电气自动化专业英语.pptx

1、,高等职业教育自动化专业,“双证课程”培养方案规划教材,自动化专业英语,English for Automation,Contents,English for Automation,Unit 1,Unit 2,Unit 3,Unit 4,Unit 5,Unit 6,Unit 7,Unit 8,Unit 9,Unit 10,主编黄星王晓平副主编 蒋凌张巍赵九九 主审黄晶,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit

2、 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English

3、 for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Un

4、it 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1Unit 2Unit 3Unit 4Unit 5Unit 6Unit 7,Unit 8Unit 9Unit 10,English for Automation,Unit 1,English for Automation,Reading AThe main components used in electronics are of two general types:passive(e.g.resistors and capacitors)and active(e.

5、g.transistors and integrated circuits).The main difference between active and passive components is that active ones require to be powered in some way to make them work.Passive Components The ResistorA resistor(Figure 1-1)is a piece of material that obeys Ohms Law.The name comes from its main proper

6、ty;it resists the,allowingustocontrol,flowofchargethroughitself,the,hence current.,Resistors can be made of various kinds of material,but whatever the choice it must conduct some electricity otherwise it wouldnt be of any use.,Unit 1,English for Automation,Two wires are connected to opposite ends of

7、 the resistor(Figure 1-2).When we apply a potential difference between the wires we set up a current from one wire to the other,through the resistor.The size of the current is proportional to the difference in voltage between the wires.The resistance(in units of Ohms)is defined as the ratio of the a

8、pplied voltage,V(in Volts),divided by the current,I(in Amps),produced by the applied voltage.The value is usually displayed using standard colour code(Figure 1-3).,Unit 1,English for Automation,The CapacitorIf you look at a catalogue of electronic components youll find an enormous variety of sizes a

9、nd types of capacitor.However,for most purposes we can divide capacitors into two basic types:dielectric and electrolytic.A capacitor acts as a charge store(Figure 1-4).It contains a pair of metal plates separated by a thin sheet of insulating material.The plates are electrically neutral-the number

10、of positive protons in each exactly equals the number of negative electrons.However,if we connect wires to the plates and apply external voltage we can drag electrons off one plate and push them on to the other.,Unit 1,English for Automation,This takes energy,i.e.we have to do work charging the capa

11、citor.The result is a capacitor with one plate positively charged and the other negatively charged.The energy used to move charge is stored by this imbalance.If we connect two plates together with a resistor,the electrons rush back home releasing their energy again.The voltage between the plates of

12、a charged capacitor is proportional to the amount of charge moved.The charge/voltage ratio for any specific capacitor is called the capacitance(Figure 1-5).The DiodeThere are a number of different electronic devices which tend to be called diodes(Figure 1-6).Although theyre made differently they all

13、 have three things in common.,Unit 1,English for Automation,They have two leads like a resistor.The current they pass depends upon the voltage between the leads.They do not obey Ohms law!As an example we will use a typical diode called a pn-junction.This allows us to explain behavior of diodes.Remem

14、ber,however,that there are other sorts of diodes which are built differently but show the same general behavior.We create a pn-junction by joining together two pieces of semiconductor,one doped n-type,the other p-type.This causes adepletion zone to form around the junction(the join)between the two m

15、aterials.This zone controls the behavior of the diode.,Unit 1,English for Automation,NotesWhen we apply a potential difference between the wires we set up a current from one wire to the other,through the resistor.本句是由When we引导的时间状语从句。本句可译为：当在两导线间施加一个电势差 时，就会有电流通过电阻器从一根导线传递到另一根导线。If we connect wires

16、to the plates and apply an external voltage we can drag electrons off one plate and push them on to the other.本句是 由If we引导的条件状语从句，we can drag为主句部分。本句可译 为：如果我们将导线连接到金属板上，并且外加电压，电子就从一块金 属板扯拽到另一块上。There are other sorts of diodes which are built differently but show the same general behavior.本句为简单句。本句可译

17、为：还有很多种不 同结构的二极管，但他们有相同的一般性能。,Unit 1,English for Automation,Exercise,EXERCISE 1,statements,with T(True)or F(False)according,Mark the following to the passage.,Active components are different from passive components in some way to make them work.TThe resistance is often considered as the ratio of the

18、 current,I(in Amps).FIf wires are connected to the plates and an external voltage is applied electrons can be dragged off one plate and they are pushed on to theother.TAlthough diodes are made differently they all have the same in three ways.TSome of diodes are differently and show different behavio

