Translate the following sentences into Chinese。
(2)Although current and voltage are the two basic variables in an electric circuit，they are not sufficient by themselves。For practical purposes，we need to know how much
power an electric device can handle。
虽然电流和电压是电路中的两个基本变量，但是它们本身是不足够的。出于实用的目的，
我们需要知道电气设备可以处理多大的功率。
(3)In any linear circuit containing multiple independent sources，the current or voltage at any point in the network may be calculated as the algebraic sum of the individual contributions of each source acting alone。
任一含有多个独立电源的线性电路，某处电压或电流都是电路中各个独立电源单独作用
时，在该处分别产生的电压或电流的叠加。
(5)Since an 8-bit code can represent 256 segments，its codes for the same analog
value are shown with the maximum analog signal of 1.5V equal to 255 。Notice that
the 8-bit code is two groups of 4-bit codes，which are also expressed in
hexadecimal form。
由于一个8 位的代码可以表示256 个段，以此表示的代码对应的模拟值，最大的模拟信号1.5V
取值为255。另外，8 位代码是两组4 位的代码，可以用十六进制形式表示。
(6)After the digital processing system completes its manipulation of the signal ，the output digital codes are coupled to a digital-to-analog converter that changes the digital codes back to an equivalent analog signal。
数字处理系统完成信号的处理后，输出的数字码被传到一个数字转模拟的转换器，将数
字编码转换为相等的模拟信号。
(4)Often instrumentation is not used by itself，but instead as the sensors of larger
electrical systems。For example，a thermocouple might be used to help ensure a
furnace’s temperature remains constant。For this reason，instrumentation
engineering is often viewed as the counterpart of control engineering。
通常测量仪器不单独使用，而作为大型电气系统的传感器应用。例如，热电偶可用于帮
助确保熔炉的温度保持恒定。出于这个原因，仪器仪表工程通常被视为对应于控制工程的配对。
(5)Signal Processing is a very mathematically oriented and intensive area forming the core of digital signal processing and it is rapidly expanding with new applications in very field of electrical engineering such as communications，control，radar，
TV/Audio/Video engineering，power electronics and bio-medical engineering as
many already existing analog systems are replaced with their digital counterparts。
信号处理是非常数字化的，也是构成数字信号处理核心的重点领域，它正在迅速扩展，
应用在电气工程的各个领域中，如通信、控制、雷达、电视/音频/视频技术、电力电子技术和生物
医学工程，以相应的数字系统取代其中现有的模拟系统。
(1)Although we now know that current in metallic conductors is due to negatively charged electrons，we will follow the universally accepted convention that current
is the net flow of positive charges。
尽管现在我们知道金属导体中的电流是由带负电的电子产生的，我们依然遵循电流是正
电荷的流动这个公认的约定。
(3)On the other hand，delta-connected sources are not common in practice because of the circulating current that will result in the delta-mesh if the three-phase voltage are slightly unbalanced。
另一方面，实际中三角形连接的电源并不常用，因为三相电压稍有不平衡就会在三角形
连接的网孔中产生循环电流。
(5)For example，the stator-pole pair A-A’ is energized when the rotor pole-pair a-a’ approaches it to produce the torque by magnetic pull，but is de-energized when pole alignment occurs。
例如，当转子极对a-a’接近定子极对A-A ’时，定子极对A-A ’被通电，通过磁拉力产生
转矩，当两个极对重合时，定子极对A-A ’断电。
(8)The speed error is corrected at the maximum permissible armature current until the speed error becomes small and the current limiter comes out of saturation。在最大允许电枢电流下纠正速度偏差，知道速度偏差减小且限流装置退出饱和状态。
(1)The primary reason for converting to AC power production and distribution was that transformers could be used to increase AC voltage levels for long-distance distribution of electrical power。
转为交流电来进行生产与传输的主要原因是变压器能升高交流电压，以便于电能的远距离传输。(2)In essence，the industry is moving away from simple automation of repetitive tasks and administrative chores，towards using IT as a comprehensive and integrated competitive strategic tool。
