MXPA00010430A - Lightning retardant cable - Google Patents

Abstract

There is provided a cable which retards lightning. The cable includes at least one internal conductor which may be a power conductor or a signal conductor. A choke conductor is wound about the internal conductor in the shape of a spiral. If lightning strikes near the cable or a device which is attached to the cable, such as an antenna, the choke conductor presents a high impedance to the current caused by lightning and will prevent the lightining current from flowing down the choke conductor, thus entering the internal conductor, thereby preventing damage to the internal conductor and any associated electronic equipment. Preferably, a shield is also spiraled wound about the internal conductor adjacent to the choke conductor in a direction opposite to the choke conductor, whereby the angle formed by the crossing of the choke conductor and the shield is approximately 90°to block the magnetic field component of the lightning discharge.

Description

RAY REMOTE CABLE BACKGROUND OF THE INVENTION This invention relates to electric cable. More particularly, 5 refers to an electrical cable that retards the rays so that the cable is not substantially affected by the beam and, in the case of a communication cable, the communication signal in the signaling conductor inside the cable is not affected. substantially, as well as its associated equipment. Although this invention is applicable to both power and communication cable, most of the discussion discussed herein will focus on the communication cable used in conjunction with an antenna. As used herein, the term "antenna" includes television and radio antenna, satellite dishes and other devices that receive electromagnetic signals. A major problem associated with an antenna is caused by lightning strikes on the antenna. Often the high current associated with the lightning will travel through the communication cable. The cuat is connected between the antenna and the electronic equipment. 20 This current will damage the electronic equipment. According to The Lightning Book. by Peter E. Viemeister, autoinduction in a driver can happen during a lightning strike. This occurs because lightning currents can rise to a rate of approximately 15,000 amps in one millionth of a second. 25 For a straight conductor with the usual cross section, this current -.: -jaJ &ájAasfii fiS »» -. . -,. .- yy¡ ".-- -« y ^. that arises can produce almost 19,670 volts per meter of wire, which is enough to jump an insulated space to a nearby conductor, such as the center conductor, on a coaxial cable. Currently, the cable protection against lightning is more focused on the installation of the cable within a system. The National Electric Code attempts to ensure an appropriate path for lightning discharge, thereby reducing damage to equipment connected to the end of the cable. The cable in and of itself offers little or no protection from the electric fields or associated magnetic fields ^ lO with the lightning strike. Even though electrical codes provide suggestions for the installation and landing of equipment, their main focus is to provide a straight path to land rays to discharge and eliminate potential differences between the two items. 15 Figure 1 is an example of a domestic television antenna installation according to the National Electric Code. If a lightning bolt were to fall on antenna 10, half the charge would be on the wire • of ground 12 of which is attached to the mast 14 of the antenna, and the other half would be on the outer cover 16 of the coaxial cable which is connected to the terminals 18 of the antenna. Theoretically, the current in the coaxial cable 16 would travel to the antenna discharge unit 20 and then through the conductor 22 to ground. The central conductor or signal conductor of the coaxial cable, however, is unprotected, which means that the damage to the electronics in the receiver is likely to occur. other components within the home. Also, the larger the input wire, the greater the problem. As the beam falls on this antenna 10 and discharges to ground, a large magnetic field is created along the coaxial input wire 16 and ground wire 12. In • right angles to this electric field there is an exceptionally strong magnetic field 5 surrounding the entire cable. In addition, the beam follows the straight path, closer and better to ground. Any sharp bends, twists or turns of the ground wire creates resistance for quick discharge. See page 201 of The Lightninq Book. with reference to the above. This resistance usually causes the jump discharge of the ground wire with the tilt and makes a path of least resistance.

OBJECTIVES OF THE INVENTION It is an object of this invention to provide an improved ray-retardant cable. It is another objective to provide a lightning retardant cable that handles both electric and magnetic fields caused by lightning.

BRIEF DESCRIPTION OF THE INVENTION In accordance with one form of this invention, a lightning delay cable is provided that includes at least one internal conductor. The internal conductor can be a signal conductor or a power conductor. A signal driver carries a signal containing information. An energy conductor conducts current to operate devices and equipment.

