Text A
Simple Electric Circuit
1. An Electric Circuit
　　A fundamental relationship exists between current, voltage, and resistance. A simple electric circuit consists of a voltage source, some type of load, and a conductor to allow electrons to flow between the voltage source and the load.[1] In the following circuit a battery provides the voltage source, electrical wire is used for the conductor, and a light provides the resistance (see Figure 3-1). An additional component has been added to this circuit, a switch. There must be a complete path for current to flow. If the switch is open, the path is incomplete and the light will not       illuminate. Closing the switch completes the path, allowing electrons to leave the negative      terminal and flow through the light to the positive terminal. 

Figure 3-1  A simple electric circuit
2. An Electrical Circuit Schematic
　　The following schematic is a representation of an electrical circuit, consisting of a battery, a resistor, a voltmeter and an ammeter (see Figure 3-2). The ammeter, connected in series with the circuit, will show how much current flows in the circuit. The voltmeter, connected across the voltage source, will show the value of voltage supplied from the battery. Before an analysis can be made of a circuit, we need to understand Ohm’s Law.
3. Ohm’s Law
　　The relationship between current, voltage and resistance was studied by the 19th century 


Figure 3-2  A representation of an electrical circuit
German mathematician, Georg Simon Ohm. Ohm formulated a law which states that current   varies directly with voltage and inversely with resistance. From this law the following formula is derived:
	 or 
　　Ohm’s law is the basic formula used in all electrical circuits. Electrical designers must   decide how much voltage is needed for a given load, such as computers, clocks, lamps and  motors. Decisions must be made concerning the relationship of current, voltage and resistance. All electrical design and analysis begins with Ohm’s law. There are three mathematical ways to express Ohm’s law. Which of the formulas is used depends on what facts are known before  starting and what facts need to be known.
	    
4. Ohm’s Law Triangle
　　There is an easy way to remember which formula to use. By arranging current, voltage and resistance in a triangle, one can quickly determine the correct formula (see Figure 3-3).

Figure 3-3  Ohm’s law triangle
5. Using the Triangle
　　To use the triangle, cover the value you want to calculate. The remaining letters make up the formula (see Figure 3-4).[2]

Figure 3-4  Forms of Ohm’s law triangle
　　Ohm’s law can only give the correct answer when the correct values are used. Remember the following three rules:
　　(1) Current is always expressed in amperes or amp.
　　(2) Voltage is always expressed in volt.
　　(3) Resistance is always expressed in ohm.
6. Resistance in a Series Circuit
　　A series circuit is formed when a number of resistors are connected end-to-end so that there is only one path for current to flow.[3] The resistors can be actual resistors or other devices that have resistance. The illustration shows four resistors connected end-to-end (see Figure 3-5). There is one path of electron flow from the negative terminal of the battery through R4, R3, R2, R1 returning to the positive terminal. 

Figure 3-5  Resistance in a series circuit
7. Formula for Series Resistance
　　The values of resistance add in a series circuit (see Figure 3-6). If a 4? resistor is placed in series with a 6? resistor, the total value will be 10?. This is true when other types of resistive devices are placed in series. The mathematical formula for resistance in series is
Rt = R1 + R2 + R3 + R4 + R5

Figure 3-6  The values of resistance add in a series circuit
　　Given a series circuit where R1 is 11k?, R2 is 2k?, R3 is 2k?, R4 is 100?, and R5 is 1k?, what is the total resistance?   
                     Rt = R1 + R2 + R3 + R4 + R5
                       = (11 000 + 2000 + 2000 + 100 + 1000)?
                       = 16 100?
8. Current in a Series Circuit
　　The equation for total resistance in a series circuit allows us to simplify a circuit (see Figure 3-7). Using Ohm’s law, the value of current can be calculated. Current is the same anywhere it is measured in a series circuit. 
	
　　　　　　　　　　　　　　　　　　　　A
　　　　　　　　　　　　　　　　　　　　

Figure 3-7  Original circuit and equivalent circuit
9. Voltage in a Series Circuit
　　Voltage can be measured across each of the resistors in a circuit. The voltage across a resistor is referred to as a voltage drop. A German physicist, Kirchhoff, formulated a law which states the sum of the voltage drops across the resistances of a closed circuit equals the total voltage applied to the circuit.[4] In the following illustration, four equal value resistors of 1.5? each have been placed in series with a 12V battery (see Figure 3-8). Ohm’s law can be applied to show that each resistor will “drop” an equal amount of voltage. 

