REMOTE POWER SYSTEM FOR WIRELESS NETWORK ADAPTER UTILIZING UNUSED WIRE PAIRS IN ETHERNET NETWORK CABLE

Abstract: A power transmission system capable of transmitting power to a load through otherwise unused, twisted-pair conductors in a multi-conductor, data transmission cable, the system comprising a voltage source with first and second voltage terminals, the first voltage terminal coupled to at least one first conductor and the second voltage terminal coupled to at least one second conductor and a voltage regulator with input terminals and output terminals, the input terminals coupled to at least the first and second conductors respectively at a location remote from the voltage source terminals and the voltage output terminals electrically coupled to the load, the voltage regulator delivering a regulated DC voltage to the load.

Description: REMOTE POWER SYSTEM FOR WIRELESS NETWORK ADAPTER UTILIZING UNUSED WIRE PAIRS IN ETHERNET NETWORK CABLE Statement of Related Cases This application claims the benefit of U.S. Provisional Application No. 60/123,413 filed March 9, 1999. Field of the Invention This invention relates to the field of wired communication systems. More specifically, to communications systems that provide for simultaneous transmission of power and data information along the same cable bundle. Background of the Invention Ethernet networks allow communication between two or more data processing devices ("devices"). Most of these networks use a communication cable to link the devices together. Currently, there are three main types of wireline transport systems available for such communications: (1) twisted copper pair cable ("twisted pair"); (2) coaxial cable; and (3) fiber optic cable. Due to recent technological advances, communication between data processing stations is now possible through wireless networks using radio frequency transmission of data signals. Networks using twisted pair cable have historically predominated most local area network applications due to the lower costs associated with the use of this type of cable. Although other data transport systems may offer advantages such as speed and capacity over twisted pair cable, the use of twisted paid cable proliferates due to its lower cost and simplicity of installation. A substantial portion of the total number of local area networks in service today use twisted pair cable to conduct data between data processing stations. Most network data processing devices are located within a reasonable distance of an AC power outlet. These devices typically receive power through a separate power cord directly connected to an AC power outlet. Some devices use modular AC power converters mounted at the AC outlet to convert AC line power to that required by the device before the power travels though the smaller gauge power cord. Both of these methods of powering network devices require separate power cords to be used in addition to data communication cabling. In many applications, the requirement of connecting separate power and data cables to network devices is not problematic. In many modern office buildings, power outlets and network data ports are strategically positioned side-by-side on the wall to enable convenient connections. Not all network devices, however, can be conveniently positioned near available power sources By way of example, one such device is a Wireless Network Adapter ("Adapter") This Adapter is an Ethernet bridge device that interfaces between a wired network and a wireless network. The wireless side of the network uses specialized low power radios that operate in the microwave region of the RF spectrum. To gain maximum coverage, the Adapter is often mounted high on a wall or on a ceiling. Adapters may also be mounted in other out of the way places such as in warehouses or on the roofs of buildings. As such, it is often the case that an AC power outlet is not located near the desired placement of the Adapter. Traditional solutions to this problem have been to relocate the Adapter near an AC power outlet, which can limit the effectiveness of the Adapter; using a separate power extension cord to power the Adapter, which can be impossible in some applications and unsightly in others; or to install a new AC power outlet near the desired placement of the Adapter. This last solution can be very expensive considering the desirable placement for such devices. In the prior art, there are a number of examples where a single, two-conductor cable is used to carry both data and power. The single pair of wires connecting telephones carry both voice communication data and power. Underwater coaxial cable carries both data and the power used by the periodic repeaters that strengthen the data signal. Prior art solutions to the problem of joint transmission of data and power typically address their solutions to cables with only two conductive media. As a result, the design of the majority of the prior art pertaining to this invention is overly complex, costly and limited in functionality by the very nature of its two conductor design. The standard Ethernet twisted pair cable contains 4 (four) wire pairs. Two (2) of the wire pairs are used for data communications between network devices. The other 2 (two) wire pairs are not currently used in most applications. In an effort to transmit power and data on twisted pair cable, one prior art system uses a combination of data-transmitting and non data-transmitting conductors within the same cable to transmit power. This system exhibits a number of disadvantages. For example, this system uses at least one conductor to transmit both data and power. This combining of power and data increases the risk that one will be corrupted by the other and increases the complexity of the systems used to combine and extract the power and