^^^^^^ Ai ^^^^ A shock driver is provided. The shock conductor is wound around the inner conductor in the form of a ? ^ spiral. The shock driver is not in contact with the internal driver. The shock conductor has a very high impedance to the electrical current caused by lightning when the lightning strikes near the cable. Preferably, the inner conductor is made of metal to conduct electrical signals or current, even though the internal conductor may be an optical fiber. ^ 10 It is also preferred that a spiral cover is placed below the shock conductor. The spiral cover is also wound around the inner conductor, but in a direction opposite to the shock conductor. The adjacent windings of the cover are not in electrical contact with each other and act as another shock. Preferably, angles of 90 ° are formed at the crossing points between the shock conductor and the cover. The shock driver dissipates the electric field caused by the ^ lightning strike. The cover performs two functions. It acts as a shock in the opposite direction of the shock driver and thus increases the cancellation process and acts as a Faraday screen to greatly reduce the associated magnetic field. It is also preferred that one side of the cover is insulated so that when the cover is wound around the cable a winding is not in electrical contact with the pre-winding or the next. This forms a shock cover. The shock driver can also be isolated. In addition, one end of the insulated shock conductor may be electrically connected to one end of the cover. It is also preferred that a global outer sheath 5 be provided for the cable and that a ground conductor be attached to the outer sheath.

BRIEF DESCRIPTION OF THE DRAWINGS The subject matter that is seen as the invention is set forth in the appended claims. The invention itself, however, together with additional objectives and advantages thereof can be better understood with reference to the accompanying drawings in which: Figure 1 is a simplified electrical diagram showing a signal transmission system of antenna and ground of the prior art; Figure 2 is a simplified electrical diagram showing the antenna and ground signal transmission system of the subject invention; Figure 3 is also a simplified electrical diagram showing the antenna and ground signal transmission system of the subject invention; Figure 4 is a side elevational view of the ray retarder cable of the subject invention; Figure 5 is a side elevational view of an alternative embodiment of the ray-retardant cable of the subject invention; Figure 6 is a side elevation view of another alternative embodiment of the lightning retarder cable of the subject invention; Figure 7 is a side elevational view of another ^ k modality, alternative to the ray-retardant cable of the subject invention; Figure 8 is a cross-sectional view of the spiral protection cover of Figures 5, 6 and 7; Figure 9 is a side elevation view of another alternative embodiment of the lightning retarder cable of the subject invention for an energy application; Figure 10 shows a cross-section of the conductor of P10 isolated shock that can be used with another embodiment of the invention; Figure 11 shows an inductive meter that measures the inductance of a straight wire; Figure 12 shows a pair of inductors wound in an opposite manner; Figure 12A shows the inductors of Figure 12 that are closely spaced and connected together at their opposite ends; iP Figure 12B shows the inductors of Figure 12A having an inductive meter connected thereto; Figure 13 shows the cable using the construction of the shock conductor of Figure 10, wherein only one end of the shock conductor is connected to one end of the protection cover; Figure 14 is a more detailed view of the cable of the Figure. DESCRIPTION OF PREFERRED MODALITIES Referring now more particularly to Figure 3 which refers to an embodiment of the invention where the lightning delay cable is a communication cable, provides a system 24 for transmitting antenna signal and landing for landing antenna 10. As previously indicated, antenna 10 may also be a satellite dish or other device for receiving signals from the air. The system 24 includes the lightning retardant cable 26, which is the cable of the subject invention and will be described in more detail more ^ lO forward. The lightning delay cable 26 is connected to the antenna 1 0 in the cable connection box 28. The cable 26 is also connected to a standard antenna discharge unit 30. A typical antenna discharge unit 30 is a commercially available Tru Spec from C Z Labs. A coaxial cable 32 is connected to the unit 30 of download and electronic equipment (not shown). A ground wire 34 connects the antenna discharge unit 30 to ground clamps 36 and 38. The ground clamp 38 F is, in turn, connected to the ground rod 39. Furthermore, the antenna mast 40 is connected to the ground clamp 38 through the ground wire 42. Figure 2 is similar to Figure 3, but illustrates some of the details of the cable 26. In the communication cable embodiment of this invention, the cable 26 is preferably a coaxial cable, though, the cable 26 could be a fiber optic cable or conductor cable twins. A communication cable must include at least one ^^^^^^^^ ^ ^^^^^^ ^^^^^ signal driver. In the preferred embodiment of the communication cable of this invention, however, the cable 26 is a coaxial cable. Figure 2 illustrates the center conductor 44. Driver • central 44 is a signal conductor and is connected to the 5-terminal box 46 attached to the mast of the antenna 10. The signal conductor 44 is connected through the antenna discharge unit 30 to the coaxial cable 32. The spiral shock conductor 56 surrounds the signal conductor 44 and is connected to the antenna discharge unit 30 which, in turn, is connected to the ground conductor 34. The cable 26 will be discussed in more detail below. Figure 4 shows the lightning retardant cable 26 having a central signal conductor 44 which is surrounded by dielectric foam 50. A protective cover 52 of coaxial cable surrounds the dielectric 50. The insulated sheath 54 surrounds the protective cover 52.

