Unit2电子技术专业英语.ppt
Electrical Components 电子元件,Requirement:1.Master what is a resistora capacitora inductor 教学要求:掌握什么是电阻、电容、电感 2.Master the knowledge about translation 掌握翻译知识 3.Practise the reading ability 锻炼阅读能力,Key points:1.Technical words and phrases 教学重点:技术单词和词组 2.The method to translate the text 翻译方法,Part One Resistors 电阻Part Two Capacitors 电容Part Three Inductors 电感,Electrical Components 电子元件,A resistor is an electrical component that resists the flow of electrical current.The amount of current(I)(flowing the circuit)is directly proportional to the voltage across it and inversely proportional to the resistance of the circuit.This is the Ohm law and can be expressed as a formula:.The resistor is generally a linear device and its characteristics form a straight line when plotted on a graph.Resistors are used to limit current flowing to a device,thereby preventing it from burning out,as voltage dividers to reduce voltage for other circuits,as transistor biasing circuits,and to serve as circuit loads.,Part One Resistors 电阻,（原文片段）,第一部分 电阻器电阻器是一种电子元件，它能阻碍电流的流动。在电阻器中流过的电流与加在电阻两端的电压成正比，与电阻的阻值成反比。这就是欧姆定律，可以用公式表示成。电阻器一般是线性元件，它的（伏安）特性曲线形成一条直线。电阻器常用做限流器，限制流过元件的电流以防止元件因流过的电流过大而烧坏。电阻器也可用做分压器，以减少其他电路的电压，如晶体管偏置电路。电阻器还可以用做电路的负载。,Part One Resistors 电阻,Can you“create”your own resistors?Of cause and not difficult.Here is how to do it.Draw a line on a piece of paper with a soft pencil,HB or 2HB will do fine.Make the line thick and about 2 inches(5 cm)long.With your multimeter,measure the ohms value of this line by putting a probe on each side of the line;make sure the probes are touching the carbon from the pencil.The value would probably be around the to depending line.The resistance will drop considerably,if you erase some of it(length-wise obviously!).You can also use carbon with silicon glue and when it dries measure the resistance,etc.,Part One Resistors 电阻,第一部分 电阻器可以自己制作一个电阻（器）吗？当然可以而且不难。这里教你如何做一个电阻（器），用一只软铅笔（HB铅笔或用2HB铅笔更好），在纸上画一条大约2英寸（5cm）长的粗线。用万用表测量这段线的欧姆值，（方法是）把万用表的两个探笔分别与铅笔线的两端相接触，一定要让探笔与线段的碳接触。根据线的（粗细），电阻值大约在-。如果你擦掉一些线，使线明显变短，电阻值就会变小。你也可以用含硅胶的碳来制作电阻器，当硅胶干了以后测量其电阻值。,Part One Resistors 电阻,Part Two Capacitors 电容,A capacitor is an electrical device that can temporarily store electrical energy.Basically,a capacitor consists of two conductors(metal plates)separated by a dielectric insulating material,which increases the ability to store a charge.The dielectric can be paper,plastic film,mica,ceramic,air or a vacuum.The plates can be aluminum discs,aluminum foil or a thin film of metal applied to opposite sides of a solid dielectric.The conductor dielectric-conductor sandwich can be rolled into a cylinder or left flat.,第二部分 电容器电容器是可以暂时存储电能的电子元件。电容器一般由两块导体（金属极板）组成，中间用一层不导电的绝缘材料隔开，这层绝缘材料可以增加电容存储电荷的本领（即增大电容量）。绝缘材料可以是纸、塑料片、云母、陶瓷材料、空气或真空。极板可以是铝薄板、铝箔或一片绝缘板的两面各贴上一层金属薄膜。可以直接把一个这种导体-绝缘体-导体（三明治式）制成平板电容器也可以把它卷起来成为圆柱形电容器。,Part Two Capacitors 电容,Part Three Inductors 电感,An inductor is an electrical device,which can temporarily storeelectromagnetic energy in the field about it as long as current is flowing through it.The inductor is a coil of wire that may have an air core or an iron core to increase its inductance.A powered iron core in the shape of a cylinder may be adjusted in and out of the core.,第三部分 电感器当电流流过电感器时，电感器周围就有电磁场，电感器是以电磁场的形式暂时存储电磁能量的电子元件。电感器是一组线圈，有的电感器时空心的（空气芯），有的线圈中有可增加其电感量的铁芯，（可调电感）有一个强磁的圆柱状铁芯，通过调节铁芯可以增加电感量或减少电感量。,Part Three Inductors 电感,单元补充材料,【Exercises】短语英翻汉、短语汉翻英、句子翻译（答案见附录）,【Reading Material】Nonlinear Resistors 非线性电阻器 2.Transformers 变压器,