data, respectively. Further, this system is only capable of transmitting DC power on the twisted wire cable and therefore is limited in its application. See Sutterlin. U.S. Patent No. 5,148,144. Sutterlin is incorporated herein by this reference. Summary of the Invention It is therefore an object of this invention to provide an improved system for simultaneous transmission of power and data over twisted pair Ethernet cable that uses the unused twisted wire pairs exclusively for power transmission. It is a further object of this invention to provide an improved system for simultaneous transmission of power and data over twisted pair Ethernet cable that eliminates the cost, complexity and functional limitations of prior art systems. It is a further object of this invention to provide an improved system for simultaneous transmission of power and data over twisted pair Ethernet cable that is capable of transmitting either AC or DC power and is highly tolerant of voltage swings. It is a further object of this invention to provide an improved system for simultaneous transmission of power and data over twisted pair Ethernet cable that is insensitive to DC polarity when a DC power source is used. This invention results from the realization that the cost, complexity and functional limitations of prior art systems proposing simultaneous data and power transmission along Ethernet data communication cable can be eliminated by 1) using the unused conductors within the communications cable to carry power along the cable and 2) using a voltage regulator to lower and regulate the voltage of the power once the power has been transferred by the conductors within the cable. This invention features a power transmission system capable of transmitting power to a load through otherwise unused, twisted-pair conductors in a multi-conductor, data transmission cable. The system comprising a voltage source with first and second voltage terminals with the first voltage terminal coupled to at least one first conductor and the second voltage terminal coupled to at least one second conductor. The system further comprises a voltage regulator with input terminals and output terminals. The input terminals are coupled to at least the first and second conductors respectively at a location remote from the voltage source terminals. The voltage output terminals are electrically coupled to the load. The voltage regulator delivers a regulated DC voltage to the load. In one preferred embodiment, the voltage source delivers DC voltage. In another embodiment, a full wave bridge rectifier is added to the system. The input terminals of the rectifier are coupled to at least the first and second conductors in the data communication cable, respectively. The output terminals of the rectifier are coupled to the voltage regulator input terminals and poled to deliver positive voltage to the voltage regulator regardless of the polarity of the voltage source. This embodiment is contemplated to function using either an AC or DC power source. When an AC power source is used, the full wave bridge rectifier converts the AC voltage into a DC voltage. In yet another contemplated embodiment, the power transmission system further comprises a second voltage source and a second full wave bridge rectifier. The input terminals of the second full wave rectifier are coupled to the first and second voltage terminals of the second voltage source, respectively. The second full wave rectifier's output terminals are then coupled in parallel with the output terminals of the first full wave bridge rectifier, such that power from both voltage sources is available to the load through the voltage regulator. In one possible variation of an embodiment of this invention, a network power adapter using MJ8 connectors delivers voltage to the unused conductors of the network cable. In this embodiment, a low voltage power jack connects an AC power converter with the unused conductors of the communication cable. It is contemplated that at least two separate conductors be used to transmit voltage along the data transmission cable, but that as many unused conductors as exist be used for this purpose. Another embodiment uses a second voltage source. This second voltage passes through a second full wave rectifier. The output of the second full wave rectifier connects with the output of the first rectifier in parallel, such that power from both voltage delivery means is available to the load through the converting means. This invention discloses a method of transmitting power to a load through otherwise unused, twisted-pair conductors in a multi-conductor, data transmission cable. The basic steps of such method are: 1) delivering a voltage to the unused conductors of the communication line; and 2) converting the voltage across conductors into a regulated DC voltage. Another embodiment of this method further comprises the step of rectifying the voltage across the conductors before converting the voltage into a regulated DC voltage. This step eliminates the need to observe polarity when a DC voltage source is used. Yet another embodiment of the method disclosed by this invention, further comprises the steps of: 1) delivering a second voltage; 2) rectifying the second voltage; and 3) transmitting the rectified, second voltage in parallel with the first rectified voltage. This method allows power from both voltage sources to power the load. Brief Description of the Drawings The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as other features and advantages thereof, will be best understood by reference to the description which follows, read in conjunction with the accompanying drawings, wherein: FIG. 1 is a block diagram that illustrates the basic concept of this invention; FIG. 2 is another block diagram that illustrates