从本质上讲，电力工业正从重复性人物和日常管理事物的简单自动化向将信息技术用作
全面综合的竞争性的战略工具转变。
(4)Three are many other considerations such as circuit loading，impedance matching，and frequency response that must be dealt with in order to obtain the most accurate results possible using test equipment。
为了使所用测试设备能获取最准无二的数据，还要考虑其他因素，如电路负载、阻抗匹
配和频率响应等。
(4)Since the torque equation now involves two opposing factors，it is entirely reasonable to expect that a point is reached beyond which further increases in slip culminate in decreased developed torque。
现在，由于转矩方程式包含两个对应的系数，完全有理由得到这样一点，在该点当转差
率继续增加并超过临界值时，所产生的转矩会减少。
(6)With the advanced instruction sets and expanded variable memory capacities of the newer programmable controllers，it is now possible for the system to act as a data concentrator，collecting data about the machine or process it is controlling。
由于新的可编程序控制器采用高级指令集，扩展了变量存储器的容量，这个系统现在可
以作为数据集中器来收集被控制器或过程的数据。
(3)The most outstanding feature of fuzzy set theory，which made it very attractive for applications，is its ability to model the meaning of natural language expressions。模糊
集理论最突出的特点是它能够模拟自然语言表达的意义，这使得它对实际应用非常
有吸引力。
(4)Since we are interested to control a physical parameter of our interest like temperature，pressure，voltage，frequency，position，velocity，concentration，flow，pressure，we must have suitable transducers to measure the variables and use them as suitable feedback signal for proper control。
由于我们想控制自己感兴趣的物理参数，如温度、压力、电压、频率、位置、速度、浓
度、流量、压力等，我们必须用合适的传感器来测量这些变量并作为适当的控制反馈信号来使用。
(5)The principle of superposition states that the response produced by the simultaneous application of two different forcing functions is the sum of the two individual responses。
叠加原理说明，两个不同的作用函数同时作用于系统时的响应等于两个作用函数单独作
用时的响应之和。
(6)Fuzzification translates the input crisp data into the fuzzy representation incorporating the vagueness and imprecision in a natural language，for further processing in FLC。
模糊化将输入的观测数据转换成模糊表示，其中体现了自然语言中的模糊性和不精确性，以便在
FLC 中进行进一步的处理。
(4)In 1871，Siemens choose platinum as the RTD element in a resistance thermometer and still today it is the most common used metal for RTDs besides the more economical nickel or nickel alloys。
在1871 年，西门子选择铂作为电阻温度计的电阻元件，直到今天，它还是除了更经济
的镍和镍合金以外最常见的RTD 的金属。
(5)The resistance of the wire at various temperatures is known and therefore predictable。This predictable change in resistance is used to measure temperature。
在各种温度下的电线的电阻是已知的，因此可被预测出。这种可预测的电阻变化被用来
测量温度。
(6)RTDs are relatively immune to electrical noise and therefore especially suited around motors，generators and other high voltage equipment ( like induction heating)。
RTD 对电噪声不是很敏感，因此特别适合用于电动机、发电机和其他高压设备（如感
应加热器）Ⅲ。Translate the following sentences into English 。
(2)有源元件能产生能量，而无源元件不能。
An active element is capable of generating energy while a passive element is not.
(3)数/模转换之后所需的一个基本功能是滤波。
A basic function required after the digital-to-analog conversion is filtering.
(1)电流源逆变器被用于从直流电流供电产生交流输出电流。
Current source inverters are used to produce an AC output from a DC current supply. (2)直流到交流的转换器从一个直流源产生交流输出波形。
DC to AC converters produce an AC output waveform from a DC source
(3)电压型逆变器在单相和三相的应用中实际使用。
Voltage source inverters have practical uses in both single-phase and three-phase applications.
(5)在设计控制系统时，控制工程师通常使用负反馈。
Control engineers often utilize feedback when designing control systems.
