为了测量电阻，我们使用单位“欧姆”。
To measure resistance,we use the unit "ohm".重要的是要应用这些定律。
It is important to apply these laws. 这种装置能用来测量电流电压电阻。
Such a device can be used to measurecurrent,voltage and resistance. 我们想要求这个电流中的电流。
We wish to find the current in the circuit.无线电波的用途之一是发送信息。
One of the uses of radio waves is to transmit intelligence.在这种情况下该物体被说成带电了。
In this case the object is said to be charged.我们感到理解这个概念很困难。
We find it very difficult to understand this concept.工科学生应该知道如何使用计算机。
Engineering studentsshould know how to use acomputer.物体做工的能力被称为能量。
The ability of a body to do workis called energy.重要的是我们要把理论应用于实践。
It is important for us toapply theory to practice.计算在这个电流中流动的电流密度是可能的。
It is possible tocalculate the current flowing inthis circuit.这些是常用的设备。
These arecommonly used devices.电压等取决于电路中的电阻以及所加的电压。
Voltage equalscurrent multiplied byresistance.显然电流与外加电压成正比。
Itis apparent that current isproportional to the appliedvoltage.人们发现的金属都是良导体。
Ithas been found that metals areall good conductors.该机器的效率取决于它能运转多快。
The efficiency of themachine depends on how fastit can run.你知道电位差是什么吗？Doyou know what the potentialdifference is?正如我们将会看到的那样，速度是一个矢量。
As we shallsee,velocity is a vector.这些仪器正是我们需要的。
There instruments are justwhat we need.导线中的电子绝不能从正流向负。
By no means do electronsin a wire flow from the positiveto the negative.所有物质，不论是水、铁还是空气，都是由原子构成的。
Every substance,be it water,iron or air,consists of atoms.(1) If the signal source were direct connected instead of capacitor coupled, there would be a low resistance path from the base to the negative supply line, and this would affect the circuit bias conditions.如果信号源和电路不是用电容耦合而是直接耦合，从基极到负电源线就会有一个低阻通路，并且这将影响到电路偏置状态(2) A conventional operational amplifier (op-amps) can be simply described as ahigh-gain direct-coupled voltage amplifier that has a single output terminal, and because it has both invertingand non-inverting inputterminals, the device canfunction as an inverting,non-inverting, or differentialamplifiers, filters, oscillators,level switches, comparators,etc. 传统的运算放大器(op-amps)可以被简单的描述为一个高增益使电压放大器,优点有一个输出端,因为它既有反向和用户的输入端子,设备能作为一个反向功能,用户,或差分放大器、滤波器、振荡器、液位开关、比较器等。
(3) The differential amplifierhas a high-impedance(constant-current)“tail” to give ita high input impedance and ahigh degree of common-modesignal rejection. It also has ahigh-impedance collector (ordrain) load, to give it a largeamount of signal-voltage gain(typically about 100 dB). (3)微分放大器有一个高祖抗(恒流)“尾巴”给它一个高输入阻抗及高度的共模信号的排斥反应。
它也有一个高祖抗收集器(或排放)负荷,给它一个大量的signal-voltage增益(通常大约100分贝)。
(4) In that circuit, a fixedreference voltage is fed to thenon-inverting terminal.Because of the very highopen-loop voltage gain of theop-amp, the output is driveninto positive saturation (closeto +V) when the samplevoltage goes slightly above thereference voltage, and driveninto negative saturation (closeto -V) when the sample voltagegoes slightly below the reference voltage. 电路、固定的参考电压反馈到用户的终端。
因为非常高电压增益的放大器的开环,输出驱动转化为积极的饱和度(接近+ V)当样品是略高于电压参考电压,并被推入负面饱和度(接近-V)电压略低于样品去参考电压。
(1) For example, to represent the 10 numerals (0, 1, 2, …, 9) and the 26 letters of the English alphabet would require 36 different combinations of 1’s and 0’s. Since 25<36<26, then a minimum of 6 bits per bite are required in order to accommodate all the alphanumeric characters. (2) Furthermore, ripple or voltage spikes may exist in the power supply or ground leads, and other sources of unwantedsignals, called noise, may bepresent in the circuit.(3) For these reasons thedigital levels are not specifiedprecisely, but as indicated bythe shaded region in Figure 3.6,each state is defined by avoltage range about adesignated level, such as 41 Vand 0.20.2 V.(4) At 1 signifies the existenceof a positive pulse in a dynamicpositive-logic system; anegative pulse denotes a 1 in adynamic negative-logic systema 0 at a particular input (oroutput) at a given instant oftime designates that no pulseis present at that particularmoment.1)例如,代表10数字(0、1、2、9、…)和26个字母需要36不同的组合,“1”和“0”。
自从25 < 36 < 26,那么至少6位要求每一口为了适应所有的字母数字字符。
(2)此外,波纹或电压尖峰可能存在的电源或地面商机,其它来源的无用的信号,称为噪音,可能出现在这条赛道。
(3)对这些原因是没有指定的数字水准仪清楚,但所示的阴影区域图3.6中,每个国家都被定义为一个关于一个指定层次电压范围,如41伏特和0.20.2 V。
(4)在1表示存在一种积极的脉冲在动态positive-logic系统、负脉冲代表一个1日在系统动态negative-logic 0在某一特定的输入(或产量)在一个特定的瞬间表示无脉搏是目前在那个时刻。
(1) It is assumed that thereader has a generalknowledge of circuit theory. (2)Which of these methods is determine Reqdepends upon which is the easiest in any given situation.(3) It is an experimental fact that an electric field is established in a conducting rod when there is a temperature difference between its ends. (4) That this condition is sufficient is obvious.(5) It can be shown that any rational function of sin xand cos xcan be integrated.(6) A major advantage of this device is that it operates continuously.(7) In this chapter we shall determine which load receives the maximum power for a given practical voltage source.1)它是假定读者的普遍知识的电路理论。