another embodiment of this invention; FIG. 3 is a different block diagram that illustrates a further embodiment of this invention; FIG. 4 is another block diagram that illustrates an one preferred embodiment of this invention; and FIG. 5 is a flow diagram that illustrates the basic operation of one embodiment of this invention; FIG. 6 is a circuit schematic diagram that illustrates one preferred embodiment of this invention. Detailed Description of the Invention There is shown in FIG. 1 a block diagram illustrating power transmission system 10 capable of transmitting power to network device load 12 through otherwise unused, twisted pair conductors 14 in multi-conductor, data transmission cable 16. This system uses DC voltage source 18 with first and second voltage terminals to impart a voltage across unused, twisted pair conductors 14 in cable 16. First voltage terminal 20 is coupled to at least one first conductor 24 in cable 16 and second voltage terminal 22 is coupled to at least second conductor 26 in cable 16. Also shown in FIG 1 is voltage regulator 28 with input terminals 30, 32 and output terminals 34, 36 Input terminals 30,32 of voltage regulator 28 are coupled to at least first conductor 24 and second conductor 26 respectively at a location remote from terminals 20, 22 of voltage source 18 Output terminals 34, 36 of voltage regulator 28 are electrically coupled to network device load 12 such that voltage regulator 28 delivers a regulated DC voltage to load 12 A switching voltage regulator, linear voltage regulator, or other device known in the art to convert unregulated voltage into a regulated voltage is contemplated by this patent There is shown in FIG 2 a block diagram illustrating another embodiment of the power transmission system of this invention FIG 2 shows the power transmission system further comprising full wave bridge rectifier 38 with a pair of input terminals 40, 42 and a pair of output terminals 44,46 Input terminals 40, 42 are coupled to at least first conductor24 and second conductor 26 respectively Output terminals 44, 46 are coupled to input terminals 30,32 of voltage regulator 28 and are poled to deliver positive voltage to voltage regulator 28 regardless of the polarity of voltage source 18 As is illustrated in the drawing and unlike prior art systems, either an alternating or direct current voltage source may be used for voltage source 18 When voltage source 18 delivers DC voltage, full wave bridge rectifier 28 functions primarily as a polarity neutra zer thereby obviating the need to correct polarity errors with respect to DC voltage source 18 When voltage source 18 delivers AC voltage, full wave bridge rectifier 28 functions as a AC to DC converter There is shown in FIG 3 another block diagram illustrating a further embodiment of the power transmission system of this invention FIG 3 shows the power transmission system further comprising second voltage source 48 with first and second voltage terminals 50, 52 Also included in FIG 3 is second full wave bridge rectifier 54 with a pair of input terminals 56, 58 and a pair of output terminals 60,62 Input terminals 56, 58 are coupled to the first and second voltage terminals 50, 52, respectively, of second voltage source 48 As shown, output terminals 60, 62 of second full ' wave rectifier 54 are coupled in parallel with output terminals 44, 46 of first full wave bridge rectifier 38. This connection allows redundant or alternative power from both voltage sources 18, 48 to be available to load 12 through voltage regulator 28. This arrangement further provides isolation between the two power sources such that any voltage provided from one source will be electrically isolated from the other source. There is shown in FIG. 4 a block diagram depicting one embodiment of the present invention. This embodiment relates to a particular application of the invention to provide power and data in a single Ethernet twisted wire cable to a Wireless Network Adapter. This embodiment includes additional steps and components beyond the basic invention that improve the resulting performance of the system. These additional steps and components are in no way necessary or a limitation of the disclosed, claimed invention. Power is provided by an AC line source and converted by power converter 64. This converter converts AC line voltage to lower AC voltage or DC current. The voltage limits for the current implementation is 8 (eight) to 60 (sixty) volts DC or 10 (ten) to 30 (thirty) volts AC. The 30 (thirty) volt AC limit is dictated by regulatory requirements. In this embodiment, voltage output from power converter 64 is introduced onto the unused conductors of network interface cable 16. Network interface cable transmits data from network switch 70. Network switch 70 is used only as an example, other data sources such as a repeater can easily be substituted for switch 70. In this embodiment, cable 16 consists of 4 (four) twisted wire pairs. These cables are commonly constructed with EIA Category 3 or Category 5 cable. MJ8 connector 72 (sometimes called an RJ-45) connects Wireless Network Adapter 73 to cable 16. This connector allows easy connection between cable 16 and Adapter 73, but any suitable connection means are contemplated. For the purposes of this disclosure, the data conductors should be considered coupled to any appropriate data reception componentry, in this case to Ethernet Controller 80 The power conductors are coupled to four-line ferπte filter 76 This filter provides RF isolation between the Wireless Network Adapter and the outside environment From ferrite filter 76, the power signal is routed through full wave bridge rectifier 38 In this embodiment, full wave bridge rectifier 38 performs the following functions (1) for DC power sources, it eliminates the need for