Figure 3-8  Voltage in a series circuit
　　First, solve for total resistance:
Rt = R1 + R2 + R3 + R4 = (1.5 + 1.5 + 1.5 + 1.5) ??= 6?
　　Second, solve for current:
	
　　　　　　　　　　　　　　　　　　　　A
　　　　　　　　　　　　　　　　　　　　
　　Third, solve for voltage across any resistor:
	U = I×R
　　　　　　　　　　　　　　　　　　　= (2×1.5)V
　　　　　　　　　　　　　　　　　　　= 3V
　　If voltages were measured across any single resistor, the voltmeter would read 3V.[5] If  voltage were measured across a combination of R3 and R4 the voltmeter would read 6V. If voltage were measured across a combination of R2, R3, and R4 the voltmeter would read 9V. If the voltage drops of all four resistors were added together the sum would be 12V, the original supply voltage of the battery.
10. Voltage Division in a Series Circuit
　　It is often desirable to use a voltage potential that is lower than the supply voltage. To do this, a voltage divider can be used (see Figure 3-9). The battery represents UI which in this case is 50V. The desired voltage is represented by UO which mathematically works out to be 40V. To calculate this voltage, first solve for total resistance:
	Rt = R1 + R2
                                     = (5 + 20)?
                                     = 25?

Figure 3-9  Voltage division in a series circuit
　　Second, solve for current:
	
　　　　　　　　　　　　　　　　　　　　A
　　　　　　　　　　　　　　　　　　　　
　　Finally, solve for voltage:
	UO = I?×R2
　　　　　　　　　　　　　　　　　　　= (2×20)V
　　　　　　　　　　　　　　　　　　　= 40V
New Words
circuit
[(s((k(t]
n. 电路；一圈，周游，巡回
fundamental
[(f(nd((mentl] 
adj. 基础的，基本的
load
[l((d] 
n. 负荷，负载，加载
battery
[(b(t(r(] 
n. 电池
component
[k(m(p((n(nt] 
n. 成分
switch
[sw(t(] 
n. 开关，电闸；转换
illuminate
[((lu(m(ne(t] 
vt. 阐明，说明（问题等）；启发，启蒙
negative
[(ne((t(v] 
adj. 阴性的，负的；否定的，消极的
n. 否定，负数
vt. 否定，拒绝（接受）
positive
[(p?z(t(v]
adj. 阳的，带正电的；肯定的，积极的，确实的；[数]正的
schematic
[ski((m(t(k]
adj. 示意性的
voltmeter
[(v((ltmi(t(]
n. 电压表
ammeter
[((mi(t(]
n. 电流表
mathematician
[(m(((m((t((n]
n. 数学家
vary
[(ve(r(]
vt. 改变，变更；使多样化
vi. 变化，不同；违反
inverse
[((n(v((s] 
adv. 相反地，倒转地
derive
[d((ra(v]
v.（使）起源于，来自; 获得
designer
[d((za(n(]
n. 设计者，设计师
lamp
[l(mp]
n. 灯
relationship
[r((le((n((p]
n. 关系，关联
analysis
[((n(l(s(s]
n. 分析，分解
triangle
[(tra((((l]
n. 三角形
calculate
[(k(lkjule(t]
vt. & vi. 计算；考虑，计划，打算
vt. & vi.（美）以为，认为
equation
[((kwe((n] 
n. 相等，平衡；因素；方程式，等式
meter
[(mi(t(] 
n. 仪表，计，表；米 
divider
[d((va(d(]
n. 分割者；间隔物，分配器
Phrases
electric circuit
电路
consist of
由……组成，包括，包含
be used for
用来做……，被用于
make up 
组成，构成
series circuit
串联电路
series resistance
串联电阻
electron flow
电流
be placed in
被放置在
be referable to
可归因于，与……有关
voltage drop
电压降
solve for
求解
supply voltage
供电电压，电源电压
voltage potential
电压电位
Notes
　　[1] A simple electric circuit consists of a voltage source, some type of load, and a conductor to allow electrons to flow between the voltage source and the load.
　　本句中的谓语动词是consist of，意为“由……组成，包括，包含”。to allow electrons to flow between the voltage source and the load是一个动词不定式短语，作定语，修饰和限定a conductor，表明是什么样的导线，而不是整个句子。
　　本句意为：一个简单的电路包括电源、某些类型的负载和一条让电子在电源和负载之间流动的导线。
　　[2] To use the triangle, cover the value you want to calculate. The remaining letters make up the formula.
　　这两个句子关系紧密，要联系起来理解。后一个句子表明的是使用三角形，盖住要计算的值的结果，剩下的字母组成公式。To use the triangle是一个动词不定式短语，作目的状语，修饰cover。you want to calculate是一个定语从句，修饰和限定the value。make up的意思是“组成，构成”。
　　本句意为：要利用这个三角形，盖住你想要计算的值。用剩下的字符组成公式。
　　[3] A series circuit is formed when a number of resistors are connected end-to-end so that there is only one path for current to flow.
　　本句中的end-to-end不能凭字面理解为尾对尾，而是首尾相连的意思。so that there is only one path for current to flow是一个结果状语从句。when a number of resistors are   connected end-to-end是一个条件状语从句。
　　本句意为：当多个电阻首尾相连，电流只有一条路径流动时，就形成了串联电路。
　　[4] A German physicist, Kirchhoff , formulated a law which states the sum of the voltage drops across the resistances of a closed circuit equals the total voltage applied to the circuit.
　　看懂这个句子的关键是分析它的句子结构。这是一个多层从句的句子。全句的主语是A German physicist，谓语是formulated，宾语是a law，Kirchhoff是同位语。which引导的定语从句修饰a law。在该定语从句中，which作主语，states是谓语动词，states后又是一个宾语从句，省略了引导词that。在这个宾语从句中，主语为the sum of the voltage drops，谓语为equals，宾语为the total voltage。结构清楚后，整个句子的意思就一目了然了。
　　本句意为：德国物理学家基尔霍夫提出了一个定律为，整个回路中各个电阻器上的电压降的总和等于给这个回路提供的电压。
　　[5] If voltage were measured across any single resistor, the voltmeter would read 3V.
　　注意，“表的读数为……”的表达是本句中的voltmeter would read，而不是voltmeter would be read。read 应理解“显示，指示”。例如，The dial reads 32. 刻度显示出32。
　　本句意为：如果测量任何单个电阻器上的电压，电压表的读数都会是3V。
Exercises
【Ex.1】根据课文内容，回答以下问题。
1. What does Ohm’s law state? 
 

