An electromagnetic wrap device and method for the control of transmission line reactances (combination of capacitance, inductance, and resistivity).
Transmission lines are used in a myriad of applications from within small handheld electronics transferring communication signals to large power systems transferring large amounts of power. In its simplest form, a transmission line is merely a conductor of electricity from one point (a source) to another (load). Transmission lines may be used for alternating current or direct current where deleterious alternating current surges differing from the fundamental frequency generated by the source may be induced to exist. The elements of the transmission line that allow development of such deleterious surges are the inductance, capacitance, and resistance inherent in the physical characteristics of the transmission line. These physical characteristics allow modes of the frequency components in the surges to induce reactances whose vector sums with the resistance of the transmission line result in an impedance upon which the voltage and current surges are developed. Voltage surges can break down insulation in the system, incapacitating a system by creating electrical shorts. Current surges also incapacitate a system by destroying control elements; switches, fuses, transistors, diodes, etc.
Ideally, transmission lines transfer signals without loss and without alteration of signal information content. If the transmission line characteristics are not optimized for the system, the received signals may be significantly altered, even over relatively short distances. Worse, even when, the transmission line characteristics are optimized, they may allow damaging resonances to form within the transmission line resulting in the aforementioned surges of line current and/or voltage.
For example, the Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTMS) at INL (Idaho National Laboratory) uses a coaxial style of transmission line to carry swept high-frequency power (50 Hz to 4 MHz) to metal plates of an ion cyclotron resonance (ICR) cell within a high vacuum and within the strong (7-Tesla) field of a superconducting magnet. This transmission line is severely constrained by two phenomena. First, if the transmission line has too little line capacitance (less than 60 pf), damaging resonances can occur at high frequencies within the transmission line resulting in reflected voltage surges which can puncture the metal-oxide-semiconductor gate structures of FETs (field-effect-transistors) used in the FTMS. Second, if the transmission line has too much capacitance (greater than 100 pf), the current demanded by the combined transmission line and load capacitance exceeds the current limit of the FETs resulting in their destruction.
Another example is the use of stepper motors to control the position of weldments and/or welding torches in a remote, high radiation field, automated process such as that designed for use in Yucca Mountain. State-of-the-art welding systems cannot currently extend beyond approximately 100 feet from their controllers due to the build-up of damaging resonances resulting in the breakdown of insulation in the motors and transmission lines. The need to maintain and operate the controllers in a minimal radiation field for protection of their operators begs for a solution to allow extending the cable length.
Various methods are used to adjust the line reactance (combination of capacitance, inductance, and resistivity) of a transmission line. Obviously, the length or diameter of the wire or the type of insulating material used in a transmission line may be altered to adjust capacitance of the transmission line. Unfortunately, in many instances, these may not be readily changeable or may already be optimized.
Various components may also be added to a transmission line such as capacitors and/or inductors to form filters which seek to control the allowable modes of the frequency components thereby minimizing potential surges. Unfortunately, when capacitors or inductors are used, they act as voltage dividers reducing the voltage transmitted through the transmission line.
Therefore, there exists a need for a device and method for altering the effects of reactive components of a transmission line without substantially altering the transmission line's physical characteristics or reducing the strength of the signal transmitted.
An electromagnetic wrap device and method for altering the line reactance of a transmission line having a transmission line, a first floating conductor and a grounding conductor. The first floating conductor is positioned at least partially between and electrically insulated from the transmission line and the grounding conductor. A source and a load are connected at opposite ends of the transmission line.
a depicts an end view of a preferred embodiment of an electromagnetic wrap having a first floating conductor completely surrounding the length of a transmission line; and a grounding conductor completely surrounding the length of the first floating conductor.
b depicts a perspective view of a preferred embodiment of an electromagnetic wrap having a first floating conductor completely surrounding the length of a transmission line; and a grounding conductor completely surrounding the length of a first floating conductor.
a depicts an exploded view of one embodiment of an electromagnetic wrap implementing the circuit diagram shown in
b depicts the circuit diagram for the embodiment of an electromagnetic wrap shown in
a depicts an exploded view of one embodiment of an electromagnetic wrap implementing the circuit diagram shown in
b depicts the circuit diagram for the embodiment of an electromagnetic wrap shown in
a depicts an exploded view of one embodiment of an electromagnetic wrap implementing the circuit diagram shown in
b depicts the schematic for the circuit created by the embodiment of an electromagnetic wrap shown in
An electromagnetic wrap device and method for altering the line reactance (combination of capacitance, inductance, and resistivity) of a transmission line having a transmission line, a first floating conductor and a grounding conductor. The first floating conductor is positioned at least partially between and electrically insulated from the transmission line and the grounding conductor. A source and a load are connected at opposite ends of the transmission line.
