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1、电线电缆光纡技术文件 Wire, Cable, and Fiber Optics 电线，电缆，及光纤 Basic constructions 基础建设 Wire and cable consists, for the most part, of four basic constructions:电线和电缆组成，大部份的四个基本建设： Single conductor单导体 o One conductor, bare or insulated.一导体，裸或绝缘。 Multiconductor多导体 o Multiple insulated wires多重绝缘电线 Twisted pairs扭曲的
2、对 o Two insulated wires usually twisted together 2绝缘电线，通常扭曲在一起 Coaxial cable同轴电缆 o Insulated center conductor with a shield and jacket overall.绝缘中心导体与屏蔽层及护套的整体。 Solid and Stranded 固体和滞留 Conductors come in two variations, solid and stranded.指挥家来了两个变化，固体和滞留。 Solid (Figure 1) offers slightly lower resi
3、stance.固体（图1 ）提供略低于阻力。 The key to solid conductors is better performance at high frequencies.关键坚实的指挥是有更好的表现在高频率。 Figure 1图1 Stranded (Figure 2) offers greater flexibility, that is limpness, and greater flex-life, or flexes until failure.滞留（图2 ）提供更大的灵活性，这是limpness ，和更大的“弹性人生” ，或弯曲，直到失败的。 Figure 2图2 M
4、ulticonductor 多导体 As the name implies, multiconductor cables consist of many conductors.作为顾名思义，多导体电缆构成许多指挥家。 (Figure 3.) They are common in control applications but are rarely used for signal applications, and therefore, we will not be focusing on them for this paper. （图3 ）他们是在共同控制等方面的应用，但很少用于信号应用，因
5、此，我们将不会着眼于他们本文件。 Twisted Pairs 扭曲的对 Twisted pairs (Figure 4) consist of two insulated wires twisted together.对扭曲（图4 ）连续两个绝缘电线扭在一起。 They are specifically intended for carrying signals and were invented in the 1880s for wiring up the early telephone systems.他们是专为进行信号和发明，在1880年的接线了早期的电话系统。 Twisted pair
6、s offer low noise pick-up and low noise emission from a cable because it is a balanced line and because a balanced line offers common-mode noise rejection.扭曲对提供低噪声上升和低噪音的排放量从有线电视，因为它是一个均衡的路线，因为一个平衡的路线，提供了“共同模式的噪音抑制” 。 What is a Balanced Line? 什么是一个均衡的界线呢？ A balanced line is a configuration where two
7、 wires are kept close together, usually by twisting them (Figure 5).一个平衡的路线，是一个配置2线保持着密切在一起，通常由他们扭（图5 ） 。 Conductors need to be the same length, the same size, with a constant distance between them.导体必须相同长度，相同的大小，与不断之间的距离。 Figure 5图5 It should be noted that the signal, at any instant in time, is exa
8、ctly the same but opposite polarity on the two wires.应该指出的是，信号，在任何即时在时间，是完全一样的，但相反极性的就两个电线。 Another way of saying that is, if you note the signal voltage at any point of the cable, they should add up to zero.另一种方式的说是，如果你注意信号电压在任何一点的电缆，他们累加起来应为零。 When Noise Appears. 当噪音出现 。 Noise is a fact of life.噪音
9、是生活中的事实。 It is electromagnetic radiation and can come from many sources including fluorescent lighting, motors, car ignition systems, equipment such as hospital analyzers, transmission equipment from CBs, truck, taxis, radio and television broadcasters, and natural sources such as the sun.这是电磁辐射，并可以
10、来自许多来源，包括荧光照明，电机，汽车点火系统，设备，如医院，分析仪，传输设备，由立法会CB的，卡车，的士，电台和电视台，和自然来源，如太阳。 When noise appears, and hits the two wires in our twisted pairs (Figure 6), the electromagnetic radiation of the noise induces a voltage in both wires.当噪音出现，并击中两个电线在我们的扭曲对（图6 ） ，电磁辐射噪声诱导电压，在双方的电线。 However, the direction is the s