2. According to the passage, how to use the triangle?
 

3. What is a series circuit?
 

4. How do we measure the voltage drop of each of the resistors in a circuit?
 

5. If three resistors of 10?, 20? and 30? respectively have been placed in series with a 12V battery, what is the voltage drop of each of the resistors in a circuit?
　　
　　 
【Ex.2】根据下面的英文解释，写出相应的英文词汇。
英 文 解 释
词    汇
a closed path followed or capable of being followed by an electric current

a device used to break or open an electric circuit or to divert current from one conductor to another

a position in a circuit or device at which a connection is normally established or broken

an instrument, such as a galvanometer, for measuring potential differences in volts

an instrument that measures electric current

a device that generates light, heat, or therapeutic radiation

a device that converts any form of energy into mechanical energy, especially an internal-combustion engine or an arrangement of coils and magnets that converts electric current into mechanical power

a person who does research connected with physics or who studies physics.

the difference in voltage between two points in an electric field or circuit

a device that measures and records the amount of electricity, gas, water, etc. that you have used or the time and distance you have travelled, etc

　　
【Ex.3】把下列句子翻译成中文。
1. A power supply could be something as simple as a 9V battery or it could be as complex as a precision laboratory power supply.
 



2. Variable resistors have a dial or a knob that allows you to change the resistance. 
 

3. Diodes are components that allow current to flow in only one direction.  


4. LEDs use a special material which emits light when current flows through it.  
 

5. The letter L stands for inductance. The simplest inductor consists of a piece of wire.
 

6. Two metallic plates separated by a non-conducting material between them make a simple  capacitor.
 

7. The time required for a capacitor to reach its charge is proportional to the capacitance value and the resistance value. 
 

8. When AC current flows through an inductance a back emf or voltage is generated to prevent changes in the initial current. 
	 

9. Reactance is the property of resisting or impeding the flow of AC current or AC voltage in inductors and capacitors.
 

10. To produce a drift of electrons, or electric current, along a wire it is necessary that there be a difference in “pressure” or potential between the two ends of the wire.  
 
