電子與通信技術專業(yè)英語UnitⅠ-4課件

1、劉 騁 蔡 靜 劉小芹 主編電子與通信技術專業(yè)英語（第5版）高職高專電子信息類“十三五”規(guī)劃教材English on Electronic and Telecommunication Technology01Unit Basic Knowledge of ElectronicsLesson 4 Transistor Voltage Amplifier Unit New Wordsoscilloscope siluskup n. 示波器alternating :lt,neiti a. 交互的amplifier mplifai n. 放大器junction dkn n. 連接, 接合, 交叉點,

2、匯合處resistor rizist n.電阻器quiescentkwaiesnt a. 靜止的New Wordsbiased baist a. 結果偏倚的, 有偏的silicon silikn n. 硅, 硅元素superimpose ,sju:primpuz v. 添加, 雙重Proportionateprup:nit a. & v. 成比例的，成比例equation ikwein n. 方程式, 等式Phrases and Expressionsto convertinto 把轉變成as a result 結果Amplifiers are necessary in many types

3、of electronic equipment such as radios, oscilloscopes and record players. Often it is a small alternating voltage that has to be amplified. A junction transistor in the common-emitter mode can act as a voltage amplifier if a suitable resistor, called the load, is connected in the collector circuit.L

4、esson 4 Transistor Voltage AmplifierChinese Translation of Texts放大器廣泛用于各種電子設備，如收音機、示波器、錄音機等，因為常有小的交流電壓需要放大。一個結型晶體管連成共發(fā)組態(tài)，在其集電極回路中接入合適的電阻，稱為負載，則可構成電壓放大器。第 4 課 晶體管電壓放大器Chinese Translation of TextsThe small alternating voltage, the input ui, is applied to the base-emitter circuit and causes small chang

5、es of base current which produce large changes in the collector current flowing through the load. The load converts these current changes into voltage changes which form the alternating output voltage uo (uo being much greater than ui).Chinese Translation of Texts一個小的交流輸入電壓ui，加在基-射回路中，產生小的基極交變電流進而產生

6、一個大的集電極交變電流流過負載，負載將交變電流轉變成交變電壓即為輸出交流電壓uo(uo比ui大)。Chinese Translation of Texts A transistor voltage amplifier circuit is shown in Fig.4-1. To see just the voltage amplification occurs, consider first the situation when there is no input, i.e. ui= 0, called the quiescent (quiet) state.Chinese Translat

7、ion of Texts 一個簡單的電路如圖4-1所示，表明了電壓放大的過程，首先考慮沒有輸入電流，即ui=0的情形，稱為靜態(tài)。Chinese Translation of Texts For transistor action to take place the base-emitter junction must always be forward biased. A simple way of ensuring this is to connect a resistor RB, called the base-bias resistor. A steady (D.C.) base cur

8、rent IB flows from battery +, through RB into the base and back to battery-, via the emitter. The value of RB can be calculated once the value of IB for the best amplifier performance has been decided.Chinese Translation of TextsChinese Translation of Texts 晶體管工作在放大狀態(tài)時其發(fā)射結必須為正向偏置。為保證發(fā)射結正偏，簡單的方法是接一個電

9、阻RB，稱為基極偏置電阻?；鶚O偏置電流IB從電源正極流出，經RB流入基極；再經發(fā)射極流回電源負極。一旦IB在放大器的最佳狀態(tài)下確定后，可以隨之計算出RB的值。 If VCC is the battery voltage and VBE is the base-emitter junction voltage (always about +0.6V for an n-p-n silicon transistor), then for the base-emitter circuit, since D.C. voltages add up, we can write VCC = IB RB + V

10、BE (1)Chinese Translation of Texts 如果VCC為電源電壓，VBE為發(fā)射結電壓（NPN硅管為0.6V），則對基極回路，若加有交流電壓，有 VCC = IB RB + VBE (1)Chinese Translation of Texts IB causes a much larger collector current IC which produces a voltage drop ICRL across the load RL. If VCE is the collector-emitter voltage, then for the collector-e

