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Lesson1
Knowing the Electronic Components

There are a large number of symbols which represent an equally large range of electronic components. It is important that you can recognize the more common components and understand what they actually do. A number of these components are drawn below, and it is interesting to note that often there is more than one symbol representing the same type of component.

Resistors

Resistors restrict the flow of electric current, for example, a resistor is placed in series with a Light-Emitting Diode (LED) to limit the current passing through the LED. Fig.1-1 shows resistor example and circuit symbol.

Fig.1-1 Resistor Example and Circuit Symbol

Resistors may be connected either way round. They are not damaged by heat when soldering.

Capacitors

Capacitors store electric charge. They are often used in filter circuits because capacitors easily pass AC (changing) signals but they block DC (constant) signals. Fig.1-2 shows capacitor examples and circuit symbol.

Fig.1-2 Capacitor Examples and Circuit Symbol

Inductor

An inductor is a passive electronic component that stores energy in the form of a magnetic field. An inductor is a coil of wire with many windings, often wound around a core made of a magnetic material,like iron. Fig.1-3 shows inductor examples and circuit symbol.

Fig.1-3 Inductor Examples and Circuit Symbol

Diodes

Diodes allow electricity to flow in only one direction. The arrow of the circuit symbol shows the direction in which the current can flow. Diodes are the electrical version of a valve and early diodes were actually called valves. Fig.1-4 shows diode examples and circuit symbol.

Fig.1-4 Diode Examples and Circuit Symbol

Transistors

There are two types of standard transistors, NPN and PNP, with different circuit symbols. The letters refer to the layers of semiconductor material used to make the transistor. Fig.1-5 shows transistor examples and circuit symbols.

Fig.1-5 Transistor Examples and Circuit Symbols

Integrated Circuits (Chips)

Integrated Circuits are usually called ICs or Chips. They are complex circuits which have been etched onto tiny chips of semiconductor (silicon). The chip is packaged in a plastic holder with pins spaced on a 0.1"(2.54 mm) grid which will fit the holes on stripboards and breadboards. Very fine wires inside the package link the chip to the pins. Fig.1-6 shows integrated circuits example.

Fig.1-6 Integrated Circuits Example

Light Emitting Diodes (LEDs)

LEDs emit light when an electric current passes through them.

LEDs must be connected the correct way round, and the diagram may be labelled “ a ” or “+” for anode and “ k ” or “-” for cathode (yes, it really is “k”, not “c”, for cathode!). The cathode is the short lead and there may be a slight flat on the body of round LEDs. Fig.1-7 shows LED example and circuit symbol.

Fig.1-7 LED Example and Circuit Symbol

Other Electronic Components

Fig.1-8 shows other electronic component examples and circuit symbols.

Fig.1-8 Other Electronic Component Examples and Circuit Symbols

New Words

electronic [iˌlek'trɔnik] adj. 电子的,电子仪器的

electronics [iˌlek'trɔniks] n. 电子学,电学,电子工业

component [kəm'pəunənt] n. & adj. 成分,元件;组成的,构成的

symbol ['simbl] n. 符号,标志,象征

resistor [ri'zistə] n. 电阻器

restrict [ri'strikt] vt. 限制,约束,限定

current ['kʌrənt] n. 电流

series ['siəri:z] n. 连续,系列,丛书,级数

capacitor [kə'pæsitə] n. 电容器

charge [tʃɑ:ʤ] n. 电荷

inductor [in'dʌktə] n. 感应器,电感

magnetic [mæɡ'netik] adj. 磁的,有磁性的,有吸引力的

field ['fi:ld] n. 场

diode ['daiəud] n. 二极管

valve [vælv] n. 电子管,真空管

transistor [træn'sistə] n. 晶体管

integrated ['intiɡreitid] adj. 综合的,完整的

circuit ['sə:kit] n. 电路

chip [tʃip] n. 芯片

semiconductor [ˌsemikən'dɔktə] n. 半导体

silicon ['silikən] n. 硅,硅元素

anode ['ænəud] n. 阳极,正极

cathode ['kæθəud] n. 阴极

microphone ['maikrəfəun] n. 扩音器,麦克风

speaker ['spi:kə] n. 扬声器,喇叭

fuse [fju:z] n. 保险丝,熔丝

filament ['filəmənt] n. 细丝,灯丝

motor ['məutə] n. 发动机,电动机

solenoid ['səulənɔid] n. 螺线管

switch [switʃ] n. & vt. 开关;转换

Phrases and Expressions

light-emitting diode 发光二极管

AC (Alternating Current) 交流电

DC (Direct Current) 直流电

Notes

1. There are a large number of symbols which represent an equally large range of electronic components.

译文:这些符号代表了绝大多数的电子元件。

2. It is important that you can recognize the more common components and understand what they actually do.

译文:能够识别更多的普通元件,以及了解它们的实际用途是很重要的。

3. A number of these components are drawn below, and it is interesting to note that often there is more than one symbol representing the same type of component.

译文:下面画出了许多电子元件,有趣的是,一种类型的元件常常可以用多种符号表示。

4. They are complex circuits which have been etched onto tiny chips of semiconductor (silicon). The chip is packaged in a plastic holder with pins spaced on a 0.1"(2.54 mm) grid which will fit the holes on stripboards and breadboards.

译文:它们是固化在微小的半导体(硅)芯片上的复杂电路。该芯片被封装在一个塑料固定物上,引脚间距为0.1英寸(2.54 mm),适合条形板和面包板的孔距。

Exercises

1. Write T (True) or F (False) beside the following statements about the text.

a. One symbol represents a type of component.

b. Resistors are damaged by heat when soldering.

c. Capacitors are not often used in filter circuits.

d. Both capacitor and inductor are passive electronic component.

e. Inductor stores electric charge.

f. Diodes allow electricity to flow either one direction.

g. Diodes are also called valves.

h. The symbol of NPN and PNP transistors is same.

i. ICs are complex circuits which have been etched onto tiny chips of semiconductor.

j. LEDs is one type of diodes.

2. Match the following terms to appropriate definition or expression.

3. Fill in the missing words according to the text.

a. In the common components, _____ may be connected either way round.

b. _____ is a passive electronic component that stores electric charge.

c. Inductors store energy in the form of _____.

d. Diodes allow electricity to flow in _____ direction.

e. The _____ of the LEDs is the short lead and there may be a slight flat on the body of round LEDs.

4. Translate the following sentences into Chinese.

a. Modern advances in the fields of computer, control system, communications have a close relationship with electronics.

b. The field of electronics includes the electron tube, transistor, integrated circuit and so on.

c. Although resistors, capacitors and inductors form important elements in electronic circuit, it is essential to know something about resistance, capacitance and inductance.

d. Electronic technology is developing rapidly in the world. And electronics industry is equipped to make yet another giant step forward. m2jPdYrjDpPFcG31S2NaVuDMTpQgbFX/eas/9nIXG4DnQJrgVSznhN5kYCE/rRi2

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