　　
【Ex.4】把下列短文翻译成中文。
　　Switches are devices that create a short circuit or an open circuit depending on the position of the switch. For a light switch, ON means short circuit (current flows through the switch, lights light up). When the switch is OFF, that means there is an open circuit (no current flows, lights go out). When the switch is ON it looks and acts like a wire. When the switch is OFF there is no connection.


【Ex.5】通过Internet查找资料，借助电子词典、辅助翻译软件及AI工具，完成以下技术报告，并附上收集资料的网址。通过E-mail发送给老师，或按照教学要求在网上课堂提交。
1. 一个电路包括哪些主要元件，各种元件由哪些公司生产（附各种最新产品的图片）。
2. 叙述德国物理学家基尔霍夫的生平简历及其重大贡献。
Text B
DC Parallel Circuit
1. Resistance in a Parallel Circuit
　　A parallel circuit is formed when two or more resistances are placed in a circuit side-by-side so that current can flow through more than one path. The illustration shows two resistors placed side-by-side (see Figure 3-10). There are two paths of current flow. One path is from the negative terminal of the battery through R1 returning to the positive terminal. The second path is from the negative terminal of the battery through R2 returning to the positive terminal of the battery.  

Figure 3-10  Resistance in a parallel circuit
2. Formula for Equal Value Resistors in a Parallel Circuit
　　To determine the total resistance when resistors are of equal value in a parallel circuit, use the following formula:
	
　　In the following illustration there are three 15? resistors (see Figure 3-11). The total       resistance is
	
                               Ω
　　　　　　　　　　　　　　　

Figure 3-11  Equal value resistors in a parallel circuit
3. Formula for Unequal Resistors in a Parallel Circuit
　　There are two formulas to determine total resistance for unequal value resistors in a parallel circuit. The first formula is used when there are three or more resistors. The formula can be  extended for any number of resistors. The following is an example of three resistors.
	
　　In the following illustration there are three resistors (see Figure 3-12). each of different  value. The total resistance is
	
　　　　　　　　　　		Insert value of the resistors
                       		Find lowest common multiple
                                 	Add the numerators
　　　　　　　　　　    			Invert both sides of the equation
                     Rt ≈ 2.86?    		Divide

Figure 3-12  The total resistance when there are three resistors
　　The second formula is used when there are only two resistors.
	
　　In the following illustration there are two resistors (see Figure 3-13), each of different value. The total resistance is
   	
                                       
                                       Ω
                                       

Figure 3-13  The total resistance when there are only two resistors
4. Voltage in a Parallel Circuit
　　When resistors are placed in parallel across a voltage source, the voltage is the same across each resistor. In the following illustration three resistors are placed in parallel across a 12V  battery (see Figure 3-14). Each resistor has 12V available to it. 

Figure 3-14  Voltage in a parallel circuit
5. Current in a Parallel Circuit
　　Current flowing through a parallel circuit divides and flows through each branch of the  circuit (see Figure 3-15).

Figure 3-15  Current in a parallel circuit
　　Total current in a parallel circuit is equal to the sum of the current in each branch. The  following formula applies to current in a parallel circuit
	
6. Current Flow with Equal Value Resistors in a Parallel Circuit
　　When equal resistances are placed in a parallel circuit, opposition to current flow is the same in each branch. In the following circuit R1 and R2 are of equal value (see Figure 3-16). If total current (It) is 10A, then 5A would flow through R1 and 5A would flow through R2. 
	
                                       
                                       

Figure 3-16  Current flow with equal value resistors in a parallel circuit
7. Current Flow with Unequal Value Resistors in a Parallel Circuit
　　When unequal value resistors are placed in a parallel circuit, opposition to current flow is not the same in every circuit branch. Current is greater through the path of least resistance. In the following circuit R1 is 40? and R2 is 20??(see Figure 3-17). Small values of resistance means less opposition to current flow. More current will flow through R2 than R1. 

Figure 3-17  Current flow with unequal value resistors in a parallel circuit
　　Using Ohm’s law, the total current for each circuit can be calculated.
	 
　　　　　　　　　　　　　　　　　　　　A
　　　　　　　　　　　　　　　　　　　　
	 
　　　　　　　　　　　　　　　　　　　　A 
　　　　　　　　　　　　　　　　　　　　
	
                                       
                                       
　　Total current can also be calculated by the first calculating total resistance, then applying the formula for Ohm’s law.
	
