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1、<p><p>&lt;p&gt;&amp;lt;p&amp;gt;PART 1电路和电子工程基础 A 电路1 In the case of a resistor, the voltage-current relationship is given by Ohms law, which states that the voltage across the resistor is equal to the current through the resistor multiplied by the
2、 value of the resistance.就电阻来说，电压电流的关系由欧姆定律决定。欧姆定律指出：电阻两端的电压等于电阻上流过的电流乘以电阻值。2It may be that the inductor voltage rather than the current is the variable of interest in the circuit.或许在电路中，人们感兴趣的变量是电感电压而不是电感电流。B 三相电路1 Viewed in this light, it will be found that the analysis of three-phase circuits is
3、little more difficult than that of single-phase circuits. 这样看来，三相电路的分析比单相电路的分析难不了多少。2 At unity power factor，the power in a single-phase circuit is zero twice each cycle在功率因数为1时，单相电路里的功率值每个周波有两次为零。3 It should be noted that if the polarity of point A with respect to N ( ) is assumed for the positive h
4、alf-cycle, then when used in the same phasor diagram should be drawn opposite to, or 180&amp;amp;#176; out of phase with, .应该注意，如果把A点相对于N的极性（ ）定为正半周，那么 在用于同一相量图中时就应该画得同 相反，即相位差为180&amp;amp;#176;。A 运算放大器1 One problem with electronic devices corresponding to the generalized amplifiers
5、is that the gains, AU or AI, depend upon internal properties of the two-port system.对应于像广义放大器这样的电子装置，一个问题就是增益 AU 或者AI ，它们取决于两输入端系统的内部特性。2 This is one of the key features of Op-Amp designthe action of the circuit on signals depends only upon the external elements which can be easily varied by the des
6、igner and which do not depend upon the detailed character of the Op-Amp itself.这是运算放大器设计的重要特征之一在信号作用下，电路的动作仅取决于能够容易被设计者改变的外部元件，而不取决于运算放大器本身的细节特性。B 晶体管1 Put very simply a semiconductor material is one which can be “doped” to produce a predominance of electrons or mobile negative charges (N-type); or
7、“holes” or positive charges (P-type).简单地说，半导体是这样一种物质，它能够通过“掺杂”来产生多余的电子，又称自由电子（N型）；或者产生“空穴”，又称正电子（P型）。2 TO1 is the original transistor shapea cylindrical “can” with the three leads emerging in triangular pattern from the bottom. Looking at the base, the upper lead in the “triangle” is the base, the o
8、ne to the right (marked by a color spot) the collector and the one to the left the emitter.TO1是最早的一种晶体管形状即一个带有三个引脚的圆柱体“外罩”，这三个引脚在底部形成三角状。首先要注意的是，“三角形”上面的引脚是基极，其右面的引脚（由一个彩色点标出）为集电极，其左面的引脚为发射极。 A 逻辑变量与触发器1 We shall now briefly discuss the relevance of such terminology, and in so doing we shall bring o
9、ut the special aptness of the designations “true” and “false” to identify the possible values of a variable. 现在我们将简要地讨论一下这些术语之间的关联，并在此过程中阐明用标示“真”和“假”来识别一个变量的可能值的特殊用途。2 Just as other algebras deal with variables which have a numerical significance, Boolean algebra deals with propositions and is an ef
10、fective tool for analyzing the relationships between propositions which allow only two mutually exclusive alternatives.和其他处理有数字意义的变量的代数一样，布尔代数处理的是命题，而且布尔代数对于分析仅有两个互反变量命题之间的关系是一种有效的工具。3 There is a generally prevailing attitude in digital systems to view logic 0 as a basic, undisturbed, unperturbed, q
11、uiescent state and to view the logic 1 state as the excited, active, effective state, i.e., the state arrived at “after something has happened.”在数字系统中，普遍的观点是把逻辑0看成一个基本的、无干扰的、稳定的、静止的状态，把逻辑1看成一个激励的、活跃的、有效的状态，也就是说，这种状态是发生在“某种操作动作之后”。B 二进制数字系统1 Such devices operate well in a two-state or binary system,
12、using conduction and cutoff as the operating states, and as a result the binary number system is generally employed in internal operations in digital computers.将导通和关断作为工作状态，这样的装置可以在两态即二进制系统中运行，因此数字计算机中的内部操作一般采用二进制系统。2 Given the basic idea of a chain of positive and negative, or positive and zero, or
13、 zero and negative pulses as representing binary 1s and 0s, there are many possible codes in which the pulses might be transmitted.给出一串正脉冲和负脉冲，或正脉冲和零，或者零和负脉冲来表示二进制的1及0时，就会有许多这些脉冲可以传递的码。A 功率半导体器件1 Power diodes provide uncontrolled rectification of power and are used in applications such as electropla
14、ting, anodizing, battery charging, welding, power supplies (DCand AC), and variable-frequency drives.电力二极管提供不可控的整流电源，这些电源有很广的应用，如：电镀、电极氧化、电池充电、焊接、交直流电源和变频驱动。 2 A gate turn-off thyristor (GTO), as the name indicates, is basically a thyristor-type device that can be turned on by a small positive gate
15、current pulse, but in addition，has the capability of being turned off by a negative gate current pulse门极可关断晶闸管，顾名思义，是一种晶闸管类型的器件。同其他晶闸管一样，它可以由一个小的正门极电流脉冲触发，但除此之外，它还能被负门极电流脉冲关断。3 Such a gate current pulse of very short duration and very large di/dt has small energy content and can be supplied by multi
16、ple MOSFETs in parallel with ultra-low leakage inductance in the drive circuit.这样一个持续时间非常短、di/dt非常大、能量又较小的门极电流脉冲可以由多个并联的MOSFET来提供，并且驱动电路中的漏感要特别低。 B 电力电子变换器1 The efficiency of the rectifiers is very high, typically in the vicinity of 98%, because device conduction loss is low and switching loss is practically negligible.由于器件开通时损耗低，且其开关损耗几乎可忽略不计，故该类整流器的效率很高，典型值约为98。2 A variable voltage source can be converted to a variable current source by connection a large inductance in series and co&amp;lt;/p&amp;gt;&lt;/p&gt;</p></p>