observing polarity at the voltage source and (2) for AC power sources, it provides the first step in converting the AC signal into the DC voltage required by Wireless Network Adapter 73 Alternate power is provided in this embodiment by a second AC line source located nearby Wireless Network Adapter 73 Like the first AC line source, the second source is converted by power converter 64 This converter converts AC line voltage to lower AC voltage or DC current The voltage limits for the current implementation is 8 (eight) to 60 (sixty) volts DC or 10 (ten) to 30 (thirty) volts AC The 30 (thirty) volt AC limit is dictated by regulatory requirements Converted power from power converter 64 is routed into Wireless Network Adapter 73 through local power connector 74 This connector is a coaxial power connector that provides a local power connection to Wireless Network Adapter 73 From local power connector 74, the power routes through ferrite filter 76 and bridge rectifier 54 The two bridge rectifiers 38, 54 are connected in parallel to allow the AC or DC voltages from the two sources to provide redundant power to Wireless Network Adapter 73 Further, this arrangement provides isolation between the two sources One voltage source is always isolated from the other through back-biased rectifiers Input filter capacitor 78 is attached to the DC output of full wave bridge rectifiers 38 and 54 One application uses a high value aluminum filter capacitor Filter capacitor 78 helps remove the AC component from an AC power signal when an AC power source is used The parallel outputs of bridge rectifiers 38, 54 are passed into switching voltage regulator 28. Switching voltage regulator 28 performs three functions: (1) it provides a regulated 5 (five) volt output to the logic circuitry of Wireless Network Adapter 73; (2) it provides a highly efficient mechanism of converting a wide range, unregulated input voltage to the regulated 5 (five) volts required by Wireless Network Adapter 73; and (3) it provides the final conversion of an AC voltage input to a regulated DC voltage output. Although this embodiment uses a switching voltage regulator to convert the transmitted power into a regulated 5 volt output, the use of other types of voltage regulators, such as a linear voltage regulator, is contemplated. Also contemplated is using the voltage regulator to provide a regulated output at a level other than 5 volts. There is shown in FIG. 5 a flow diagram of the basic steps of one embodiment of this invention. The first step shown in FIG. 4 is combining Ethernet data and unit power 64. This step refers to applying the voltage source across the unused conductors in the Ethernet communication cable. The next step performed is "network cable between power adapter and unit," labeled 16 in the diagram. This step indicates that both data and power travel along the same communication cable between the junction where power is introduced onto the cable and the point where power and data is extracted from the cable. The next step in the diagram is labeled "unit interface - cable fuse and ferrite filter" or number 68 in the diagram. This block refers to the subsequent steps in one embodiment wherein the power signal passes through fuses and ferrite filters. The fuses function as protection against over-current conditions and the ferrite filters provide RF isolation between the outside environment and the load. Next, the power signals passes through bridge rectifier 38. As stated above, this step eliminates the need to observe polarity when using DC voltage power sources and provides the first step in converting an AC power signal into the regulated DC power signal used by the load. Following bridge rectifier 38, the power signal passes input filter capacitor 78. As stated above, this capacitor or similar device helps filter the DC voltage from a DC voltage signal and helps remove the AC component from an AC power signal. Finally, the power signal passes into switching voltage regulator 28. Switching voltage regulator 28 provides a regulated DC voltage output to the load. This device provides a highly efficient mechanism of converting a wide range of unregulated input voltages into the required DC voltage. Finally, switching voltage regulator 28 provides the final conversion of AC voltage input into a regulated DC voltage when AC power supplies are used. Although this embodiment uses a switching voltage regulator to convert the transmitted power into a regulated 5 volt output, the use of other types of voltage regulators, such as a linear voltage regulator, is contemplated. Also contemplated is using the voltage regulator to provide a regulated output at a level other than 5 volts. There is shown in FIG. 6 a circuit schematic diagram that illustrates one preferred embodiment of this invention. Many of the same components shown in this diagram are the same or similar to those illustrated in the previous drawings. This drawing includes further detail and is considered the best mode of the present invention. Additional components are in no way necessary or a limitation of the disclosed, claimed invention. Power is provided by an AC line source and converted by power converter 64. This converter converts AC line voltage to lower AC voltage or DC current. The voltage limits for the current implementation is 8 (eight) to 60 (sixty) volts DC or 10 (ten) to 30 (thirty) volts AC. The 30 (thirty) volt AC limit is dictated by regulatory requirements. Voltage output from power converter 64 is introduced onto the unused conductors of network interface cable 16 using network power adapter 66. Within network power adapter 66 is low voltage power jack 82. This jack provides a convenient connection point for power input to network power adapter 66. From low voltage power jack 82, the power