                                       
                                       
                                       
	
　　　　　　　　　　　　　　　　　　　　A
　　　　　　　　　　　　　　　　　　　　	
8. Series-parallel Circuit
　　Series-parallel circuit is also known as compound circuit. At least three resistors are     required to form a series-parallel circuit. The following illustrations show two ways a       series-parallel circuit could be found (see Figure 3-18). 

Figure 3-18  Series-parallel circuit
9. Simplifying a Series-parallel Circuit to a Series Circuit
　　The formulas required for solving current, voltage and resistance problems have already been defined. To solve a series-parallel circuit, reduce the compound circuits to equivalent simple circuits. In the following illustration R1 and R2 are parallel with each other (see Figure 3-19). R3 is in series with the parallel circuit of R1 and R2. 

Figure 3-19  The compound circuits


　　First, use the formula to determine total resistance of a parallel circuit to find the total       resistance of R1 and R2. When the resistors in a parallel circuit are equal, the following formula is used:
	
　　　　　　　　　　　　　　
　　　　　　　　　　　　　　
　　Second, redraw the circuit showing the equivalent values. The result is a simple series  circuit which uses already learned equations and methods of problem solving (see Figure 3-20).

Figure 3-20  Simplifying a series-parallel circuit to a series circuit
10. Simplifying a Series-parallel Circuit to a Parallel Circuit
　　In the following illustration R1 and R2 are in series with each other (see Figure 3-21). R3 is in parallel with the series circuit of R1 and R2. 

Figure 3-21  A series-parallel circuit
　　First, use the formula to determine total resistance of a series circuit to find the total      resistance of R1 and R2. The following formula is used:
	
　　　　　　　　　　　　　　　　　　　
　　　　　　　　　　　　　　　　　　　
　　Second, redraw the circuit showing the equivalent values. The result is a simple parallel circuit which uses already learned equations and methods of problem solving.
New Words
side-by-side
['sa(d ba( sa(d]
adj. 并排的，并行的
multiple
[(m(lt(pl] 

n. 倍数，若干
adj. 多重的，多个的
numerator
[(nju(m(re(t(]
n.（分数中的）分子
invert
[(n(v((t] 
adj. 转化的
vt. 使颠倒，使转化
n. 颠倒的事物
amp
[(mp] 
n. 安培
branch
[br((nt(] 
n. 枝，分支，支流，支脉
compound
[(k?mpa(nd] 
n. 混合物，[化]化合物
adj. 复合的
vt. & vi. 混合，配合
simplify
[(s(mpl(fa(]
vt. 单一化，简单化
reduce
[r((dju(s] 
vt. 减少，缩小，简化；还原
method
[(me((d]
n. 方法
redraw
[(ri((dr((] 
vt. 重画
vi. 刷新（屏幕）
Phrases
parallel circuit
并联电路
negative terminal
负极端
positive terminal
正极端
lowest common multiple
最小公倍数
apply to
将……应用于
flow through
流过
be calculated by ...
用……计算
series-parallel
串-并联
compound circuits
复合电路
parallel branch
并联分支
Exercises
【Ex.6】根据文章所提供的信息判断正误。
1. A parallel circuit is formed when two or more resistances are placed in a circuit side-by-side so that current can flow through only one path. 
2. To determine the total resistance when resistors are of equal value in a parallel circuit, use the following formula
	    
3. In the following illustration there are three 15Ω resistors. The total resistance is 45Ω.


4. In the following illustration there are three resistors, each of different value. The total      resistance is
	
    

5. When resistors are placed in series across a voltage source, the voltage is the same across each resistor.
6. Current flowing through a parallel circuit divides and flows through each branch of the circuit. Total current in a parallel circuit is equal to the sum of the current in each branch. 
7. When different resistances are placed in a parallel circuit, opposition to current flow is the same in each branch. 
8. Series-parallel circuit is also known as compound circuits. At least more than two resistors are required to form a series-parallel circuit. 
9. In the following illustration R1 and R2 are series with each other. R3 is in parallel with the  series circuit of R1 and R2.