11、ame or common mode in both wires.不过，方向是相同的或“共同模式”在双方的电线。 Figure 6图6 When the two noise signals reach either end of the cable, there is either a passive balancing device (such as a transformer shown in Figure 6) or the equivalent active balanced input.当两个噪声信号到达两端的电缆，有一种被动的平衡装置（如变压器显示，在图6 ）或等值的积极平衡的投入
12、。 As you can see, the two noise signals on the two wires cancel each other out.你可以看到，两个噪声信号对两个电线取消对方。 In this way, the noise cancels out and the signal (which is differential mode) can continue through.这样一来，取消了噪音和信号（这是“差模” ）可以继续通过。 Coaxial Cable 同轴电缆 Coaxial cable, or coax, for short, is the other m
13、ost popular cable configuration.同轴电缆，或同轴电缆，总之，是其它最受欢迎的电缆配置。 The signal on the cable is not the same on the two conductors since the shield carries both ground and signal.该信号对有线电视是不一样的就两个导体以来，盾构进行地面和信号。 The two conductors are not the same size, same resistance.两个导体并不相同大小，相同的阻力。 Therefore, coax is not
14、 a balanced line.因此，同轴电缆是不是一个平衡的路线。 It is an unbalanced line.这是一个不平衡的路线。 Coax does not have the inherent noise rejection of twisted pairs.同轴电缆不具备固有的噪声抑制扭曲对。 But performance of coaxial cable can be far superior to twisted pairs.但性能的同轴电缆，可远优于扭曲对。 First, coax has extremely stable performance.首先，同轴电缆具有非
15、常稳定的性能。 The various parts of the cable are locked together.各部分电缆的“锁起来” 。 (Figure 7) This, as we will discuss later, gives much better performance especially at high frequencies. （图7 ）这方面，正如我们将讨论后，给出了好得多的表现，尤其是在高频率。 Figure 7图7 Shields 盾牌 Shields are added to twisted pairs, or multiconductor cables, t
16、o help prevent in ingress (interference) or egress (radiation) of noise.盾牌加上扭曲的对，还是多导体电缆，以帮助防止在侵入（干涉）或出口（辐射）的噪音。 Shields are an inherent part of coax cable.盾牌是固有的一部分同轴电缆。 There are six basic shield configurations:有六个基本盾牌配置： Unshielded屏蔽 o Twisted pairs, especially in data, are often unshielded.对扭曲，特
17、别是在数据，往往是屏蔽。 Coax, by definition, cannot be unshielded.同轴，根据定义，不能屏蔽。 Serve/spiral shields服务/螺旋盾牌 o Serve or spiral shields are simply wound around the inner conductors.服务或螺旋盾牌，只是伤口周围内导体。 Braid shields编织盾牌 o Conductors woven or braided around a core.导线编织或编织周围的一个核心。 Most effective from 1,000 Hz to 50
18、MHz.最有效的，从1000赫兹至50兆赫。 French braid shields法国编织盾牌 o This is a combination of serve and braid.这是一个相结合的服务和编织。 Here two serves are braided along one axis.这里的两个服务是辫状沿一轴。 Foil shields铝箔盾牌 o These are the simplest, cheapest, and easiest to apply.这些都是最简单，最便宜，最简便的申请。 They are most effective above 50 MHz他们是最
19、有效的上述50兆赫 Combination shields组合盾牌 o Combined foil and braid shields are effective at low and high frequencies.联合金属箔和编织的盾牌是有效的在低和高频率。 Unshielded 屏蔽 Unshielded cable is appropriate where no noise is present, such as no crosstalk from adjacent wires.屏蔽电缆是适当的情况下，没有噪音，是目前，如无串扰来自邻近的电线。 Or it can be used i
20、f you dont care if there is noise, that noise cannot substantially affect the signal on the cable.或它可以用来如果你不照顾，如果有噪音，噪音无法大幅影响信号的电缆。 Unshielded cables are especially prevalent in the data world where pairs have very tight twists, or may use conductors that are bonded together.屏蔽电缆，特别是普遍存在的数据，世界上对已十分紧
