ELECTRICALLY CONDUCTIVE CABLE AND METHOD
20200303092 ยท 2020-09-24
Inventors
Cpc classification
H01B11/12
ELECTRICITY
International classification
H01B7/30
ELECTRICITY
Abstract
A method for reducing frequency dependent energy loss and phase errors from end to end as a function of the frequency of audio-range signals conducted therein including obtaining an electrical wire having a first end and an opposing second end and comprising of an electrically conductive metal with a conductivity between 0 and about 3.2* 10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% International Annealed Copper Standard (IACS), wherein the electrically conductive metal includes a relative magnetic permeability between 0 and 2, and transmitting audio-range signals from the first end to the second end, wherein the frequency dependent energy loss and phase from the first end to the second end is a function of a frequency of the audio-range signals transmitted therein.
Claims
1. An improved, signal carrying, electrically conductive cable having reduced frequency dependent energy loss and phase errors from end to end as a function of the frequency of audio-range signals conducted therein comprising: a. one or more insulated, first electrical wires with two ends and comprising of a first electrically conductive metal with a conductivity between 0 and 3.2*10.sup.6 (ohm-meter).sup.1 or between 0% and 5.5% International Annealed Copper Standard (IACS); and b. one or more insulated, second electrical wires with two ends and comprising of a second electrically conductive metal, wherein the first electrically conductive metal includes a relative magnetic permeability between 0 and 2.
2. The improved electrically conductive cable in claim 1, wherein the second electrical wire is comprised of a second electrically conductive metal with a conductivity between 0 and 3.2*10.sup.6 (ohm-meter).sup.1 or 0% and 5.5% IACS.
3. The improved electrically conductive cable in claim 2, wherein the second electrically conductive metal includes a relative magnetic permeability between 0 and 2.
4. The improved electrically conductive cable in claim 1, wherein the second electrical wires are neutral or ground wires comprised of an electrically conductive metal with a conductivity equal to or greater than 3.2*10.sup.6 (ohm-meter).sup.1 or 5.5% IACS.
5. The improved electrically conductive cable in claim 1, wherein the first electrical wires are comprised of a single, solid core conductor, a multi-stranded conductor, a plurality of individually insulated conductors, or any other configuration known in the art.
6. The improved electrically conductive cable in claim 1, wherein the second electrical wires are comprised of a single, solid core conductor, a multi-stranded conductor, a plurality of individually insulated conductors, or any other configuration known in the art.
7. The improved electrically conductive cable in claim 1, wherein the first electrical wires are comprised of one or more conductors that are round, oval, rectangular, square, foil, or any other shape known in the art.
8. The improved electrically conductive cable in claim 1, wherein the second electrical wires are comprised of one or more conductors that are round, oval, rectangular, square, foil, or any other shape known in the art.
9. The improved electrically conductive cable in claim 1, wherein the first and second electrical wires are physically separated and independent from each other.
10. The improved electrically conductive cable in claim 1, wherein the first and second electrical wires are further encased in a single insulating body.
11. The improved electrically conductive cable in claim 1, wherein the first and second electrical wires are not encased in a single insulating body but connected by a means of maintaining a static distance between the first and second wires.
12. The improved electrically conductive cable in claim 1, wherein said ends of the first and second electrical wires have connectors that are terminated in bare metal, RCA, XLR, spade lug, banana pin, or any other audio, video, or data connector known in the art.
13. A method for reducing frequency dependent energy loss and phase errors from end to end as a function of the frequency of audio-range signals conducted therein, the method comprising: obtaining a first electrical wire having a first end and an opposing second end and comprising of a first electrically conductive metal with a conductivity between 0 and about 3.2*10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% International Annealed Copper Standard (IACS), wherein the first electrically conductive metal includes a relative magnetic permeability between 0 and 2, and a second electrical wire having a first end and an opposing second end; and transmitting audio-range signals from the first end to the second end, wherein the frequency dependent energy loss and phase from the first end to the second end is a function of a frequency of the audio-range signals transmitted therein.
14. The method of claim 13, wherein the second electrical wire comprises a second electrically conductive metal with a conductivity between 0 and about 3.2*10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% International Annealed Copper Standard (IACS), wherein the second electrically conductive metal includes a relative magnetic permeability between 0 and 2.
15. The improved electrically conductive cable in claim 13, wherein the second electrical wire is a neutral or ground wire comprised of a second electrically conductive metal with a conductivity equal to or greater than 3.2*10.sup.6 (ohm-meter).sup.1 or 5.5% IACS.
16. The method of claim 15, wherein the first electrically conductive metal of the first electrical wire includes a relative magnetic permeability of about 1.