A shock conductor 56 is wound around the outer sheath 54 in a spiral mode. A global outer insulated sheath can be placed over the cable to provide protection for the cable. He • Shock conductor 56 should be large enough to handle high currents caused by lightning without melting. The driver of The shock 56 must be at least 17 gauge and preferably 10 gauge. Preferably the shock conductor is made of copper. If the shock conductor is made of a bundle of round copper wires, the beam must be equivalent to at least 17 gauge wire or larger. Referring now to Figure 2, if the beam hits the antenna 10, the energy of that beam would be divided normally, that is, one half would follow the ground wire 42 and the other half follow the wire 26 to the ^^ ground rod 39. However, since the cable 26 forms an electric shock due to the spiral conductor 56, that is to say, the conductor 56 actually crashes the current flow due to its high impedance to the lightning current which has a very rapid rise time, the majority of emergence follows the ground wire 42 to ground and does not follow the ground wire 26 . One half of the lightning energy that would fall through the wire 26 after a beam struck would be ^ 10 canceled quickly by the shock action. Each time the shock conductor 56 is rotated around the cable, it causes the electric field generated by the beam to interact with itself, thus blocking the flow of current. As with any electric shock, there is an electric field, as well as a magnetic field in some straight to the electric field. The lightning causes a tremendously large magnetic field due to the huge discharge of electrical current. Figure 5 shows a ^ alternative modality of the ray-retardant cable of the subject invention which includes a special protection cover for blocking the magnetic component of lightning discharge, thus acting as a Faraday screen. In Figure 5 there is provided a central signal conductor 44, dielectric 50, protective cover 52 for standard coaxial cable and sheath 54 for coaxial cable. A protective cover 58 rolled in The substantially flat spiral is wound onto the upper part of the sheath 54 of coaxial cable. As shown by a cross section of the spiral protective cover 58 in Figure 8, the cover includes a portion • 60 upper conductive metal which is insulated by 5 plastic insulation 62 in the bottom. This way, the cover can be in spiral form on itself without causing an electrical short. The metal portion 60 of the cover 58 is preferably made of aluminum or copper. The cover 58 is commercially available. The shock conductor 56 is coiled on top of the cover 58 in the opposite direction to the spiral of the cover 58. Preferably, both the cover 58 and the shock conductor 56 are in spirals at 45 ° angles with respect to the signal conductor 44. Thus the cover and The crash driver will intersect at 90 ° angles. Alternatively, the spirals for both the shock driver and the The cover could be adjusted to various angles to maximize the inductance depending on the desired effect. In the embodiment of Figure 5, the shock conductor 56 is in electrical contact with the metal portion 60 of the cover 58. However, in the embodiment of Figure 6, a sheath 64 is provided. insulated between the spiral cover 58 and the shock conductor 56 and a small wire 61 for drainage is placed in contact with the cover 58 between the cover 58 and the cover 64. The drain wire 61 allows one to conveniently terminate the cover. In the design shown in Figures 5 to 8, both electric and magnetic fields are indicated. The electric field is located by the spiral shock conductor 56 which, as indicated above, functions as an electrical shock. The magnetic field is located by the spiral cover 58, which acts as a Faraday screen.