10. In the following illustration, the total resistance is 105Ω.



　　
科技英语翻译知识
词义的引申
　　科技英语论理准确，所下的定义、定律和定理精确，所描绘的概念、叙述的生产工艺过程清楚。但是在英译汉时，经常会出现某些词在字典上找不到适当的词义的情况。如果生搬硬套，译文则生硬晦涩，不能确切表达原意，甚至有时造成误译。这时就要结合上下文，根据逻辑关系，进行词义引申，才能恰如其分地表达原意。
??1．概括化或抽象化引申
　　科技英语常常使用表示具体形象的词来表示抽象的意义。翻译这类词时，一般可将其词义作概括化或抽象化的引申，译文才符合汉语习惯，流畅、自然。例如：
　　(1) The plan for launching the man-made satellite still lies on the table.
　　那项发射人造卫星的计划仍被搁置，无法执行。
　　on the table按字面意思译成“放在桌子上”语义不通，根据上文意思抽象引申为“无法执行”，符合原意。
　　(2) Military strategy may bear some similarity to the chessboard but it is dangerous to carry the analogy too far. 
　　打仗的策略同下棋可能有某些相似之处，但是如果把这两者之间的类比搞过了头则是危险的。
　　chessboard是“棋盘”。棋盘是实物，打仗的策略是思想，不好类比。因此，这里把具体的“棋盘”引申为概括性的“下棋”，就说得通了。
　　(3) The book is too high-powered for technician in general.
　　这本书对一般技术人员来说也许内容太深。
　　high-powered本意为“马力大”，引申为“（艰）深”。
　　(4) The expense of such an instrument has discouraged its use.
　　这种仪器很昂贵，使其应用受到了限制。
　　expense原意为花费、开支，引申为“（仪器）昂贵”。
　　(5) Industrialization and environmental degradation seem to go hand in hand.
　　工业化发展似乎伴随着环境的退化。
　　hand in hand 原意为“携手”，引申为“伴随”。
??2．具体化或形象化引申
　　科技英语中有时用代表抽象概念或属性的词来表示一种具体事物。如按字面译，则难以准确表达原文意思。这时就要根据上下文对词义加以引申，用具体或形象化的词语表达。例如：
　　(1) Along the equator it reaches nearly halfway around the globe.
　　它沿着赤道几乎绕地球半周。
　　reach halfway意为“达到一半路程”。本句讨论的是围绕地球旋转，根据这一具体语境，可以将reach halfway本来含义形象化地引申为“绕地球半周”。
　　(2) The shortest distance between raw material and a finished part is precision casting.
　　把原料加工成成品的最简便的方法是精密铸造。
　　shortest distance原意为“最短距离”，直接按照这一字面意思，句子有失通顺。可以形象化地引申为“最简便的方法”。
　　(3) The foresight and coverage shown by the inventor of the process are most commendable.
　　这种方法的发明者所表现的远见卓识和渊博知识，给人以良好的印象。
　　coverage 原意为“覆盖”，引申为“渊博知识”。
　　(4) The purpose of a driller is to cut holes.
　　钻床的功能是钻孔。
　　purpose原意为“目的”，引申为“功能”。
　　(5) There are many things that should be considered in determining cutting speed. 
　　在测定切削速度时，应当考虑许多因素。
　　things原意为“事情”，具体引申为“因素”。
Reading Material
　　阅读下列文章。
Text
NoteOrCAD View
1. Full-Featured Schematic Editor
　　OrCAD Capture, a flat[1] and hierarchical Schematic Page  Editor, is based on OrCAD’s legacy of fast, intuitive[2] schematic editing. Schematic Page Editor combines a standard Windows user interface with functionality and features specific to the design   engineer for accomplishing design tasks and publishing design data.
　　(1) Undo and redo schematic edit unlimited times.
　　(2) Use Label State for “what if” scenarios[3].
　　(3) Launch Property Spreadsheet Editor at design or schematic level to edit or print your design properties.
　　(4) View and edit multiple schematic designs in a single session.
　　(5) Reuse design data by copying and pasting within or between schematics.
　　(6) Select parts from a comprehensive[4] set of functional part  libraries.
　　(7) In-line editing of parts to allow pin name and number movement.
(8) File locking in case the design is being open by another user.
2. OrCAD Capture
　　OrCAD Capture? design entry is the most widely used schematic entry system in electronic design today for one simple reason: fast and universal design entry. Whether you’re designing a new analog circuit, revising schematic diagram for an existing PCB[5], or designing a digital block diagram with an HDL module, OrCAD Capture provides simple schematic commands you need to enter, modify and verify the design for PCB.
　　(1) Place, move, drag, rotate, or mirror individual parts or grouped selections while preserving both visual and electrical   connectivity[6].
　　(2) Ensure design integrity through configurable Design and Electrical Rule checkers.
　　(3) Create custom title blocks and drawing borders to meet the most exacting specifications.
　　(4) Insert drawing objects, bookmarks, logos[7] and bitmapped pictures.
　　(5) Choose from metric or imperial[8] unit grid spacing to meet all drawing standards.
(6) Design digital circuits with VHDL or Verilog Text Editor.
　　Find and select parts or nets quickly from the OrCAD Capture Project Manager and the multi-window interface makes navigation[9] across hierarchy a breeze.
3. Project Manager Coordinates Design Data
　　The sophisticated[10] Project Manager simplifies organizing and tracking the various types of data generated in the design process.