signal enters network interface cable 16 through MJ8 connector 72. Note that in this embodiment the power signal is split between 4 (four) total conductors within network cable 16. This configuration uses more conductive media for power transmission and is therefore capable of transmitting the above mentioned limits of 8 (eight) to 60 (sixty) volts DC or 10 (ten) to 30 (thirty) volts AC. Power transmission within these ranges has been successfully tested up to 200 meters through network cable 16, although the lOBaseT Ethernet standard officially supports only 100 meters. Data transmission is represented at the top of the drawing. User network 70 transmits data signals through two interconnecting MJ8 connectors 72 into network cable 16. The data source for user network 70 can be a network switch, repeater or other network communication device. Network cable 16 consists of 4 (four) twisted wire pairs. These cables are commonly constructed with EIA Category 3 or Category 5 cable. A third MJ8 connector 72 connects Wireless Network Adapter 73 to cable 16. This connector allows easy connection between cable 16 and Adapter 73, but any suitable connection means are contemplated. For the purposes of this disclosure, the data conductors should be considered coupled to any appropriate data reception componentry, in this case to Wireless Network Adapter Ethernet controller 80. The power conductors are coupled through separate, parallel fuses 84 to four-line ferrite filter 76. The fuses provide input power over-current protection for AC power converter 64 and network cable 16 . Filter 76 provides RF isolation between Wireless Network Adapter 73 and the outside environment and prevents RF noise generated by Wireless Network Adapter 73 from conducting onto network cable 16. From ferπte filter 76, the power signal is routed through full wave bridge rectifier 38 In this embodiment, full wave bridge rectifier 38 performs the following functions (1) for DC power sources, it eliminates the need for observing polarity at the voltage source and (2) for AC power sources, it provides the first step in converting the AC signal into the DC voltage required by Wireless Network Adapter 73 Alternate power is provided in this embodiment by a second AC line source located nearby Wireless Network Adapter 73 Like the first AC line source, the second source is converted by power converter 64 This converter converts AC line voltage to lower AC voltage or DC current The voltage limits for the current implementation is 8 (eight) to 60 (sixty) volts DC or 10 (ten) to 30 (thirty) volts AC The 30 (thirty) volt AC limit is dictated by regulatory requirements Converted power from power converter 64 flows into Wireless Network Adapter 73 through local power connector 74 This connector is a coaxial power connector that provides a local power connection to Wireless Network Adapter 73 From local power connector 74, the power routes through separate parallel fuses 84, ferπte filter 76 and second full wave bridge rectifier 54 The fuses provide input power over-current protection for AC power converter 64 Filter 76 provides RF isolation between the Wireless Network Adapter and the outside environment Second full wave bridge rectifier 54 performs the following functions (1) for DC power sources, it eliminates the need for observing polarity at the voltage source and (2) for AC power sources, it provides the first step in converting the AC signal into the DC voltage required by Wireless Network Adapter 73 The two bridge rectifiers 38, 54 are connected in parallel to allow the AC or DC voltages from the two sources to provide redundant power to Wireless Network Adapter 73 Further, this arrangement provides isolation between the two power sources One voltage source is always isolated from the other through back-biased rectifiers Input filter capacitor 78 attaches to the DC output of full wave bridge rectifiers 38 and 54. One embodiment uses a high value aluminum filter capacitor as input filter capacitor 78. Filter capacitor 78 helps remove the AC component from an AC power signal when an AC power source is used. The parallel outputs of bridge rectifiers 38, 54 are passed into switching voltage regulator 28. Switching voltage regulator 28 performs three functions: (1) it provides a regulated output voltage to the logic circuitry of Wireless Network Adapter 73, in this case 5 volts, but other voltage levels are contemplated in other embodiments; (2) it provides a highly efficient mechanism of converting a wide range, unregulated input voltage to the regulated 5 (five) volts required by Wireless Network Adapter 73; and (3) it provides the final conversion of an AC voltage input to a regulated DC voltage output. Switching voltage regulators are well known and similar, equivalent mechanisms are contemplated herein. The DC voltage output from switching voltage regulator 28 flows to network device load 12 as needed. The present invention overcomes the limitations of the prior art systems of simlultaneous power and data communications over a single communications cable. This invention is more simple, less expensive and more efficient than prior art systems proposing simultaneous data and power transmission along Ethernet data communication cable. This invention betters the present state of the art in that it: 1) uses the unused conductors within the communications cable to carry power along the cable; 2) is capable of transmitting AC or DC power along the communications cable; 3) is insensitive to DC polarity when DC voltage sources are used; 4) is highly tolerant of to voltage swings, including those that can result from long power transmission through narrow gauge conductors and 5) allows the use of redundant power sources to power a network device such as a Wireless Network Adapter.