11、mitter circuit VCC = ICRL + VCE(2)Chinese Translation of Texts IB產生了一個相當大的集電極電流IC，其在負載RL上產生電壓降IC RL。若VCE為集電結電壓，則對集電極回路，有 VCC = IC RL + VCE (2)Chinese Translation of Texts When ui is applied and goes positive it increases the base-emitter voltage slightly (e.g. from +0.60 V to +0.61 V). When ui swing

12、s negative, the base-emitter voltage decreases slightly (e.g. from +0.60V to +0.59V). As a result a small alternating current is superimposed on the quiescent base current IB which in effect becomes a varying D.C.Chinese Translation of Texts 當交流電壓ui加入且為正時，基極電壓略有增加（如從0.60V到0.61V）；當ui為負時，基極電壓略有下降（如從0.

13、60V到0.59V）。結果是一個小的交流電流疊加在靜態(tài)基極電流IB上并產生一個變化的交流電壓。Chinese Translation of Texts When the base current increases, large proportionate increases occur in the collector current. From equation (2) it follows that there is a corresponding large decrease in the collector-emitter voltage (since Vcc is fixed).

14、A decrease of base current causes a large increase of collector-emitter voltage. In practice positive and negative swings of a few milli-volts in Ui, can result in a fall or rise of several volts in the voltage across RL and so also in the collector-emitter voltage.Chinese Translation of Texts 當基極電流

15、增大，集電極電流大幅增大。由式（2）可知，將相應引起集射間電壓大幅下降（因為VCC一定）。同理，基極電流減小將引起集射間電壓大幅增加。即Ui在正負間有微伏數(shù)量級的擺動，就會導致負載RL上的電壓及集射間電壓有較大的幅值變化。Chinese Translation of Texts The collector-emitter voltage may be regarded as an alternating voltage superimposed on a steady direct voltage, i.e. on the quiescent value of VCE. Only the al

16、ternating part is wanted and capacitor C blocks the direct part but allows the alternating part, i. e. the output uo to pass.Chinese Translation of Texts 集射間電壓可以認為是一個交流電壓疊加在靜態(tài)直流電壓（即靜態(tài)電壓VCE）之上，若只需交流部分，則可利用電容器C的隔直流作用，將直流部分去掉，只允許交流電壓uo通過。Chinese Translation of TextsNotesOften it is a small alternating

17、voltage that has to be amplified. 通常小的交流電壓需要放大。這是一個常見句型，it是形式主語，that has to be amplified引導真正意義上的主語從句。1Noteswhich produce large changes in the collector current flowing through the load. (1) which引出base current；(2) flowing through the load是現(xiàn)在分詞短語，充當后置定語，修飾collector current2NotesThe load converts thes

18、e current changes into voltage changes which form the alternating output voltage uo (uo being much greater than ui). 負載將交變電流轉變成交變電壓即為輸出交流電壓uo(uo比ui大)。 (1) to convert into ：把 變成, 相當于to change into ; (2) which form the alternating output voltage uo是定語從句，修飾voltage changes; (3) alternating是現(xiàn)在分詞短語，修飾outp

19、ut voltage。3NotesA simple way of ensuring this is to connect a resistor RB, called the base-bias resistor, as shown. 簡單的方法是接一個電阻RB，稱為基極偏置電阻。 不定式to connect a resistor RB充當表語，其中called the base-bias resistor是過去分詞短語，充當定語；as shown其義為“如圖所示”。4NotesAs a result a sma1l alternating current is superimposed on

20、the quiescent base current IB which in effect becomes a varying d.c. 結果是一個小的交流電流疊加在靜態(tài)基極電流IB上并產生一個變化的交流電壓。 (1) as a result：“結果”；（2）which in effect becomes a varying d.c.是定語從句，修飾the quiescent base current IB5Notes and so also in the col1ector-emitter voltage. so這里指can also result in a fall or rise of