The transmission line 1 is electrically connected to a first node 9 and a second node 11 at opposite ends. The first node 9 and a second node 11 preferably represent a source and a load, respectively. The grounding conductor 5 is electrically connected to earth-ground 15.
The transmission line 1 line reactance can be adjusted by adjusting the properties (material, shape, dimensions, etc.) of the transmission line 1, first floating conductor 3, grounding conductor 5, the first insulator 7, the second insulator 8, or a combination thereof.
The transmission line 1 transmits an electrical signal between the first node 9 and the second node 11. Preferably, the transmission line 1 is an electrically conductive wire, pipe or any other electrical conductor. Although only one transmission line 1 is depicted in
The first floating conductor 3 is electrically floating and therefore is electrically isolated from voltage sources and drains (contrary to a coaxial cable or a faraday cage). Preferably, the first floating conductor 3 is selected to optimize the line reactance of the transmission line 1 while also accounting for the size and weight of the entire system. Preferably, the first floating conductor 3 is never electrically connected to earth-ground 15. In the alternative, the first floating conductor 3 is selectively electrically connected to earth-ground 15, whereby the transmission line 1 line reactance can be dynamically modified by grounding or floating the first floating conductor 3.
Preferably the first floating conductor 3 surrounds the transmission line 1 along the entire length of the transmission line 1. Although only one first floating conductor 3 is depicted in
The grounding conductor 5 is electrically connected to earth-ground 15. Any circuit will directly or indirectly be connected to earth-ground 15 through various surrounding electrically conductive or electrically insulating materials (e.g., shielding, casing, grounding circuits, air, wood, plastics, etc.) via capacitive coupling. The grounding conductor 5 is depicted in
Preferably, the grounding conductor 5 is an outer casing connected to earth-ground 15 in order to reduce noise internal or external to the casing. Although only one grounding conductor 5 is depicted in
Preferably, the grounding conductor 5 is connected to earth-ground 15 at only one location along the length of the grounding conductor 5 to avoid compromising the integrity of the shielding through a phenomenon known as a ground loop.
The earth-ground 15 is an electrical ground, preferably earth. Preferably, earth-ground 15 is obtained through the various surrounding electrically conductive or electrically insulating materials (e.g., wires, casing, grounding circuits, air, wood, plastics, etc.) eventually electrically connected to the ground. More preferably, earth-ground 15 is an electrical conductor buried underground (e.g., pipes, wires, etc.).
The first insulator 7 electrically insulates the first floating conductor 3 from the transmission line 1. The second insulator 8 electrically insulates the first floating conductor 3 and the grounding conductor 5. Preferably, the first insulator 7 and the second insulator 8 are each made of air, ceramics, glass, porcelain, composite, polymer materials, polyethylene, PVC, polymers, oil impregnated paper, Teflon®, silicone, modified ethylene tetrafluoroethylene (ETFE), compressed inorganic powders, or combinations thereof. Preferably, the first insulator 7 and the second insulator 8 are selected to optimize the line reactance of the transmission line 1 while also accounting for the size and weight of the entire system.
The first node 9 and the second node 11 are devices capable of sending or receiving a signal transmitted on the transmission line 1. Preferably, the transmission line 1 is optimized for the desired signal or power propagation between the first node 9 and the second node 11. In one embodiment, the first node 9, the second node 11, or both are sensitive to the line reactance of the transmission line 1.
In one embodiment, the first node 9 is a control system and the second node 9 is one or more sensors (e.g., thermistor, photodiode, tensiometer, wound coil etc.). For example, in one embodiment, the first node 9 is a computer and the second node 11 is a collection of metal plates of ion-cyclotron-resonance (ICR). In another embodiment, the first node 9 is a first computer and the second node 11 is a second computer. In yet another embodiment, the first node 9 is a power supply source and the second node 11 is an electrically resistive load, such as a motor, computer, light, or television. In yet another embodiment, the first node 9 is a computer and the second node 11 is a servo motor control.
a depicts an end view and
Although the first floating conductor 3 is depicted as a solid conductor in
Although
The grounding conductor 5 completely surrounds the transmission line 1, the first insulator 7, the first floating conductor 3, the second insulator 8. The grounding conductor 5 is electrically connected to earth-ground 15. Preferably, the grounding conductor 5 is one or more electrically conductive elements leadings to earth-ground (e.g., casings, tables, floors, pipes, etc.). Preferably, in this embodiment, the second insulator 8 is air.