(1)波动与振动系统有关。
Waves are related to oscillating systems.
(5)然而，随着频率的增加，电机的气隙磁通下降，导致产生的转矩降低。
However，as the frequency is increased，the machine air gap flux falls causing low developed torque capability.
(1)设备替代老设备将会使产量大大增加。
The substitution of new equipment to the old result in increase in production.
(2)如何运行一个电力系统使之以最小的成本输电给所有负荷，这是一个重要的问题。
It is an important problem how to operate a power system to supply all the (complex) loads at minimum cost.
(2)抽水机抽水的原理能够用来说明心脏怎样使血液周身循环。
The way that a pump works is used to illustrate how the heart sends blood around the body.
(4)为长距离输电，在主电站将电压升高到较高的值。
At the central station the voltage is stepped up to a higher value for long-distance transmission.
(5)电路故障可能会对依赖电气设备运行的电厂产生的破坏性影响。
Circuit faults can have a devastating effect on power plants that are relying on the operation electrical equipments.
(6)基于安装类型和负载需要，可以采用高达2300V 的电压。
Depending upon the type of installation and the lode requirements，voltages as high a 2300 volts may be used.
(2)从易于处理的简单近似模型到实际一些的模型的转换存在两方面的问题。
The transition from simple approximate models，which are easy to work with，to more realistic models produces two effects.
(3)为了使系统在所有条件下都稳定，对基本的PID 方程的某些修改是必要的。
To make the system stable under all conditions，certain modifications may be necessary to the basic PID equation.
(4)在时域中研究控制系统本质上涉及对系统的瞬态和稳态响应的评价。
The study of a control system in the time domain essentially involves the evaluation of the transient and the steady-state responses of the system.
(1)理想的传感器具有大且恒定的灵敏度。
An ideal sensor will have a large and constant sensitivity.
(2)精确性是准确性的充分不必要条件。
Precision is a necessary but not sufficient condition for accuracy.
(3)传感器的动态响应被假设为线性。
The dynamic response of the sensor is assumed to be linear.
(4)所有的金属对温度的正变化产生正的电阻变化。
All metals produce a positive change in resistance for a positive change in temperature.
(5)RTD 传感器被用于通过RTD 元件电阻和温度的相关性测量温度。
An RTD sensor is used to measure temperature by correlating the resistance of the RTD element with temperature.
第二章第一篇 To say that we live in an age of electronics is an understatement. From the omnipresent integrated circuit to the equally omnipresent digital computer, we encounter electronic devices and systems on a daily basis. In every aspect of our increasingly technological society— whether it is science, engineering, medicine, music, maintenance, or even espionage—the role of electronics is large, and it is growing. 谈论关于我们生活在一个电子学时代的论调是一种空泛的论调。从无处不在的集成电路到同样无处不在的数字计算机，我们在日常活动中总会遇到电子设备和电子系统。在我们日益发展的科技社会的方方面面——无论是在科学、工程、医药、音乐、维修方面甚至是在谍报方面——电子学的作用是巨大的，而且还将不断增强。 In general, all of the tasks with which we shall be concerned can be classified as "signal-processing“tasks. Let us explore the meaning of this term 一般说来，我们将要涉及到的工作被归结为“信号——处理”工作，让我们来探究这个术语的含义吧。 A signal is any physical variable whose magnitude or variation with time contains information. This information might involve speech and music, as in radio broadcasting, a physical quantity such as the temperature of the air in a room, or numerical data, such as the record of stock market transactions. The physical variables that can carry information in an electrical system are voltage and current. When we speak of "signals", therefore, we refer implicitly to voltages or currents. However, most of the concepts we discuss can be applied directly to systems with different information-carrying variables. Thus, the behavior of a mechanical system (in which force and velocity are the variables) or a hydraulic system (in which pressure and flow rate are the variables) can often be modeled or represented by an equivalent electrical system. An understanding of the behavior of electrical systems, therefore, provides a basis for understanding a much broader range of phenomena. 