21、several volts .6NotesThe collector-emitter voltage may be regarded as an alternating voltage superimposed on a steady direct voltage, i.e. on the quiescent value of VCE. 集-射間電壓可以認為是一個交流電壓疊加在靜態(tài)直流電壓（即靜態(tài)電壓VCE）之上。 過去分詞短語superimposed on a steady direct voltage, i.e. on the quiescent value of VCE充當定語，修飾an

22、 alternating voltage7Exercises 1. Write T (True) or F (False) beside the following statements about the text.a. Amplifiers are necessary in many types of electronic equipment such as radios, oscilloscopes and record players. Often it is a large alternating current that has to be amplified.b. A junct

23、ion transistor in the common-emitter mode can act as a resistance amplifier.c. The small alternating voltage is applied to the base-emitter circuit and causes large changes of base current which produce small changes in the collector current flowing through the load.d. The load converts current chan

24、ges into voltage changes, which form the alternating output voltage.Exercises 1. Write T (True) or F (False) beside the following statements about the text.e. For transistor action to take place the base-emitter junction must always be forward straight line.f. When the base current increases, large

25、proportionate increases occur in the collector current.g. A decrease of base current causes a large increase of collector-emitter voltage.h. The collector-emitter voltage may be regarded as an alternating voltage superimposed on a steady direct voltage.Exercises 1. Write T (True) or F (False) beside

26、 the following statements about the text.a. Amplifiers are necessary in many types of electronic equipment such as radios, oscilloscopes and record players. Often it is a large alternating current that has to be amplified.b. A junction transistor in the common-emitter mode can act as a resistance am

27、plifier.c. The small alternating voltage is applied to the base-emitter circuit and causes large changes of base current which produce small changes in the collector current flowing through the load.d. The load converts current changes into voltage changes, which form the alternating output voltage.

28、F FFTExercises 1. Write T (True) or F (False) beside the following statements about the text.e. For transistor action to take place the base-emitter junction must always be forward straight line.f. When the base current increases, large proportionate increases occur in the collector current.g. A dec

29、rease of base current causes a large increase of collector-emitter voltage.h. The collector-emitter voltage may be regarded as an alternating voltage superimposed on a steady direct voltage.FTT（L33）TExercises2. Match the following terms to appropriate definition or expression.a. loadb. VCCc. uBEd. u

30、oe. ui1. a suitable resistor2. the alternating output voltage3. base-emitter junction voltage4. the base-bias resistor5. battery voltagef. RB6. the small alternating voltage, the inputExercises2. Match the following terms to appropriate definition or expression.a. loadb. VCCc. uBEd. uoe. ui1. a suit

31、able resistor2. the alternating output voltage3. base-emitter junction voltage4. the base-bias resistor5. battery voltagef. RB6. the small alternating voltage, the inputExercises3. Fill in the missing words according to the text.a. A junction transistor in the common-emitter mode can act as a if a s

32、uitable resistor called the , is connected in the collector circuit.b. The load converts these changes into changes, which form the alternating output voltage uo.c. A simple way of ensuring this is to connect a resistor RB, called the . A steady (DC) base current IB flows from battery “+”, through R

33、B into the base and back to battery “”, via the .d. The collector-emitter voltage may be regarded as an superimposed on a steady direct voltage, i.e. on the quiescent value of VCE. Only the alternating part is wanted and capacitor C blocks the direct part but allows the , i.e. the output uo to pass.

34、Exercises3. Fill in the missing words according to the text.a. A junction transistor in the common-emitter mode can act as a voltage amplifier if a suitable resistor called the load, is connected in the collector circuit.b. The load converts these current changes into voltage changes, which form the

35、 alternating output voltage uo.c. A simple way of ensuring this is to connect a resistor RB, called the base-bias resistor . A steady (DC) base current IB flows from battery “+”, through RB into the base and back to battery “”, via the emitter.d. The collector-emitter voltage may be regarded as an a

36、lternating voltage superimposed on a steady direct voltage, i.e. on the quiescent value of VCE. Only the alternating part is wanted and capacitor C blocks the direct part but allows the alternating part, i.e. the output uo to pass.Exercises4. Translate the eighth paragraph into Chinese.When the base current increases, large proportionate incr