17. The method of claim 16, wherein the second electrically conductive metal of the second electrical wire includes a relative magnetic permeability of about 1.
18. The method of claim 15, wherein the first electrically conductive metal of the first electrical wire is physically separated and independent from the second electrically conductive metal of the second electrical wire.
19. The method of claim 15, wherein the first and second electrically conductive metals of the first and second electrical wires are formed as one shape of round, oval, rectangular, square and foil.
Description
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0029] These and/or other aspects of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
DESCRIPTION OF INVENTION
[0038] Reference will now be made in detail to the exemplary embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The exemplary embodiments are described below in order to explain the present general inventive concept by referring to the figures.
[0039] In the transmission line model, the electromagnetic wave flows in the dielectric material between the conductors at a high percentage of the speed of light. At the dielectric-conductor boundary, the wave penetrates the conductor radially along the entire surface area of the conductor where it is slowed and attenuated at a rate which is dependent upon the frequency of the electromagnetic wave and the conductivity and relative magnetic permeability of the conductor. This loss wave within the conductor induces a conduction current density axially along the length of the conductor but since the loss wave penetrates radially into the conductor, the field strength, and hence the current density, are highest at the surface and decay as the wave propagates toward the conductor center. This model shows that higher frequency waves, due to their higher attenuation rates, have greater field strengths and associated current densities closer to the outer edge or skin of a conductor and lower frequency waves appear to have a more uniform field strength and current density from edge to center.
[0040] The equation for the attenuation of a sinusoidal electric field E propagating over time t and in a direction z within a conductor of finite conductivity can be shown to be:
E=E.sub.0e.sup.z sin (tz)
where is defined as the attenuation constant; the distance travelled by the wave is governed by the phase constant
where is the wavelength of the field; and , (2f) radians/second, is the wave oscillation frequency.
[0041] Expressed in terms of electrical characteristics, the attenuation and phase constants can be defined by:
where
[0042] is conductivity, (ohm-meter)-1
[0043] is permittivity, (farad/meter)
[0044] is permeability, (henry/meter)
[0045] t is time, (second)
[0046] The depth of penetration, also known as the skin depth, is defined as the distance of propagation in which the energy of the wave has been attenuated by a factor of 1/e or about 8.69 dB or:
[0047] Also, at skin depth , the phase of the wave E, (z) will change by 1 radian (57.3 degrees).
[0048] The velocity v (meters/second) of wave propagation or penetration is:
[0049] In electrically conductive materials, >>. Therefore, the velocity of propagation of electromagnetic energy in a metal conductor can be written as:
[0050] Using the electrical characteristics of copper:
=5.8*10.sup.7 (ohm-meter).sup.1
=4*10.sup.7 henry/meter
[0051] The following Table 1 shows the skin depth and propagation velocity of an electromagnetic wave in copper at various audio frequencies:
TABLE-US-00001 TABLE 1 Frequency f Skin Depth Velocity v hertz millimeters meters/second 50 9.35 2.93 100 6.61 4.15 1,000 2.09 13.12 10,000 .66 41.50 20,000 .47 58.69
[0052] While the primary electromagnetic wave propagates along the dielectric at nearly the speed of light, the above table shows that this secondary electromagnetic wave penetrates the conductor nearly radially and travels at significantly lower speeds. This secondary wave constitutes an error or memory wave which results in energy loss and phases errors that are dependent upon wave frequency and the conductivity and size of the conductor.
[0053] This suggests that, for two conductors of the same conductivity, but different sizes or thicknesses, the smaller or thinner conductor will experience less frequency dependent energy loss and phase errors than the larger or thicker conductor.
[0054] Using the electrical characteristics of aluminum:
=3.54*10.sup.7 (ohm-meter).sup.1
=4*10.sup.7 henry/meter
[0055] The following Table 2 shows that the skin depth and propagation velocity of an electromagnetic wave in aluminum increase with aluminum's corresponding decrease in conductivity:
TABLE-US-00002 TABLE 2 Frequency f Skin Depth Velocity v hertz millimeters meters/second 50 11.96 3.75 100 8.46 5.32 1,000 2.67 16.81 10,000 .85 53.15 20,000 .60 75.17
[0056] This suggests that, for two conductors of the same size and shape, the conductor with the lower conductivity will experience less frequency dependent energy loss and phase errors than the conductor with higher conductivity.