信号就是其与时间有关的量值或变化包含信息的任何物理变量。这种信息或许像无线电广播的演讲和音乐，或许是像室内温度的物理量，或许像股市交易记录的数字数据。在电气系统中能够载有信息的物理变量是电压和电流。因此当我们谈到“信号”，我们不言而喻指的是电压和电流，然而，我们要讨论的大多数概念是可以被直接应用于载有不同信息的变量的系统，因此，一个机械系统（在这个系统中力和速度是其变量）或者液压系统（在这个系统中压力和流速是其变量）的性能通常可以用一个等效的电气系统来模拟或表示。因此，我们对于电气系统性能的理解为理解更宽领域的现象打下了一个基础。 A signal can carry information in two different forms. In an analog signal the continuous variation of the voltage or current with time carries the information. An example, in Fig.2-l, is the voltage produced by a thermocouple pair when the two junctions are at different temperatures. As the temperature difference between the two junctions varies, the magnitude of the voltage across the thermocouple pair also varies. The voltage thus provides an analog representation of the temperature difference. 一个信号可以以两种形式来承载信息。在一个模拟信号中电压或电流随时间而产生的连续变化载有信息。在图2-1中，当一对热电偶的接头处于不同的温度时由热电偶所产生的电压就是一个例子。当两个接头之间的温度差改变时，一对热电偶两端的电压也将改变。于是电压就提供了温度差的模拟表现形式 The other kind of signal is a digital signal. A digital signal is one that can take on values within two discrete ranges. Such signals are used to represent ON-OFF or YES-NO information. An ordinary household thermostat delivers a digital signal tocontrol the furnace. When the
自动化专业英语常用词汇 acceleration transducer 加速度传感器 accumulated error 累积误差 AC-DC-AC frequency converter交-直-交变频器 AC (alternating current) electric drive 交流电子传动 active attitude stabilization 主动姿态稳定 adjoint operator 伴随算子 admissible error 容许误差 amplifying element 放大环节 analog-digital conversion 模数转换 operational amplifiers运算放大器 aperiodic decomposition 非周期分解 approximate reasoning 近似推理 a priori estimate 先验估计 articulated robot 关节型机器人 asymptotic stability 渐进稳定性 attained pose drift 实际位姿漂移 attitude acquisition 姿态捕获 AOCS (attitude and orbit control system) 姿态轨道控制系统attitude angular velocity 姿态角速度 attitude disturbance 姿态扰动 automatic manual station 自动-手动操作器 automaton 自动机 base coordinate system 基座坐标系 bellows pressure gauge 波纹管压力表 gauge测量仪器
第二部分 控制理论 第1章 1.1控制系统的引入 人类控制自然力量的设计促进人类历史的发展,我们已经广泛的能利用这种量进行在人类本身力量之外的物理进程?在充满活力的20世纪中,控制系统工程的发展已经使得很多梦想成为了现实?控制系统工程队我们取得的成就贡献巨大?回首过去,控制系统工程主要的贡献在机器人,航天驾驶系统包括成功的实现航天器的软着陆,航空飞机自动驾驶与自动控制,船舶与潜水艇控制系统,水翼船?气垫船?高速铁路自动控制系统,现代铁路控制系统? 以上这些类型的控制控制系统和日常生活联系紧密,控制系统是一系列相关的原件在系统运行的基础上相互关联的构成的,此外控制系统存在无人状态下的运行,如飞机自控驾驶,汽车的巡航控制系统?对于控制系统,特别是工业控制系统,我们通常面对的是一系列的器件,自动控制是一个复合型的学科?控制工程师的工作需要具有力学,电子学,机械电子,流体力学,结构学,无料的各方面的知识?计算机在控制策略的执行中具有广泛的应用,并且控制工程的需求带动了信息技术的与软件工程的发展? 通常控制系统的范畴包括开环控制系统与闭环控制系统,两种系统的区别在于是否在系统中加入了闭环反馈装置? 开环控制系统 开环控制系统控制硬件形式很简单,图2.1描述了一个单容液位控制系统, 图2.1单容液位控制系统 我们的控制目标是保持容器的液位h 在水流出流量V 1变化的情况下保持在一定 可接受的范围内,可以通过调节入口流量V 2实现?这个系统不是精确的系统,本系 统无法精确地检测输出流量V 2,输入流量V 1以及容器液位高度?图2.2描述了这 个系统存在的输入(期望的液位)与输出(实际液位)之间的简单关系, 图2.2液位控制系统框图 这种信号流之间的物理关系的描述称为框图?箭头用来描述输入进入系统,以及