　　An expanding-tree diagram makes it easy to structure and    navigate all of your design files, including those generated by PSpice? simulators, Capture CIS and other plug-ins.
　　(1) Project Creation Wizard guides you through all the resources available for a specific design flow.
　　(2)?Centralized management of all design data permits a  seamless[11] interchange of schematic data for OrCAD plug-ins and downstream flow.
　　(3) Hierarchy browser lets you navigate the entire schematic structure and open specific elements whether it’s a schematic page, a part, or net—instantly.
　　(4) File tab groups multi-page schematics in folders for flat  designs and creates new folders automatically for added levels of hierarchical[12] designs.
　　(5) Archive capability ensures the portability[13] of your entire design project.
4. Hierarchical Design and Reuse
　　OrCAD Capture boosts[14] schematic editing efficiency by enabling you to reuse subcircuits[15] without having to make multiple copies. Instead, using hierarchical blocks, you can simply reference the same subcircuit multiple times.
　　(1) Enable a single instance of the circuitry[16] for you to create, duplicate and maintain. 
　　(2) Automatic creation of hierarchical ports eliminates potential design connection errors.
　　(3) Update ports and pins dynamically for hierarchical blocks and underlying schematics.
　　(4) Reuse OrCAD Layout and Cadence? Allegro? high-speed PCB modules within or between schematics.
　　(5) Require just one instance of the circuitry for you to create and maintain.
　　(6) Unlimited referencing and reuse of circuitry throughout your entire design.
(7)?Serve schematic pages from library files.
　　(8)?Sophisticated Property Editor clearly distinguishes[17] properties in a subcircuit from those in referenced uses allowing you to view and edit from one place.
5. Libraries And Part Editor
　　You can access Library Editor directly from the OrCAD Capture user interface. Create and edit parts in the library or directly from the schematic page without interrupting your workflow.
　　(1) Movable pin name and pin number.
　　(2) Intuitive graphical controls speed of schematic part creation and editing.
(3)?Create new parts quickly by modifying existing ones.
　　(4)?Spreadsheet[18] and pin array utilities make short work of creating and editing pin-intensive devices.
(5) Bused vector pins reduce clutter on schematics.
　　(6) Create FPGA and CPLD symbols quickly and easily with Part Generator. Compatible with ten popular places and route pin reports.
(7) Drag-and-drop parts between libraries.
　　(8) Speed creation and maintenance of master library sets with design cache.
　　(9) Revise a part in the original subcircuit only, or propagate[19] the change to all other uses of the subcircuit in the design.
　　(10)?Capability to add or delete sections of multisection[20]  homogeneous/heterogeneous parts.
　　(11) Control power and ground pin visibility and connectivity on a per-schematic basis.
6. Integrate Huge I/O Count FPGA And CPLD
　　OrCAD Capture provides a Library Part Generator to automate the integration of FPGA and PLD[21] devices into your system schematic. The Generate Part feature simplifies the creating of core FPGA  library parts for devices that might have many hundreds of pins.   Signal placement reports created by popular FPGA design applications like those from Altera, Actel, and Xilinx are read into Generate Part to design the core Capture symbol saving up the hours of tedious graphical entry work. OrCAD Capture supports Xilinx 4.1i/4.2iPAD file format. If, during the PCB layout phase, the PCB designer   discovers a more efficient pin placement scheme for the package or additional functionality[22] is added to the FPGA or PLD, the system engineer must modify the symbol and schematics to reflect this change which is error prone and may cause designs to be out of sync. The Generate Part feature has an annotate[23] option which modifies an existing symbol with new pin assignments.
　　Step 1: Creating parts with potentially hundreds of pins is an error prone and painstaking task. With Generate Part you simply browse in the pin and signal report file created by your place and route software.