19、r.F,Unit 1,Exercise,EXERCISE 2Translate the following phrases into Chinese or English.,耗尽层,English for Automation,有源元件,欧姆定律 电势差,施加电压绝缘材料 正质子电子器件,active componentsOhms Lawpotential differenceapplied voltageinsulating materialpositive protonselectronic devicedepletion zone,Unit 1,English for Automatio

20、n,Reading B,Active ComponentsJunctionField Effect TransistorsJunction field effect transistors(JFETs)come in two flavors,p-channel and n-channel(Figure 1-7).In each case a bar,or channel,of one type of semiconductor material is located inside a bulk material of the other kind i.e.p inside n,or n ins

21、ide p.A pair of metallic contacts is placed at each end of the channel.When we apply a voltage between these,a current can flow along the channel from one contact to the other.The contact which launches charges along the channel is called the source;the one that eats them at the other end is called

22、the drain.,Unit 1,English for Automation,In an n-channel device,the channel is made of n-type semiconductor,so the charges free to move along the channel are negatively(hence n)charged-they are electrons.In a p-channel device the free charges which move from end-to-end are positively(hence p)charged

23、-they are holes(Figure 1-8).Remember that a hole is the absence of an electron.In each case the source puts fresh charges into the channel while the drain removes them at the other end.,Unit 1,English for Automation,Bipolar TransistorA Bipolar Transistor(Figure 1-9)essentially consists of a pair of

24、PN Junction Diodes that are joined back-to-back.This forms a sort of a sandwich where one kind of semiconductor is placed in-between two others.There are therefore two kinds of bipolar sandwich,the NPN and PNP varieties.The three layers of the sandwich are conventionally called the Collector,Base,an

25、d Emitter.The reasons for these names will become clear later once we see how the transistor works.Some of the basic properties exhibited by a Bipolar Transistor are immediately recognizable as being diode-like.However,when the filling of the sandwich is fairly thin some interesting effects become p

26、ossible that allow us to use the Transistor as an amplifier or a switch.To see how the Bipolar Transistor works we can concentrate on the NPN variety.,Unit 1,English for Automation,Figure 1-10 shows the energy levels in an NPN transistor when we arent externally applying any voltages.We can see that

27、 the arrangement looks like a back-to-back pair of PN Diode junctions with a thin P-type filling between two N-type slices of bread.In each of the N-type layers conduction can take place by the free movement of electrons in the conduction band.In the P-type(filling)layer conduction can take place by

28、 the movement of the free holes in the valence band.However,in the absence of any externally applied electric field,we find that depletion zones form at both PN-Junctions,so no charge wants to move from one layer to another.,Unit 1,English for Automation,Consider happenswhen,nowwhat weapplya,moderat

29、e voltage between the Collector and Base parts of the transistor.The polarity of the applied voltage is chosen to increase the force pulling the N-type electrons and P-type holes apart(Figure 1-11).This widens the depletion zone between the Collector andbase and so no current will flow.In effect we

30、have reverse-biased the Base-Collector diode junction.The precise value of the Base-Collector voltage we choose doesnt really matter to what happens provided we dont make it too big and blow up the transistor!,Exercise,English for Automation,Unit 1,EXERCISE 3,components,according,tothe,Choosethe inf

31、ormation,bestelectronic given.,A.Transistor B.DiodeC.CapacitorD.ResistorE.ConnectorF.LED,C,E,B,F,D,A,Exercise,Unit 1,EXERCISE 4,Abbreviationsare veryusefulin practical and then translatethem into corresponding,work.Readthem Chineseterms.,A.C.A/DAFAFCAGCAM,English for Automation,Alternating Current A

32、nalog/Digital Audio FrequencyAutomatic Frequency Control Automatic Gain Control Amplitude Modulated,交流,数/模转换 音频,自动频率控制 自动增益控制,调幅,Unit 1,English for Automation,Glance at the structureThe following is the Electronic Component Structure.Sample,Unit 1,English for Automation,Explanations of the NPN Trans

33、istor Terms,Unit 1,English for Automation,EXERCISE 5,ComponentStructures.After,to choosethe suitablewordsor,The following reading them,phrases given,istheElectronic you are required below.,Emitter-Base Junction(EBJ)Emitter(E),PNP,p-type Collector-Base Junction(CBJ)p-type Emitter regionCollector(C),n-type Base regionBase(B),Unit 1,1.,5.,9.,Emitter(E),English for Automation,2.p-type Emitter region,3