【电力行业】电线电缆技术文件
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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.绝缘中心导体和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.指挥家来了俩个变化，固体和滞留。 Solid (Figure 1) offers slightly lower resistance.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当下高频率。
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 my beloved girl是什么意思，和更大的“弹性人生” ，或弯曲，直到失败的。
Figure 2图2
Multiconductor 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 ud 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，因此，我们将不会着眼于他们本文件。
Twisted Pairs 如何美白脸扭曲的对
Twisted pairs (Figure 4) consist of two insulated wires twisted together.对扭曲（图4 ）连续俩个绝缘电线扭在一起。 They are specifically intended for carrying signals and were invented in the 1880’s 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。cross是什么意思 hayley salesTwisted pairs offer low noi pick-up and low noi emission from a cable becau it is a balanced line and becau a balanced line offers "common-mode noi 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 wires are kept clo 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 ）如何拍马屁 。 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，和不断之间的距离。
Figure 5图5
It should be noted that the signal, at any instant in time, is exactly 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，但相反极性的就俩个电线。 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 Noi Appears…. 当噪音出现… … 。
Noi is a fact of life.噪音是生活中的事实。 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 CB’s, truck, taxis, radio and television broadcasters, and natural sources such as the sun.这是电磁辐射，且能够来自许多来源，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。 management是什么意思
When noi appears, and hits the two wires in our twisted pairs (Figure 6), the electromagnetic radiation of the noi induces a voltage in both wires.当噪音出现，且击中俩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 same 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。 爱由田
Figure 6图6
When the two noi 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.当俩个噪声信号到达俩端的电缆，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。 As you can e, the two noi signals on the two wires cancel each other out.你能够见到，俩个噪声信号对俩个电线取消对方。 In this way, the noi 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” ）能够继续通过。
Coaxial Cable 同轴电缆
Coaxial cable, or coax, for short, is the other most 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俩个导体以来，盾构进行地面和信号。 The two conductors are not the same size, same resistance.俩个导体且不相同大小，相同的阻力。 Therefore, coax is not 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 noi 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
轴电缆具有非常稳定的性能。 The various parts of the cable are "locked together".各部分电缆的“锁起来” 。高中英语说课稿 (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, to help prevent in ingress (interference) or egress (radiation) of noi.盾牌加上扭曲的对，仍是多导体电缆，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。经历挫折