[0057] The International Annealed Copper Standard (IACS) establishes a standard for the conductivity of commercially pure annealed copper. The standard was established in 1913 by the International Electrotechnical Commission. The Commission established that, at 20 C., commercially pure, annealed copper has a resistivity of 1.724110.sup.8 ohm-meter or 5.810.sup.7 (ohm-(or Siemens/meter) when expressed in terms of conductivity. For convenience, conductivity is frequently expressed in terms of percent IACS. A conductivity of 5.810.sup.7 S/m may be expressed as 100% IACS at 20 C. All other conductivity values are related back to this standard value of conductivity for annealed copper. Aluminum, with a conductivity of 3.54*10.sup.7 (ohm-m).sup.1 (or Siemens/meter) at 20 C. may be expressed as 61% IACS.
[0058] Note that the permeability of both copper and aluminum, for use in calculating the values in the above tables, is listed as: =4*10.sup.7 henry/m. This value is equal to the permeability constant 0 which is defined as the permeability of free space.
[0059] Relative magnetic permeability is defined as the ratio of the permeability of a specific material to the permeability of free space 0:
r=/0
where
[0060] r is the relative magnetic permeability
[0061] is permeability of the material (henry/m)
[0062] Copper is weakly diamagnetic with a relative magnetic permeability of r=0.999994. Aluminum is weakly paramagnetic with a relative magnetic permeability r=1.000022. As most materials, including electrically conductive metals, have a relative magnetic permeability of r1, it should be obvious that the very small differences in permeability of these electrically conductive metals will not produce any appreciable differences in frequency dependent energy loss or phase errors. However, it should also be obvious that the use of ferromagnetic materials, materials in which r>>1, will result in greatly reduced skin depth and propagation velocity values for electromagnetic waves and that cables using these highly magnetically permeable materials will experience significant frequency dependent energy loss and phase errors. As an example, for nickel, its relative magnetic permeability r>100. In the case of iron, r>5000.
[0063] Frequency dependent energy loss can also be described by Alternating Current (AC) resistance, of which skin depth is also a function. Direct Current (DC) resistance is only a function of conductivity and wire size.
[0064] The AC resistance (ohm/meter) of a circular wire is:
where
[0065] is conductivity, (ohm-meter)-1
[0066] is skin depth, (meters)
[0067] r is radius of circular wire, (meters)
[0068] The DC resistance (ohm/meter) of a circular wire is:
where
[0069] 94 is conductivity, (ohm-meter)-1
[0070] r is radius of circular wire, (meters)
[0071] The range of human hearing is generally described as 20 Hz to 20 kHz. Using the above conductivity value for copper, the following table 3 illustrates the change in AC resistance across the frequency range of human hearing and its percentage increase over DC resistance for a 12-gauge wire, a wire size commonly used in audio applications:
TABLE-US-00003 TABLE 3 Frequency f DC resistance AC resistance hertz ohms/meter ohms/meter % increase 20 .00503 .00503 0% 5,000 .00503 .005086 1% 10,000 .00503 .005815 15.6% 20,000 .00503 .007242 44.0%
[0072] Using the above conductivity value for aluminum, the following table 4 illustrates the change in AC resistance across the frequency range of human hearing and its percentage increase over DC resistance for a 12 gauge wire:
TABLE-US-00004 TABLE 4 Frequency f DC resistance AC resistance hertz ohms/meter ohms/meter % increase 20 .008246 .008246 0% 5,000 .008246 .008246 0% 10,000 .008246 .008555 3.7%.sup. 20,000 .008246 .01009 22.3%
[0073] This suggests that, for two conductors of the same size and shape, the conductor with the lower conductivity will experience less frequency dependent energy loss, compared to frequency independent losses, than the conductor with higher conductivity. This also suggests that, as conductivity decreases, a wire will begin to act more like a pure resistor, with no frequency dependent losses, across the range of human hearing.
[0074]
[0075]
[0076] In the present embodiment, the improved conductive cable according to the present general inventive concept is designed and configured to reduce and/or substantially eliminate errors within electromagnetic waveforms transmitted there through with minimum induced errors, distortions, or other undesirable alterations. The improved conductive cable according to the present general inventive concept utilizes a low conductivity cable which is in direct contravention to what a person skilled in the art would have and continues to use to resolve or address reducing electromagnetic waveform errors.
[0077] Referring now to
[0078] The first and second solid core metal conductors 102, 104 are of a metal or metal alloy with conductivity between 0 and about 3.2*10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% IACS at 20 C. and a relative magnetic permeability between 0 and 2. In an embodiment, the first and second solid core metal conductors 102, 104 are of a metal or metal alloy with conductivity of about 3.2*10.sup.6 (ohm-meter).sup.1 or about 5.5% IACS at 20 C. and a relative magnetic permeability r1.