　　Step 2: Specify to create a new part or update an existing one. Packages of all kinds are supported including PGAs and BGAs.
　　Step 3: The new part is created fast. Pins with common names are intelligently[24] grouped and ordered.
7. Easy Entry Of Part, Pin, And Net Data
　　Access all part, net, pin, and title block properties, or any subset, and make changes quickly through the OrCAD Capture spreadsheet Property Editor.
　　(1) Select a circuit element, grouped area, or entire page then add/ edit/delete part, net, or pin properties.
　　(2)?Globally apply specific property names across all your   designs to meet your particular netlist[25] or other output requirements. This maintains consistency, reduces manual errors, and eliminates multiple re-entry.
　　(3) Browse and instantly visit any part, net, hierarchical port, off page connector, bookmark, or design rule error marker from a single reference point.
8. Verify Circuits Early With Design Rule Check
　　The configurable Design Rule Check (DRC) feature in OrCAD Capture allows a comprehensive verification of your design before committing[26] to downstream design processes saving the time and cost of ECOs latter in the design cycle.
(1) Report duplicate parts.
(2) Identify invalid design packaging.
(3) Detect off-grid objects leading to unconnected signals.
　　(4)?Configure with electrical violations to report and assign  severity[27]warnings.
(5) Check entire design or specific modules.
9. Reports
　　OrCAD Capture creates basic bill of materials (BOMs) outputs extracting from the information contained in the schematic database.
　　(1) Extract all part properties in the schematic design and output them to a text file.
　　(2) Automatically package parts with reference designators prior to report generation.
10. Part Selection
　　While placing a component, you can identify it visually, modify the properties as needed, then dynamically place it within a design—all in the same sequence.
　　(1) Zero-in quickly on the exact library part you want, using wildcard[28] searches.
　　(2) Pick your recent part choices from the most recently used (MRU) menu.
(3) Choose a logic gate or DeMorgan equivalent.
(4) Edit schematic parts graphically prior to placement.
(5) Add, modify, and delete part properties at any time.
　　(6) Place previously used parts fast by grabbing them from the project design cache.
　　(7) Automatically assign reference designators during or after part placement. Update all, or just unidentified[29] parts, or reset all to placeholder values.
　　(8) Add libraries to a project from any drive or directory without leaving the part selector.
　　(9) Apart filter[30] can be used to filter out the parts from existing libraries based on parameters like HDL models, Spice models, etc. associated with symbols.
11. Interface Capabilities
　　OrCAD Capture interfaces with other CAD applications with minimal[31] translation needs or integration problems by importing and exporting virtually every commonly used design file format.
(1) Export of DXF files to AutoCAD?.
(2) View and redline schematic with MYRIAD?.
　　(3) Bi-directional EDIF 200 graphic transfer and export of the EDIF 200 netlist format.
　　(4) Import MicroSim? schematic.
　　(5) Export of more than 30 netlist formats, including VHDL, Verilog?, PSpice, SPICE, and PADS 4.0.
　　(6) Interface with OrCAD Layout and Allegro PCB with forward and back annotation.
　　(7) Interface with NC VHDL Desktop and Synplicity Synplify? for FPGA design.
　　(8) Interface with NC VHDL Desktop and NC Verilog? Desktop for board level (multi-chips) digital simulation[32].
(9) Creation of custom netlists using Microsoft Visual BASIC.
12. Printing and Plotting
　　Produce professional hardcopy through any output device  supported by Microsoft Windows.
(1) Print Area prints specific area of the design in larger scale.
(2) Print Preview ensures proper scale and orientation[33].
(3) Export to the DXF format for CAD interchange.
　　(4)?Cross-probing[34] between OrCAD Capture and Cadence  Allegro PCB Layout.


[1] adj. 平面的 
[2] adj. 直觉的




[3] n. 情况





[4] adj. 全面的，广
泛的








[5]?Printed Circuit 
Board，印制电路板




[6] n. 连通性




[7] n. 标识

[8] adj. 英制的（度
量衡）


[9] n. 向导，导航



[10] adj. 先进的，精妙的