Claims: I hereby claim: 1. A power transmission system capable of transmitting power to a load through otherwise unused, twisted-pair conductors in a multi-conductor, data transmission cable, the system comprising: a voltage source with first and second voltage terminals, the first voltage terminal coupled to at least one first conductor and the second voltage terminal coupled to at least one second conductor; and a voltage regulator with input terminals and output terminals, the input terminals coupled to at least the first and second conductors respectively at a location remote from the voltage source terminals and the voltage output terminals electrically coupled to the load, the voltage regulator delivering a regulated DC voltage to the load. 2. The power transmission system of claim 1 wherein the voltage source delivers DC voltage. 3. The power transmission system of claim 1 further comprising a full wave bridge rectifier with a pair of input terminals and a pair of output terminals, the input terminals coupled to at least the first and second conductors respectively and the output terminals coupled to the voltage regulator input terminals and poled to deliver positive voltage to the voltage regulator regardless of the polarity of the voltage source. 4. The power transmission system of claim 3 wherein the voltage source delivers DC voltage. 5. The power transmission system of claim 3 wherein the voltage source delivers AC voltage and the full wave bridge rectifier converts this AC voltage to DC voltage. 6. The power transmission system of claim 3 further comprising: a second voltage source with first and second voltage terminals; a second full wave bridge rectifier with a pair of input terminals and a pair of output terminals, the input terminals coupled to the first and second voltage terminals of the second voltage source, respectively, and the output terminals coupled in parallel with the output terminals of the first full wave bridge rectifier, such that power from both voltage sources is available to the load through the switching voltage regulator. 7. A power transmission system capable of transmitting power to a load through otherwise unused, twisted-pair conductors in a multi-conductor, data transmission cable, the system comprising: means for delivering voltage to the conductors, the voltage delivery means comprising first and second voltage terminals, the first voltage terminal coupled to at least one first conductor and the second voltage terminal coupled to at least one second conductor; and means for converting the voltage across the first and second conductors into a regulated DC voltage, the converting means comprising input and output means, the input means coupled to at least the first and second conductors respectively at a location remote from the voltage delivery means, the output means coupled to the load. 8. The power transmission system of claim 7 wherein the voltage delivery means delivers DC voltage. 9. The power transmission system of claim 7 further comprising means for rectifying the voltage across the conductors, the rectifying means comprising input means and output means, the input means coupled to the first and second conductors respectively, the output means coupled to the input means of the converting means and poled to deliver positive voltage to the converting means regardless of the polarity of the voltage delivery means. 10. The power transmission system of claim 9 wherein the voltage delivery means delivers DC voltage. 11. The power transmission system of claim 9 wherein the voltage delivery means delivers AC voltage and the rectifying means converts this AC voltage to DC voltage. 12. The power transmission system of claim 9 further comprising: a second means for delivering voltage, the second voltage delivery means comprising first and second voltage terminals; a second means for rectifying voltage, the second rectifying means comprising a pair of input terminals and a pair of output terminals, the input terminals coupled to the first and second voltage terminals of the second voltage delivery means respectively, and the output terminals of the second rectifying means coupled in parallel with the output terminals of the first rectifying means, such that power from both voltage delivery means is available to the load through the converting means. 13. A method of transmitting power to a load through otherwise unused, twisted-pair conductors in a multi-conductor, data transmission cable, the method comprising: delivering a voltage to the conductors, the voltage delivered across at least one first conductor and at least one second conductor; and converting the voltage across the first and second conductors into a regulated DC voltage. 14. The method in accordance with claim 13 further comprising the step of: rectifying the voltage across the conductors before converting the voltage into a regulated DC voltage. 15. The method in accordance with claim 14 further comprising the steps of: delivering a second voltage; rectifying the second voltage; and transmitting the rectified second voltage in parallel with the first rectified voltage, such that power from both voltage sources is available to power the load.

Inventors: ALBRIGHT LOREN O, ALBRIGHT, LOREN, O.
Applicants: ALBRIGHT LOREN O, ALBRIGHT, LOREN, O.
Application year: 2000
Main classification: H04L25
IPC codes: H04B3, H04L25