[0079] Referring to
[0080] At step 204, the method 200 includes transmitting audio-range signals through the improved conductive cable 100, wherein a frequency dependent energy loss and phase error is a function of a frequency of the audio-range signals transmitted through the improved conductive cable 100.
[0081] The improved conductive cable 100 and method 200 according to the present general inventive concept improves upon conventional cables by increasing the radial transmission speed of the electromagnetic error wave in electrical cables in order to reduce the phase or timing errors in the signal.
[0082] The improved conductive cable 100 and method 200 according to the present general inventive concept also improves upon conventional cables by eliminating or substantially reducing frequency dependent energy loss across the frequency range of human hearing. Both improvements are achieved through the use of an improved electrical (i.e., conductive) cable, in any shape or geometry known in the art, with a metal conductor having a conductivity less than 3.2*10.sup.6 (ohm-meter).sup.1 or 5.5% IACS and relative magnetic permeability of r1.
[0083] Using the conductivity value of 5.5% IACS or =3.2*10.sup.6 (ohm-meter).sup.1 and relative magnetic permeability of r=1 for a hypothetical metal, the following Table 5 illustrates the change in AC resistance across the frequency range of human hearing and its percentage increase over DC resistance for a 12 gauge wire, a wire size commonly used in audio applications:
TABLE-US-00005 TABLE 5 Frequency f DC resistance AC resistance Hertz ohms/meter ohms/meter % increase 20 .09146 .09146 0% 5,000 .09146 .09146 0% 10,000 .09146 .09146 0% 20,000 .09146 .09146 0%
[0084] Using the above hypothetical metal, the following Table 6 shows the improvement in radial propagation velocity of an electromagnetic wave in the hypothetical metal over copper at various audio frequencies:
TABLE-US-00006 TABLE 6 Velocity in 5.5% IACS Frequency f Velocity in copper metal hertz meters/second meters/second 50 2.93 12.52 100 4.15 17.71 1,000 13.12 55.99 10,000 41.50 177.05 20,000 58.69 250.39
[0085] Table 6 demonstrates that the radial electromagnetic error wave velocity is dramatically increased in the hypothetical metal conductor. The increased error wave velocity will result in a corresponding decrease in phase or timing errors in the primary signal.
[0086] Referring to
[0087]
[0088] Referring to
[0089] Referring to
[0090] In the art, an audio interconnect cable consists of a pair of RCA, XLR, or similar connectors, each with one or more male or female positive pins and one or more male or female ground or neutral pins. Each of the first connector's pins is connected to the corresponding pin on the second connector using an insulated electrical wire.
[0091] In alternative embodiments, the improved conductive cable 100 may be comprised of a single, solid core conductor, a multi-stranded conductor, bundles of individually insulated conductors, or any other configuration known in the art. However, the present general inventive concept is not limited thereto.
[0092] In exemplary embodiments, the first and second solid core metal conductors 102, 104 may be round, rectangular or flat, or any other shape known in the art. However, the present general inventive concept is not limited thereto.
[0093] In the present embodiment, the first metal conductor 102 (positive) and the second metal conductor 104 (ground or neutral) are formed of a metal or metal alloy with a conductivity of less than 5.5% IACS at 20 C. and a relative magnetic permeability of r1.
[0094] The improved conductive cable 100 may be formed as a speaker cable consisting of one or more insulated positive wires and one or more insulated ground or neutral wires. These insulated wires may be physically separate from each other or, as is most often the case, encased in a single insulated body. Each positive and negative wire is individually terminated in a spade lug, banana plug, bare wire, or any other connector known in the art for connecting a wire to a binding post on an amplifier or a speaker. Wires may be comprised of a single, solid core conductor, a multi-stranded conductor, bundles of individually insulated conductors, or any other configuration known in the art.
[0095] The first and second metal conductors 102, 104 may be round, rectangular or flat, or any other shape known in the art. In this preferred embodiment, the positive and ground or neutral conductors are of a metal or metal alloy with conductivity less than 5.5% IACS at 20 C. and a relative magnetic permeability of r1.
[0096] In alternative embodiments, the improved conductive cable 100 may be formed as an audio interconnect cable consisting of a pair of RCA, XLR, or similar connectors, each with one or more male or female positive pins and one or more male or female ground or neutral pins. Each of the first connector's pins is connected to the corresponding pin on the second connector using an insulated electrical wire. Electrical wires may be comprised of a single, solid core conductor, a multi-stranded conductor, bundles of individually insulated conductors, or any other configuration known in the art. The conductors may be round, rectangular or flat, or any other shape known in the art. In some cases, for electrical safety, to minimize ground noise or ground loop hum, or for purposes of electromagnetic shielding, it is desirable for the ground or neutral wires to have very low DC resistance.