In this embodiment, a first node 9, exterior to the grounding conductor 5, is connected to the first transmission line 1 by one or more external transmission wires 17. An aperture 19 in the grounding conductor 5 allows the one or more external transmission wires 17 to connect to the first transmission line 1 within the interior of the grounding conductor 5. The first transmission line 1 is electrically connected to the second transmission line 21. Finally, the second transmission line 21 is electrically connected to the second node 11.
The first transmission line 1 is completely surrounded by the first floating conductor 3 along the length of the first transmission line 1. A first insulator 7 is positioned between the first transmission line 1 and the first floating conductor 3. The second transmission line 21 is completely surrounded by the second floating conductor 23 along the length of the second transmission line 21. A third insulator 27 is positioned between the second transmission line 21 and the second floating conductor 23.
The first floating conductor 3 and the second first floating conductor 23 are electrically insulated from the grounding conductor 5 by a second insulator 8. Preferably, in this embodiment, the second insulator 8 is air.
In this embodiment, the grounding conductor 5 is preferably a casing for a larger device, which protects the larger device from electrical noise. The grounding conductor 5 is electrically connected to earth-ground 15.
In the alternative, the first node 9 may be positioned inside the grounding conductor 5. In this embodiment, it may be preferably to omit the one or more external transmission wires 17. In yet another alternative, the second node 11 may be positioned outside of the grounding conductor 5. In this embodiment, it may be preferably to include the one or more wires 17 additionally between the second node 11 and the transmission line 1 within the grounding conductor 5.
The one or more external transmission wires 17 transfer the signal produced by the first node 9 into the transmission line 1. The one or more wires 17 are electrical conductors, preferably, wires, coaxial cabling, electrically conductive tubes, the embodiment shown in
Using an embodiment similar to
The second transmission line 21 was a ⅛ inch copper tube. The second insulator 27 was ¼ inch fish-spine insulators separating the second transmission line 21 and the second floating conductor 23, therefore using air (vacuum) as an insulator. The second floating conductor 23 was a ⅜ stainless steel tube. The second transmission line 21 and the second floating conductor 23 each had a length of about 8 inches. The grounding conductor 5 was a steel encasing designed to prevent electrical noise from entering or exiting its interior.
By surrounding the first transmission line 1 with the first floating conductor 3 and the second transmission line 21 with the second floating conductor 23 the capacitance of the transmission system (one or more wires 17, first transmission line 1, and second transmission line 21) was lowered to about 90 pf.
A second insulator 8 electrically insulates the first floating conductor 3, the first electromagnetic wrap 20, the second electromagnetic wrap 30, and the third electromagnetic 40 wrap from the grounding conductor 5. Preferably, the second insulator 8 is air. The grounding conductor 5 is electrically connected to earth-ground 15.
A first node 9, exterior to the grounding conductor 5, is connected to the first transmission line 1 by one or more external transmission wires 17. An aperture 19 in the grounding conductor 5 allows the one or more external transmission wires 17 to connect to the first transmission line 1 within the interior of the grounding conductor 5. The first transmission line 1 is electrically connected the second node 11.
The first electromagnetic wrap 20 has an insulator 27 and a floating conductor 23. The insulator 27 of the first electromagnetic wrap 20 partially surrounds the first floating conductor 3 at a position unique from the second electromagnetic wrap 30 and the third electromagnetic wrap 40. The insulator 27 of the first electromagnetic wrap 20 is then surrounded, preferably fully surrounded, by the floating conductor 23 of the first electromagnetic wrap 20.
The second electromagnetic wrap 30 has an insulator 33 and a floating conductor 35. The insulator 33 of the second electromagnetic wrap 30 partially surrounds the first floating conductor 3 at a position unique from the first electromagnetic wrap 20 and the third electromagnetic wrap 40. The insulator 33 of the second electromagnetic wrap 30 is then surrounded, preferably fully surrounded, by the floating conductor 35 of the second electromagnetic wrap 30.