• Also, the spiral cover acts as a flat shock in the opposite direction of the spiral electric shock 56, thus increasing the cancellation effect. Therefore, the cover 58 has two functions. As indicated above, preferably, the cover 58 is preferably at an angle of 45 ° with respect to the conductor 44 of central transmission signal and is spirally wrapped in the counterclockwise direction. The shock conductor 56 is also preferably at an angle of 45 ° with respect to the center conductor 44, but is spiraling in the opposite direction around the cover 58, ie, in the clockwise direction. The directions in which the shock driver and signal conductor are coiled could be reversed. The result is a 90 ° angle between the magnetic cover and the electric shock. • Referring now more particularly to Figure 7, for ease of installation, a ground wire 66 can be made as a cable component 26. The ground wire 66 is attached to the external sheath 65 of the cable and is embedded in plastic that forms part of the sheath 65 extruded. The ground wire 66 travels the length of the cable. The ground wire is set apart from the main cable so that it can be easily detached and attached to a ground rod. 25 The cable shown in Figure 5 has been tested in the laboratory . ~ and in the field. The results show a substantial improvement over the prior art. The detailed description above mainly discusses applications of communication cables of the invention. Figure 9 shows a lightning retardant cable 69 of the subject invention for energy applications. The internal conductors 70 and 72 are energy conduits which are normally of heavier gauge than the communication conduits. Often a gravel driver (not shown) is placed adjacent to the ^ 10 power conductors. The conductors 70 and 72 are covered by the insulated cover 74. The shock conductor 56 is coiled around the cover 74 in the same manner as shown and described with reference to Figure 4. In addition, the arrangement of the protective cover shown in Figures 5, 6 and 7 can be used. also in power cable applications. The shock conductor 56 may be insulated with insulation so that it is not in electrical contact with the protective cover ^ 58. This insulation will electrically isolate the shock conductor 56 from the protective cover 58 so that one can separate the electric and magnetic fields. This will allow one to adjust the two windings, that is, the protective cover and the shock, separately for maximum inductance. Figure 10 shows a cross-sectional view of an isolated shock conductor. Article 56 is the shock conductor and article 76 is an insulating cover. It may be necessary, depending on the application, that the insulating sheath 76 of the shock conductor has been slightly conductive. A compound, such as carbon, can be added to the insulation to increase this conductivity, that is, to make the semiconductor insulation. 5 The beam will usually follow the path of the least resistance or least inductance to ground. Each straight wire has an inductance. To minimize the inductance, you can actually use two coils wound opposite each other. The fields of these two coils will be canceled between them and will result in "0" induction. In f a Figure 1 1, Article 78 illustrates an induction meter that measures the inductance of a straight wire 77. In Figure 12, Articles 79 and 80 illustrate inductors. If the second inductor 80 is wound opposite the inductor 79, as shown at 81 in Figure 12A, and the two are electrically connected at both ends 82, then the The inductance should be read "0", as illustrated by the meter 78 in Figure 12B. Certain applications of lightning delay wire can be * increased if only one end of the wire has the shock 56 connected or grounded to the protective cover 58. This allows the protective cover function as a Faraday screen that protects the coax or internal wires from the magnetic fields of any induced energy. Figure 13 illustrates this construction. In this illustration, the shock 56 and the protective cover 58 are in electrical contact at one end of the cable only. This can be achieved wound the shock 56 around the protective cover 58 so which are in mechanical and electrical contact, as illustrated in Figure 14. Figure 14 shows a cross-sectional view of the cable 65. The • Article 58 is the protection cover wound in a spiral way that there is 100% full overlapping cover. The shock 56 is detached from the insulation and wound around the protective cover 58 so that it is in mechanical and electrical contact. From the foregoing description of the preferred embodiments of the invention, it will be apparent that many modifications in it. It will be understood, however, that the embodiments of the invention are examples of the invention only and that the invention is not limited thereto. It should be understood therefore that it is intended in the appended claims to cover all modifications that fall within the true spirit and scope of the invention. •

Claims (24)