[0097] In this alternate embodiment, the positive conductors are of a metal or metal alloy with conductivity less than 5.5% IACS at 20 C. and a relative magnetic permeability of r1. In order to achieve low DC resistance, the ground or neutral conductors may be of a metal or metal alloy with conductivity greater than 5.5% IACS 20 C. and a relative magnetic permeability of r1.
[0098] In the art, a speaker cable consists of one or more insulated positive wires and one or more insulated ground or neutral wires. These wires may be separate from each other or, as is most often the case, encased in a single insulated body. Each positive and negative wire is individually terminated in a spade lug, banana plug, bare wire, or any other connector known in the art for connecting a wire to a binding post on an amplifier or a speaker. Wires may be comprised of a single, solid core conductor, a multi-stranded conductor, bundles of individually insulated conductors, or any other configuration known in the art. The conductors may be round, rectangular or flat, or any other shape known in the art. In some cases, for purposes of electromagnetic shielding, or to maximize amplifier damping factor, it is desirable for the ground or neutral wires to have very low DC resistance. In this alternate embodiment, the positive conductors are of a metal or metal alloy with conductivity less than 5.5% IACS at 20 C. and a relative magnetic permeability of r1. In order to achieve low DC resistance, the ground or neutral conductors may be of a metal or metal alloy with conductivity greater than 5.5% IACS 20 C. and a relative magnetic permeability of r1.
[0099]
[0100] Referring now to
[0101] The plurality of first and second solid core metal conductors 302, 304 are of a metal or metal alloy with conductivity between 0 and about 3.2*10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% IACS at 20 C. and a relative magnetic permeability between 0 and 2. In an embodiment, the plurality of first and second solid core metal conductors 302, 304 are of a metal or metal alloy with conductivity of about 3.2*10.sup.6 (ohm-meter).sup.1 or about 5.5% IACS at 20 C. and a relative magnetic permeability r1.
[0102] However, in alternative embodiments, the positive conductors are of a metal or metal alloy with conductivity less than 5.5% IACS at 20 C. and a relative magnetic permeability of 1. In order to achieve low DC resistance, the ground or neutral conductors may be of a metal or metal alloy with conductivity greater than 5.5% IACS 20 C. and a relative magnetic permeability of r1.
[0103] Referring now to
[0104] Further, as illustrated in
[0105] The plurality of first and second individually insulated stranded wire metal conductors 402, 404 are of a metal or metal alloy with conductivity between 0 and about 3.2*10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% IACS at 20 C. and a relative magnetic permeability between 0 and 2. In an embodiment, the plurality of first and second solid core metal conductors 402, 404 are of a metal or metal alloy with conductivity of about 3.2*10.sup.6 (ohm-meter).sup.1 or about 5.5% IACS at 20 C. and a relative magnetic permeability r1.
[0106] However, in alternative embodiments, the positive conductors are of a metal or metal alloy with conductivity less than 5.5% IACS at 20 C. and a relative magnetic permeability of r1. In order to achieve low DC resistance, the ground or neutral conductors may be of a metal or metal alloy with conductivity greater than 5.5% IACS 20 C. and a relative magnetic permeability of r1.
[0107] Referring now to
[0108] The first and second solid metal conductors 502, 504 are of a metal or metal alloy with conductivity between 0 and about 3.2*10.sup.6 (ohm-meter).sup.1 or between 0 and about 5.5% IACS at 20 C. and a relative magnetic permeability between 0 and 2. In an embodiment, the first and second solid rectangular shaped core metal conductors 502, 504 are of a metal or metal alloy with conductivity of about 3.2*10.sup.6 (ohm-meter).sup.1 or about 5.5% IACS at 20 C. and a relative magnetic permeability r1.
[0109] However, in alternative embodiments, the positive conductors are of a metal or metal alloy with conductivity less than 5.5% IACS at 20 C. and a relative magnetic permeability of r1. In order to achieve low DC resistance, the ground or neutral conductors may be of a metal or metal alloy with conductivity greater than 5.5% IACS 20 C. and a relative magnetic permeability of r1.
[0110] While the improved electrically conductive cable of the present invention as herein disclosed in detail is fully capable of obtaining the objects and providing the advantages and improvements herein before stated, it is to be understood that it is merely illustrative of a preferred embodiment and one of many alternative embodiments of the invention and that no limitations are intended to the details of the construction or design herein described other than as described in the appended claims.