Most people can formulate a mental picture of a computer, but computers do so many things and come in such a variety of shapes and sizes that it might seem difficult to distill their common characteristics into an all-purpose definition. At its core, a computer is a device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions. Computer input is whatever is put into a computer system. Input can be supplied by a person, by the environment, or by another computer. Examples of the kinds of input that a computer can accept include the words and symbols in a document, numbers for a calculation, pictures, temperatures from a thermostat, audio signals from a microphone, and instructions from a computer program. An input device, such as a keyboard or mouse, gathers input and transforms it into a series of electronic signals for the computer. In the context of computing, data refers to the symbols that represent facts, objects, and ideas. Computers manipulate data in many ways, and we call this manipulation processing. The series of instructions that tell a computer how to carry out processing tasks is referred to as a computer program, or simply a "program." These programs form the software that sets up a computer to do a specific task. In a computer, most processing takes place in a component called the central processing unit (CPU), which is sometimes described as the"brain" of the computer. A computer stores data so that it will be available for processing. Most computers have more than one location for storing data, depending on how the data is being used. Memory is an area of a computer that temporarily holds data that is waiting to be processed, stored, or output. Storage is the area where data can be left on a permanent basis when it is not immediately needed for processing. Output is the results produced by a computer. Some examples of computer output include reports, documents, music, graphs, and pictures. An output device displays, prints, or transmits the results of processing. Computers are versatile machines, which are able to perform a truly amazing assortment of tasks, but some types of computer are better suited to certain tasks than other types of computers. Computers can be categorized as personal computer, handheld computers, workstations, mainframes, supercomputers , and servers. 大多数人可以制订一个电脑精神的图片，但电脑做很多事情，出现这样的形状和大小不同，它似乎难以提炼成一个全能的定义，它们的共同特点。在其核心，一台计算机是一种装置，它接受输入，处理数据，存储数据，并产生输出，根据对所有存储一系列指示。 什么是计算机输入到计算机系统的压力。输入可提供的一人，由环境，或由另一台计算机。对输入的各种例子，一个计算机可以接受包括文字和符号的文件，规定计算，图片，从恒温器的温度数字，音频信号从一个麦克风，从电脑程序指令。一个输入设备，如键盘或鼠标，集输和转换成一个电子信号的计算机的一系列。 在计算中，数据是指以符号代表的事实，对象和想法。计算机操作在很多方面的数据，我们称之为操作处理。一系列的指令，告诉计算机如何进行处理任务，被称为一个计算机程序，或只是一个“程序”。这些方案形成了软件，建立了计算机做特定的任务。在计算机中，大部分处理发生在一个组件的地方称为中央处理单元（CPU），有时为“大脑的计算机”来形容。 计算机存储数据，以便它会被用作处理可用。大多数计算机有多个用于存储数据的位置，这取决于数据如何被使用。内存是计算机的一个领域，数据是暂时持有等待处理，存储或输出。在数据存储，是可以在一个地区长期离开时，没有立即处理所需。 输出是由电脑产生的结果。电脑输出的一些例子包括报告，文件，音乐，图形，图片。输出设备显示，打印，或传送的处理结果。 电脑是多功能机，它能够执行各种各样的任务十分惊人，但某些类型的计算机更适合比其他类型的计算机的某些任务。计算机可以被归类为个人电脑，掌上电脑，工作站，大型机，超级计算机和服务器。
常用自动化仪表术语中英文对照 自动化仪表 automation instrumentation 测量 measurement 现场 site 控制 control 就地仪表 local instrument 检测仪表 detecting and measuring instrument 传感器 transducer 转换器 converter 变送器 transmitter 执行器 actuator 显示仪表 display instrument 控制仪表 control instrument 检测元件、传感元件 sensor 取源部件 tap 检测点 measuring point 测温点 temperature measuring point 取压点 pressure measuring point 综合控制系统 comprehensive control system 管道 piping 仪表管道 instrumentation piping 测量管道 measuring piping 信号管道 signal piping 气源管道 air piping 电缆槽 cable tray 回路 loop 仪表线路 instrumentation line 保护管 protective tube 伴热 heat tracing 脱脂degreasing 检验 inspection 试验 testing 检定 verification 校准 calibration 调整 adjustment 防爆电气设备 explosion-protected electrical apparatus 爆炸性环境 explosive atmosphere 危险区域 hazardous area