The third electromagnetic wrap 40 has an insulator 43 and a floating conductor 45. The insulator 43 of the third electromagnetic wrap 40 partially surrounds the first floating conductor 3 at a position unique from the first electromagnetic wrap 20 and the second electromagnetic wrap 30. The insulator 43 of the third electromagnetic wrap 40 is then surrounded, preferably fully surrounded, by the first floating conductor 45 of the third electromagnetic wrap 40.
The size and shape of the electromagnetic wraps (the first electromagnetic wrap 20, the second electromagnetic wrap 30, and the third electromagnetic wrap 40) may be the same or different. By adjusting the various sizes of the electromagnetic wraps, the line reactance of the transmission line 1 can be altered. Thus, the line reactance of the transmission line 1 could be designed to block (filter) or pass desired frequencies along the transmission line 1, whether for signal or power, more efficiently.
In one embodiment, one or more electromagnetic wraps are used in an inline filter design whereby deleterious frequencies traveling through the transmission line 1 are attenuated favoring desired frequencies. This may reduce the cost and size of various filters used in communications, as well as in power systems.
The one or more floating conductor patterns 50 finely tune the line reactance of the transmission line 1 by using one or more electromagnetic wraps that are then wrapped around the transmission line 1. One or more floating conductor patterns 50 are preferably printed as conducting films on the first insulator 7 and provide the desired line reactances of the transmission line 1.
The transmission line protective jacket 60 protects the various components from external influences, such as corrosion, electrical conductivity, etc.
a depicts one embodiment of an electromagnetic wrap having a design implementing the circuit shown in
In this embodiment, the first floating conductor 3 has a first conductive pattern 62 and a second conductive pattern 64. The first conductive pattern 62 and the second conductive pattern 64 are electrically separated except for a narrow conductive pattern 66. As the first floating conductive pattern 62 is wrapped around the first insulator 7 (and transmission line 1), the first conductive pattern 62 forms a first capacitor C1 (shown in
The first floating conductor 3 is preferably a substrate having the first conductive pattern 62 and the second conductive pattern 64. In the alternative, the first floating conductor 3 may be the first conductive pattern 62 and the second conductive pattern 64, deposited on the first insulator 7.
Likewise, the second conductive pattern 64 forms a second capacitor C2 (shown in
The gap between the first floating conductor 3 and the grounding conductor 5 produces a second set of capacitors, as shown in
a depicts one embodiment of an electromagnetic wrap having a design implementing the circuit shown in
The first conductive pattern 62 of the first floating conductor 3 and the second conductive pattern 64 of the second floating conductor 68 partially overlap each other between the transmission line 1 and the grounding conductor 5. This partial overlap generates a parallel connecting capacitor (C5 in
In the alternative, the first conductive pattern 62 of the first floating conductor 3 and the second conductive pattern 64 completely overlap creating a series connected capacitor. In yet another alternate embodiment, the first conductive pattern 62 of the first floating conductor 3 and the second conductive pattern 64 do not overlap at all creating two separate capacitor paths, such as the circuit diagram shown in
The first floating conductor 3 is preferably a substrate having the first conductive pattern 62. In the alternative, the first floating conductor 3 is the first conductive pattern 62 is deposited onto the first insulator 7.
Likewise, the second floating conductor 68 is preferably a substrate having the second conductive pattern 64. In the alternative, the second floating conductor 68 is the second conductive pattern 64 deposited onto the second insulator 8.
The first conductive pattern 62 forms a first capacitor C1 (shown in
The first conductive pattern 62 also forms a third capacitor C3 (shown in
The first conductive pattern 62 of the first floating conductor 3 and the second conductive pattern 64 of the second floating conductor 68 also form a fifth capacitor (C5) (shown in
a depicts an exploded view of one embodiment of an electromagnetic wrap preferably wrapped as shown in
The floating conductors (first floating conductor 3, the second floating conductor 68, the third floating conductor 56, and the fourth floating conductor 58), each have conductors which alter the line reactance of the transmission line 1. The floating conductors are each represented as a conducting pattern embedded in a non-conducting film in
The first floating conductor 3 and the fourth floating conductor 58 each have a first conductive pattern and a second conductive pattern connected by a narrow conductor (creating an inductor as described in
b depicts the schematic of the circuit created by the embodiment of an electromagnetic wrap shown in
The embodiment in
In the alternative power for the control system 93 may be obtained using other parasitic methods including inductive coupling through from the current flowing in the transmission line 1. This parasitic method also uses the diode bridge 90, which rectifies the current to direct current and stores power for the circuit in the small battery or capacitor 91. In the alternative, other power sources may be used, such as an external battery, or a simple ac/dc conversion device, such as a wall-wart.