1. CLAIMS 1. A lightning delay cable comprising: ^ at least one internal conductor; a shock driver; said rolled shock driver 5 around said inner conductor in the form of a spiral; said shock conductor that is not in direct contact with said internal conductor; said shock conductor having a high impedance to the electric current caused by the beam when the beam falls near said wire; a spiral protection cover; said spiral protection cover which is wound around said inner conductor in a direction which is opposite to the direction in which said shock conductor is wound; said shock conductor and said spiral protective cover each having first and second ends; Said first end of said shock conductor connected to said first end of said spiral protective cover, and said second end of said shock conductor connected to said second end P of said spiral protective cover; magnetic fields that are formed by said shock conductor 20 and said spiral protective cover when current flows through said shock conductor and said spiral protective cover due to a lightning falling near said cable; said magnetic fields that are substantially canceled, whereby the damaging effects of the lightning strike are reduced.
2. 2. A cable as set forth in claim 1, wherein said internal conductor is made of a material that conducts electric current.
3. 3. A cable as set forth in claim 1, wherein said internal conductor is a signal conductor.
4. 4. A cable as set forth in claim 2, wherein said internal conductor is an energy conductor.
5. 5. A cable as set forth in claim 3, wherein said signal conductor is at least an optical fiber for driving light.
6. 6. A cable as set forth in claim 2, further including an electrical insulation layer placed between said internal conductor and said shock conductor.
7. 7. A cable as set forth in claim 1, wherein said shock conductor has a diameter of at least caliber. 17. 17.
8. A cable as set forth in claim 7, wherein said internal conductor is a signal conductor; a protective cover of coaxial cable surrounding said signal conductor, whereby said cable is a coaxial cable.
9. 9. A cable as set forth in claim 1, wherein said impact conductor is coiled at an angle of approximately 45 ° with respect to said internal conductor.
10. A cable as set forth in claim 1, wherein said spiral protective cover is in the form of a conductor 25 plane; at least one step of said flat conductor having electrical insulation joined to it.
11. 1 1. A cable as set forth in claim 10, which includes In addition, an insulation layer placed between said shock conductor and said spiral protective cover.
12. 12. A cable as set forth in claim 1, further including an insulation layer surrounding said shock conductor.
13. A cable as set forth in claim 12, wherein said insulation layer surrounding said shock conductor includes an amount of conductive material, whereby said layer of I 10 insulation is semiconductor.
14. 14. A cable as set forth in claim 12, wherein said spiral protective cover and said shock conductor intersect at an angle of approximately 90 °.
15. 15. A cable as set forth in claim 13, further including an outer cover of said cable.
16. 16. A cable as set forth in claim 1, further including a ground conductor. ^ P
17. 17. A cable as set forth in claim 15, further including a ground conductor; said ground conductor joined to the said outer sleeve.
18. 18. A cable as set forth in claim 13, wherein the spiral angles of said shock conductor and said protective cover can be adjusted to maximize the inductance.
19. 19. An antenna and landing signal transmission system comprising: a lightning delay cable; said cable including at least one signal conductor; said signal driver for driving j ^ a signal containing information; a shock driver; said rolled shock conductor 5 around said signal conductor in the form of a spiral; said shock conductor having a high impedance to the electric current caused by lightning when the beam falls near said wire; a spiral protective cover; said spiral protective cover being wound around said signal conductor in a ^ p10 the opposite direction to the direction in which said choke conductor is coiled; said spiral protective cover without direct contact with said signal conductor; said shock conductor and said spiral protective cover each having first and second ends; said first end of said connected shock conductor 15 to said first end of said spiral protective cover, and said second end of said shock conductor connected to said second end of said spiral protective cover; magnetic fields that are formed by said shock conductor and said spiral protective cover when current flows through 20 said shock conductor and said spiral protective cover due to a lightning falling near said cable; said magnetic fields being substantially canceled, so that the effects of lightning damage are reduced.
20. 20. A system as set forth in claim 19, wherein said signal conductor is made of a metallic material that conducts electric current; an electrical insulation layer placed between said signal conductor and said shock conductor.
21. 21. A system as set forth in claim 19, further including an insulation layer surrounding said conductor of 5 shock.
22. 22. A system as set forth in claim 21, wherein said insulation layer surrounding said shock conductor includes an amount of conductive material, whereby said insulation layer is semiconductive. ^ 10
23. 23. A system as set forth in claim 19, wherein said spiral protective cover and said impact conductor intersect at an angle of approximately 90 °.
24. 24. An antenna and landing signal transmission system comprising: a lightning delay wire; said cable including at least one signal conductor; said signal driver for driving a signal containing information; ^ P a shock driver; said shock conductor wound around said signal conductor in the form of a spiral; said shock conductor having a high impedance to the electric current caused by lightning when the lightning strikes near said wire; a spiral protective cover adjacent to said shock conductor; said spiral protective cover being wound around said signal conductor; said spiral protective cover and said 25 shock conductor being rolled in opposite directions; each end of said shock conductor connected to an adjacent end of said spiral protective cover; a global external cover that covers said cable; a ground conductor; said ground conductor attached to said global outer sheath. 5 • • 4áfe ^ c ^ »^^ ¡» -