element n、元件，成分node n、节点branch n、分支loop n、回路resistor n、电阻器impedance n、阻抗analog n、模拟digital adj、数字的pulse n、脉冲interface n、接触面，界面decoder n、解码器 transformer n、变压器single-phase 单相pulsate vi、脉动three-phase power三相电源three-phase circuit 三相电路 wye connection 星形连接delta connection 三角形连接phase voltage 相电压line voltage 线电压voltmeter n、电压表ammeter n、电流表clamp-on ammeter钳式安培表 solid-state adj、固态的valve n、真空管，活栓semiconductor n、半导体switching n、开关diode n、二极管inverter n、反向换流器(逆变器) thyristor n、硅可控整流器inverter thyristor 晶闸管逆变器transistor n、晶体管substantial adj、牢固的fluorescent lamp ballast 荧光灯镇流器HVDC transmission system 高压直流输电系统 induction motor 感应电动机rectifier n、整流器 thyratron n、闸流管ignitron n、引燃管，放电管cycloconverter n、循环变流器spectrum n、光谱 wafer n、圆片，晶片chopper n、斩波器polarity n、极性silicon-controlled rectifiers (SCR) n、可控硅整流器 gate turn-off thyristors (GTO) n、门极可关断晶闸管 MOS Controlled Thyristor (MCT) n、MOS控制晶闸管
architecture n. 体系结构 artillery shell 炮弹 conveyor n. 传送带 flip-flop n. 触发器 geothermal adj. 地热的 off-peak adj. 非高峰的 Ohm n. 欧姆 wye n. Y形联结，星形联结，三通 character recognition 文字识别 pattern recognition 模式识别 abound v. 大量存在 accelerate v. 加速 access v. 存取，接近 accessory n. 附件 accommodate v. 容纳，使适应 acoustic adj. 听觉的 acoustic sensor 声传感器，声敏元件 acronym n. 首字母缩写词 active adj. 主动的，有源的 active network 有源网络 actuator n. 执行器 ad hoc 尤其，特定地 address n. 寻址 address generators 地址发生器 adjoint n., adj. 伴随（的），共轭（的） admissible adj. 可采纳的，允许的 advent n. 出现 aerodynamic adj. 空气动力学的 aerodynamics n. 空气动力学，气 体力学 aesthetically adv. 美术地，美学地 aforementioned adj. 上述的，前面 提到的 agility n. 灵活，便捷 agility n. 灵活，便捷 AI 人工智能 air gap 气隙 airgap = air gap 气隙 air-to-close (AC) adj. 气关的 air-to-open (AO) adj. 气开的 albeit conj. 虽然 algebraic equation 代数方程 alignment n. 组合 all-electric range 全电动行驶里程 alleviate v. 减轻，缓和 allowance for finish 加工余量 alloy n. 合金 alnico n. 铝镍钴合金，铝镍钴永 磁合金 aloft adv. 高高地 alphanumeric adj. 字母数字混合 的 alternative n. 可供选择的办法 altitude n. 海拔 aluminum n. 铝 amortisseur n. 阻尼器 amplifier n. 放大器 amplify v. 放大 amplitude n. 振幅 anthropomorphically adv. 拟人地 anti-alias filter 抗混叠滤波器 APICS = American Production and Inventory Control Society 美国生产与 库存管理学会 apparatus n. 一套仪器，装置 approach n. 途径，方法；研究 aptness n. 恰当 arbitrary adj. 任意的 arbitrary adj. 任意的 architecture n. 架构 archive v. 存档 argument n. 辐角，相位 arithmetic-logic unit 算术逻辑部 件 armature n. 电枢，衔铁，加固 arrival angle 入射角 arrival point 汇合点 artificial intelligence 人工智能 ASIC = Application Specific Integrated Circuit 特定用途集成电路 assembly n. 装置，构件 assembly line 装配生产线 assumption n. 假设 asymmetric adj. 不对称的 asymptote n. 渐进线 asymptotically stable 渐近稳定 asynchronous adj. 异步的 asynchronous adj. 异步的 at rest 处于平衡状态 at the most 至多 attached adj. 附加的 attain v. 达到，实现 attenuate v. 减弱 attenuation n. 衰减 attitude n. 姿态 audio adj. 音频的 auto-isolation n. 自动隔离 autonomous adj. 自治的 autonomous adj.自治的，自激的 auto-restoration n. 自动恢复供电 auto-sectionalizing n. 自动分段 auxiliary material 辅助材料 axon n. 轴突 backlash n. 齿隙游移 bandwidth n. 带宽 bar code scanner 条码扫描仪 baud n. 波特 become adept in 熟练 bench mark 基准点 bias n. 偏压 bi-directional adj. 双向的 binary adj. 二进制的 binary-coded adj. 二进制编码的 biomass n. 生物质 biopsy n. 活体检查 bipolar adj. 双向的 BJT 双极结型晶体管 blackout n. （大区域的）停电 BLDM 无刷直流电动机 block diagram algebra 方块图计 算（代数） 1 / 11