21、张，曲折，或者可能使用的导体是保税在一起。 Such high-performance pairs are good to excellent at not picking up or radiating noise.等高性能运算对是优良的不回升或辐射噪声。 Serve/Spiral Shields 服务/螺旋盾牌 Serve or spiral shields can be made to be ultra-flexible.服务或螺旋盾牌，可以向被超灵活。 However, serve shields can open up when flexed, which compromises s
22、hield effectiveness.不过，服务的盾牌，可以开辟时，弯曲，妥协盾牌的成效。 A spiral of wire obviously affects the inductance of the shield.螺旋线，显然影响到电感的盾牌。 Therefore spiral shields are rare in video and are usually audio only.因此，螺旋盾牌，是罕见的视频和音频通常只。 There is a double spiral serve, also known as a Reussen shield.有一个双螺旋服务，也称为“罗伊森”挡
23、箭牌。 This configurations shorts out the inductive effect of a signal spiral, but the shield can still open up when flexed.这配置“短裤”诱导效应的一个信号螺旋，但盾牌仍然可以开放时，弯曲。 This double serve is common on many European and Japanese audio snakes.这种双重服务，是共同对许多欧洲和日本的音频蛇。 The ultra-flexibility of the cables is a key.超灵活的电
24、缆是一个关键。 However, it should be realized that users of this cable type often trade flexibility for performance.但是，应当看到，用户电缆，这类型常常贸易的灵活性的表现。 Braid Shields 编织盾牌 Braid shields are formed by spinning wires or groups of wires around a core.编织的盾牌形成纺纱的电线或团体的电线周围的一个核心。 This slow and labor-intensive process ma
25、kes braiding the most expensive single step of cable manufacturing.这缓慢和劳动密集的过程，使编织最昂贵的单步电缆制造。 Single braid coverage of up to 95% can be realized.单编织的覆盖面达95 是可以实现的。 Double braid coverage can be up to 98% coverage.双辫的覆盖范围可达到98 的范围。 Since braids always have holes where the wires cross, 100% coverage no
26、t possible with braid.由于编织始终有“漏洞”的地方电线交叉， 100 的范围不可能与编织。 Braid shields are most effective at frequencies from 1,000 Hz to 50 MHz.编织的盾牌是最有效的频率从1000 Hz至50兆赫。 For these frequencies, the low resistance of a braid gives good coverage.这些频率，低电阻一个辫子，让良好的覆盖面。 Below 1,000 Hz there is no standard braid materia
27、l which is effective.下面千赫兹有没有标准的编织材料，是有效的。 The wavelengths are so long, and the low frequency energy so pronounced, that the only effective shielding is solid steel conduit.波长是这么久，和低频率能量，使突出的，唯一有效的屏蔽是牢固的钢导管。 And, at 60 Hz, even steel conduit gives 27 dB of noise reduction. ，并于60赫兹，甚至钢导管给予二十七分贝降噪。 At
28、 frequencies above 50 MHz, braid becomes wavelength dependant where the holes look larger and larger as the wavelength gets smaller and smaller.在频率超过50 MHz的辫子变成“波长受养人”而孔看大作为波长得到小。 The effective coverage of a braid gets worse and worse, especially compared to a foil shield, which has no holes.有效的覆盖面一
29、辫得到日益严重，尤其是相比，一箔盾牌，这是没有漏洞。 French Braid Shields 法国编织盾牌 French braid shields are a combination of serve and braid.法国编织盾牌，是一个相结合的服务和编织。 A French braid consists of two serves braided along one axis.一位法国辫子连续两个服务编织沿一轴。 This gives cables excellent flexibility, rivaling those Reussen shield in European and
