue Reading Further Study74Words and Phrases使用示波器Oscilloscopes are commonly used to observe the exact wave shape of an el

58、ectrical signal. In addition to the amplitude of the signal, an oscilloscope can show distortion, the time between two events (such as pulse width, period) and relative timing of two related signals.Oscilloscopes are used in the sciences, medicine, engineering, and telecommunications industry. Gener

59、al purpose instruments are used for maintenance of electronic equipment and laboratory work.12Look and Study Dialogue Reading Further Study74Words and PhrasesA. Read the passage again and answer the questions.121. An oscilloscope is a type of that allows observation of constantly varying signal volt

60、ages.2. Oscilloscopes are commonly used to observe of an electrical signal.electronic test instrument the exact wave shapeLook and Study Dialogue Reading Further Study74Words and PhrasesB. Reorder the letters with your partner.12LettersWordse w v ase p ul ri pe odve ob serfunc tiontry indus industry