In the case of a resistor, the voltage-current relationship is given by Ohm’s law, which states that the voltage across the resistor is equal to the current through the resistor multiplied by the 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。 2]It 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。 Viewed in this light, it will be found that the analysis of three-phase circuits is 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。 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。 It should be noted that if the polarity of point Awith respect to N ( is assumed for the positive half-cycle, then when used in the same phasor diagram should be drawn opposite to, or 180? 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? 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. 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。
Part Ⅴ Sensors and Transmitters In a feedback control system, the elements of a process-control systemare defined interms of separate functional parts of the system . The four basic components of controlsystems are thesensors, transmitter , controller , and final control elements . Thesecomponents per form the three basic operations of every control system: measurementdecision, and action. Sensors and transmitters perform the measurements operation of control system. Thesensor produces a phenomenon, mechanical, or the like related to the process variable that itmeasures. The function of transmitter in turn is to convert the signal from sensor to the formrequired by the final control device. The signal, therefor e, is related to the process variable. Two analog standards are in common u se as a means of representing the range ofvariables in control systems. For electrical systems we use a range of electric current carriedin wires , and for pneumatic systems we use a range of gas pressure carried in pipes . Thesesignals are used primarily to transmitvariable information over some distance, such as to andfrom the control room and the plant .Fig .5 . 9 shows a diagram of a process- controlinstallation where current is used to transmit measurement data about the controlled variableto the control room, and gas pressure in pipes is used to transmit a feedback signal to a valve to change flow as the controlling variable . Fig .5 .9 Electrical current and pneumatic pressures are the most common means of information transmitter in the industrial environment Current signal The most common current transmission signal is 4 to 20 mA . Thu s , in the preceding temperature example, 20℃might be represented by 4 mA, and 120℃by 20 mA, with all temperatures in between represented by a proportional current . The gain is 略 That is , we can say that the gain of sensor/ transmitter is ratio of the span of the output to the span of input . Current is used instead of voltage because the system is then les s dependent on load . Voltage is not used for transmission because of its susceptibility to changes of resistance in the line . Pneumatic signals The most common standard for pneumatic signal transmitter is 3 to 15 psi . In this case, when a sensor measures some variable in a range it is converted into a proportionalpressure of gas in a pipe . The gas is usually dry air .The pipe may be many hundreds of meters long , but as long as there is no leak in the