30、 Japanese cables.这使电缆优良的弹性，足以媲美那些罗伊森盾构在欧洲和日本的电缆。 And yet, unlike Reussen shields, lab tests indicate that French braids have excellent RF performance.然而，不像罗伊森盾牌，实验室测试表明，法国编织卓越的射频性能。 This may be partly because the braiding shorts out the inductive effect of serve shields and shorts out the RF noise t
31、oo.这可能是部分原因是编织“短裤”诱导效应服务盾牌和“短裤”射频噪音太大。 Because it takes the same number of steps as a regular braid, French braids are the same cost as regular braid.因为它同样数目的步骤，作为一个经常性编织，法语编织是相同的费用作为经常编织。 Maximum coverage of a French braid is 98%.最高的覆盖面，法国辫子是98 。 Foil Shields 铝箔盾牌 Foil shields are the easiest and c
32、heapest to apply.铝箔盾牌，是最容易和最廉价的申请。 They can be applied as fast as the cable will run.他们可应用于一样快电缆将运行。 Foil shields actually consist of two layers, a metal layer and a plastic substrate of polyester.铝箔盾牌，实际上包括两个层次，一个金属层和塑料基板的聚酯。 This can be easily seen since the foil is silver on one side and colored
33、(red, blue green or other colors) on the plastic side.这可以很容易地以来所未见的铝箔是银，另一面色（红，蓝绿色或其它颜色）对塑料的一面。 Since foil shields lack the mass and low resistance of a braid shields, the exhibit poor to average low-frequency performance.由于铝箔盾牌，缺乏大规模和低阻力的一个编织的盾牌，展览穷人平均低频表现。 However, after 50 MHz, foil shields have
34、excellent high frequency coverage.不过，经过50兆赫，箔盾牌，有优良的高频率的覆盖面。 Since foil is a continuous sheet of metal, coverage can be 100%.由于铝箔是一个持续不断的资产负债表的金属，覆盖范围可100 。 Combination Shields 组合盾牌 Combination shields consist of foil and braid combined.组合盾牌构成箔和编织的总和。 Occasionally there can be more than one layer of
35、 each, such as quad cable television cable, so called because it has two layers of foil and two layers of braid.偶尔可以有一个以上的层的每个，如“四方”的有线电视电缆，所谓，因为它有两个层次的铝箔和两层编织。 Because of this, combination shields are the most expensive of all.正因为如此，组合盾牌，是最昂贵的一切。 But they also give the best broadband coverage, sinc
36、e it contains a braid for low frequencies and a foil for high frequencies但他们也提供最佳的宽频网络已覆盖，因为它包含了编织为低频率和铝箔的高频率 The difference between broadcast coax cables, which often contain foil and braid in digital applications, and CATV/broadband cable is that CATV cables use low coverage braid (sometimes as lo
37、w as 40).之间的差额广播同轴电缆，其中往往含有金属箔和编织在数码应用，以及有线电视/宽带电缆是有线电视电缆的使用普及率低的辫子（有时低至40 ） 。 The reason is that these cables only operate above 50 MHz.原因是这些电缆不仅经营高于50兆赫。 At those frequencies, braid shields are ineffective.在这些频率，编织盾牌，是无效的。 It is actually the foil shield that is doing all the noise reduction.它实际上是铝
38、箔屏蔽，就是尽一切的消减噪音。 The braid shield is there to give the F-connector something to grab onto.该编织盾牌是有给的F -连接器的东西攫取上。 Itsa reliability issue, not a performance issue.它的可靠性问题，而不是性能问题。 CATV braids are aluminum belying their low cost and indicating that this braid is not included for performance.有线电视编织是铝bely
39、ing其成本低，并表示这辫子是不包括的表现。 Combination braids are required for digital video such as SDI or HD.结合编织所需的数字视频等的SDI或HD 。 The Broad frequency range of SDI (135 MHz) or HD (750 MHz) make a combination shield a requirement.广泛的频率范围的SDI （ 135 MHz ）或高清（ 750兆赫）作出的组合盾的要求。 That being said, it should be notes that do
