自动化专业英语部分课文与翻译

An electrical circuit or network is composed of elements such as resistors , inductors ,

and capacitors connected together in some manner .If the network contains no energy

sources , such as

batteries or electrical generators,it is known as a passive the other hand, if

one

or

more

energy

sources

are

present

,

the

resultant

combination

is

an

active

network.

In

studying

the

behavior

of

an

electrical

network,we

are

interested

in

determining the voltages and currents that exist within the circuit. Since a network is

composed of passive circuit elements,we must first define the electrical characteristics

of these elements.

电路或电网络由以某种方式连接的 电阻器、电感器和电容器等元件组成。

如果网络不包含能源，如电池或发电机，那么就被 称作无源网络。换句话说，如

果存在一个或多个能源，那么组合的结果为有源网络。在研 究电网络的特性时，

我们感兴趣的是确定电路中的电压和电流。

因为网络由无源电路元件组成，

所以

必须首先定义这些元件的电 特性

.

In the case of a resistor, the voltage-current relationship is given by Ohm's law, which

ststes that the voltage across the resistor is

equal to

the current

through the resistor

multiplied by the value of the resistance. Mathematically, this is expressed as

u=iR

where u=voltage , V; i=current, A; R=resistance Ω.

就电阻来说，电压

-

电流的关系由欧姆定律给出，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。在数学上表达为

: u=iR

(1-1A- 1)

式

中

u=

电压，伏特；

i =

电流，安培；

R =

电阻，欧姆。

The voltage across a pure inductor is defined by Faraday's law ,which states that the

voltage

across

the

inductor

is

proportional

to

the

rate

of

change

with

time

of

the

current through the inductor. Thus we have u=Ldi/dt

where di/dt=rate of change of

current ,A/s; L=inductance ,H.

法拉第定律指出：

电感两端的电压正比于流过电

感的电流随时间的变化率。

因此可 得到：

U=Ldi/dt

式中

di/dt =

电流变化率，

安

培

/

秒；

L =

感应系数，

享利。

The

voltage

developed

across

a

capacitor

is

proportional

to

the

electric

charge

q

accumulating on the plates of the capacitor. Since the accumulation of charge may be

expressed as the summation, or integral

, of the

charge increments

dq, we have the

equation u=1/c fdq

where the capacitance C is the proportionality constant relating

voltage

and

charge.

By

definition,

current

equals

the

rate

of

change

of

charge

with

time

and

is

expressed

as

i=dq/dt.

Thus

an

increment

of

charge

dq

is

equal

to

the

current multiplied by the corresponding time increment, or dq=i dt.

电容两端建立的电压正比于电容两极板上积累的电荷

q

。因为电荷的积累可表

示为电荷增量

dq

的和或积分，因此得到的等式为

u=

1/c

fdq

，式中电容量

C

是

与电压和电荷相关的比例常数。

电流等于电荷随时间的变化率，

可< /p>

表示为

i = dq/dt

。因此电荷增量

dq

等于电流乘以相应的时间增量，或

dq = i dt

，

那么等式

(1-1A-3)

可写为式中

C =

电容量，法拉。

A common method of analyzing an electrical network is mesh or loop analysis. The

fundamental

law that is

applied in

this method is

Kirchhoff's

first

law, which states

that the algebraic sun of the voltages around a closed loop is 0 ,or , in any closed loop ,

the sum of the voltage rises must equal the sum of the voltage drops. Mesh analysis

consists

of

assuming

that

currents-termed

loop

currents-flow

in

each

loop

of

a

network ,algebraically summing the voltage drops around each loop ,and setting each

sum equal to 0.

分析电网络的一般方法是网孔分析法或回路分析法。

应用于此方法的基本定律是

基尔霍夫第一定律，

基尔霍夫第一定律指出：

一个闭合回路中的电压代数和为

0

，

换 句话说，

任一闭合回路中的电压升等于电压降。

网孔分析指的是 ：

假设有一个

电流

——

即所谓的回路电流

——

流过电路中的每一个回

路，求每一个回路电压

降的代数和，并令其为 零

One

problem

with

electronic

devices

corresponding

to

the

generalized

amplifiers

is

that the gains, Au or Ai, depend upon internal properties of the two-

port system(u,β

，

Ri

,Ro,

etc).

This

makes

design

difficult

since

these

parameters

usually

vary

from

device

,as

well

as

with

temperature.

The

operational

amplifier,

or

Op-Amp,

is

designed

to

minimize

this

dependence

and

to

maximze

the

ease

of

design.

An

Op-Amp is an integrated circuit that has many component parts such as resistors and

transistors

built

into

the

device.

At

this

point

we

will

make

no

attempt

to

describe

these inner workings.

运算放大器像广义放大器这样的电子器件存在的一个问题就是它们 的增益

AU

或

AI

取决于双端口系统

(m

、

b

、

RI

、

Ro,

等

)

的内部特性。器件之间参数的分散性< /p>

和温度漂移给设计工作增加了难度。

设计运算放大器或