system the pressure will be propagated down the pipe . This English system standard is still widely used in the U .S ., despite the move to the SI system of units . The equivalent SI range that will eventually be adopted is 20 to 100 kPa. The two cases presented show that the gain of the sensor/ transmitter is constant over its completeoperating range . For most sensor/ transmitter this is the case; however , there are some in stances , such as a differential pressure sensor used to measure flow, when this is not the case . A differential pressure sensor measures the differential pressure ,h, across an orifice . This differential pressure is related to the square of the volumetric flow rate F . That is F2 ah . The equation that describes the output signal form an electronicdifferential pressure transmitter when used to measure volumetric flow with a range of 0～F maxgpm is
第一章第一篇sectiong Two variables u(t) and i(t) are the most basic concepts in an electric circuit, they characterize the various relationships in an electric circuitu(t)和i(t)这两个变量是电路中最基本的两个变量，它们刻划了电路的各种关系。 Charge and Current The concept of electric charge is the underlying principle for explaining all electrical phenomena. Also, the most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter consists, measured in coulombs (C). 电荷和电流电荷的概念是用来解释所有电气现象的基本概念。也即，电路中最基本的量是电荷。电荷是构成物质的原子微粒的电气属性，它是以库仑为单位来度量的。 We know from elementary physics that all matter is made of fundamental building blocks known as atoms and that each atom consists of electrons, protons, and neutrons. We also know that the charge e on an electron is negative and equal in magnitude to 1.60210×10-19C, while a proton carries a positive charge of the same magnitude as the electron. The presence of equal numbers of protons and electrons leaves an atom neutrally charged. 我们从基础物理得知一切物质是由被称为原子的基本构造
《自动化专业英语教程》-王宏文主编-全文翻译 PART 1Electrical and Electronic Engineering Basics UNIT 1A Electrical Networks ————————————3 B Three-phase Circuits UNIT 2A The Operational Amplifier ———————————5 B Transistors UNIT 3A Logical Variables and Flip-flop ——————————8 B Binary Number System UNIT 4A Power Semiconductor Devices ——————————11 B Power Electronic Converters UNIT 5A Types of DC Motors —————————————15 B Closed-loop Control of D C Drivers UNIT 6A AC Machines ———————————————19 B Induction Motor Drive UNIT 7A Electric Power System ————————————22 B Power System Automation PART 2Control Theory UNIT 1A The World of Control ————————————27 B The Transfer Function and the Laplace Transformation —————29 UNIT 2A Stability and the Time Response —————————30 B Steady State—————————————————31 UNIT 3A The Root Locus —————————————32 B The Frequency Response Methods: Nyquist Diagrams —————33 UNIT 4A The Frequency Response Methods: Bode Piots —————34 B Nonlinear Control System 37 UNIT 5 A Introduction to Modern Control Theory 38 B State Equations 40 UNIT 6 A Controllability, Observability, and Stability B Optimum Control Systems UNIT 7 A Conventional and Intelligent Control B Artificial Neural Network PART 3 Computer Control Technology UNIT 1 A Computer Structure and Function 42 B Fundamentals of Computer and Networks 43 UNIT 2 A Interfaces to External Signals and Devices 44 B The Applications of Computers 46 UNIT 3 A PLC Overview B PACs for Industrial Control, the Future of Control