40、uble-braid cables (such as Belden 8281) can still operate at these high frequencies.说了这番话之后，应该注意到，双编织电缆（如在Belden 8281 ）仍然可以运作，在这些高频率。 It is simply that the effective distance they can run is severely reduced compared to cables with foil + braid (among other improvements).这只不过是认为，有效的距离，他们可以运行，是严重减少相比
41、，电缆与铝箔+编织（除其它改善） 。 Most precision digital cables contain 95% braid + 100% foil最高精度数字电缆载有95 的编织+ 100 箔 Cable Parameters 电缆参数 Cables are made up of metals and plastic.电缆弥补了金属和塑料。 The choice of metals and the choice of plastic can have a significant effect on the performance of that cable.选择金属和塑料的选择可以有
42、重大影响的表现，有线电视。 Effects such as capacitance, impedance, inductance and skin effect are derived from the choice of materials.的效果，如电容，阻抗，电感和趋肤效应是来自材料的选择。 The Conductor 导体 When comparing metals, each can be characterized by resistance as the next table shows.当比较金属，每一个可以抵抗的特点，作为未来表显示。 Silver, while the be
43、st conductor, is expensive and difficult to work with.银，而最好的导体，是昂贵和困难的工作。 Copper is the most common metal.铜是最常见的金属。 Metals 金属 Resistance 阻力 Circular mil-ohms per foot at 20C 通告的mIL -欧姆每脚在20 Silver银 9.9 Copper铜 10.4 4月10日 Gold黄金 14.7 7月14日 Aluminum铝 17十七 Nickel镍 47 47条 Steel钢铁 74七四 One advantage of c
44、opper is its ability to be annealed. 1铜的优势，是它能够以“退火” 。 After being drawn through dies from large rod to small wire, copper will get brittle.之后，正在草拟中，通过模具从大至小棒线材，铜将得到脆性。 By placing it in an oven at around 700 o F, the copper will become flexible again.通过将它放在烤箱约700 度 ，铜将成为灵活的一次。 Gold is most commonly
45、used on connectors because it will not oxidize.黄金是最常用的对连接器，因为它不会氧化。 Aluminum is often used in low-cost cable constructions such as CATV/broadband shields, or in low-cost consumer audio interconnect cables.铝是常用在低成本的电缆建设，如有线电视/宽频盾牌，或在低成本的消费类音频和互连电缆。 Wire Gage 线测厚仪 The size of each wire is describes as
46、 the gage size, and is measured in units of American Wire Gage (AWG).的大小，每个线是描述作为计大小，是衡量单位在美洲线测厚仪（ AWG的） 。 Below is a list of gages with a description of how small or large that size is:下面是一个清单计与说明如何是小型企业还是大型规模是： 40 AWG 40 AWG的 smaller than a hair小于头发 30 AWG 30 AWG的 sewing thread缝纫线 20 AWG 20 AWG的 d
47、iameter of a pin直径一针 10 AWG 10 AWG的 knitting needle针织针 1 AWG 1阵列波导光栅 pencil铅笔 1/0 1 / 0 1-aught finger “ 1 - aught ”手指 Resistance 阻力 The choice of metal, the gage size of the wire, and the length of the wire can determine the resistance of any conductor.选择金属，计大小的铁丝网，和长度的导线可以判断的抵抗任何导体。 Charts are ava
48、ilable, such as in the back pages of the Belden Master Catalog, which shows the resistance for stranded wire from 36 AWG to 10 AWG, and the resistance for solid 40 AWG to 10 AWG.图表可用，如在回到页的在Belden主目录，这表明阻力钢绞线由36 AWG的10 AWG的，和抵抗固体40 AWG的10 AWG的。 All wire has resistance.所有电线已阻力。 Resistance affects the signal by turning part of the signal into heat.阻力影响信号的转折部分的信号进入热。 This creates a voltage drop on the wire when one end is compared to the other.这将创建一个压降对导线时，一年底相比，是其它。 The voltage drop can be determined by one of the formulas of Ohms Law, E =I 2 R, where E is the voltage drop on the wire, I is the