The control system 93 is connected to the reflectometer 94. The reflectometer 94 monitors the flow and level of power in each direction of the transmission line 1 and produces a signal to the control system 93. The control system 93, using the input from the reflectometer 94, controls the switch 95, which electrically connects the third floating conductor 96 to earth ground 15 or electrically floats the third floating conductor 96.
In a preferred embodiment, the control system 93 is a microcontroller or an ASIC (Application Specific Integrated Circuit). Preferably, the control system 93 comprises an analog-to-digital converter which continuously monitors the voltage, the current (converted to a voltage signal), or a combination thereof of the transmission line 1 for reflections, resonations, surges, standing wave ratio, combinations thereof, etc. As known in the art, there are various methods of converting current into a voltage, such as reading the voltage of a known resistor or using a voltage-to-current op-amp design.
In the preferred embodiment, the control system 93 monitors the voltage, current or a combination thereof for reflections, resonations, surges, standing wave ratio, combinations thereof, etc. If for example a resonation is detected, the control system 93 may electrically float the third floating conductor 96 which change the electrical characteristics of the transmissions line 1 to attenuate the resonation. Likewise, if the standing wave ratio is undesirable, the control system may electrically ground or float the third floating conductor 96 to selectively alter the line reactance of the transmission line 1 thereby altering the standing wave ratio to desired levels.
In one alternate embodiment, the control system 93 comprise a display (e.g., a liquid crystal display), which displays to the user information such as voltage, current or a combination thereof (e.g., voltage/current waveforms, absolute, average, rms values, etc.). Preferably, the control system 93 displays one or more alerts to the user of the presence of undesirable resonance, standing wave ratio's etc., as the system alters the line reactance of the transmission line 1 using one or more of the above described electromagnetic wraps to attenuate such undesirable resonance, standing wave ratio's etc.
In a preferred embodiment, the reflectometer 94 is comprises a conductor positioned close enough to the transmission line 1 such that energy passing through the transmission line 1 is coupled to an output of the reflectometer 94, which is connected to the control system 93 for analysis.
The switch 95 is preferably optically coupled to the control system 93. The control system 93 uses the switch 95 to electrically ground or electrically float the third floating conductor 96 to change the reactive properties of the transmission line 1. In a preferred embodiment, the switch 95 is a switched electrically controlled by an optical receiver. The optical receiver is optically coupled to an electrical optical transistor electrically connected to the control system 93. This embodiment is preferable to avoid any electrical noise or surges from passing from the third floating conductor 96 into the control system 93. In the alternative, the reflectormeter 94 may also be similarly optically coupled to the control system 93.
The third floating conductor 96 contains one or more conductive patterns, such as shown in
In one embodiment, the floating conductor 96 is a conductor wrapped completely around and running partially along the length of the transmission line 1. In this embodiment, the control system 93 grounds or floats the third floating conductor 96 optimizing the line reactance of the transmission line 1 depending on the conditions of the transmission line 1 (e.g. reflections, load, standing wave ratio, etc.).
In another embodiment, the floating conductor 96 is a conductor wrapped comprising one or more of the electromagnetic wrap design creating the inductor design shown in
Preferably, a plurality of the third floating conductor 96 (either having similar designs or different designs) are positioned along the transmission line 1 in order to optimize the line reactance of the transmission line 1 depending on the conditions of the transmission line 1 (e.g., reflections, load, standing wave ratio, etc.).
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of an electromagnetic wrap for dealing with line reactance. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of an electromagnetic wrap and the appended claims are intended to cover such modifications and arrangements.
All publications and patent documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication or patent document were so individually denoted.
Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C.§112, ¶ 6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C.§11238, ¶ 6.
The United States Government has rights in this invention pursuant to Contract No. DE-AC07-05ID14517, between the U.S. Department of Energy (DOE) and the Battelle Energy Alliance.
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