Power transfer apparatus for concurrently transmitting data and power over data wires

• US 5,994,998 A
• Filed: 05/29/1997
• Issued: 11/30/1999
• Est. Priority Date: 05/29/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Burns, Lawrence M., Fisher, David A., Muther, Stephen E.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US08/865,016
• Time in Patent Office: 915 Days
• Field of Search: 340/310.01, 340/310.02, 340/310.08, 340/825.72, 370/490, 370/487, 370/419, 370/442, 375/257, 375/259, 307/126, 307/128, 307/127, 455/3.1, 455/3.3
• US Class Current: 375/258
• CPC Class Codes: H04B 2203/5437 Wired telephone
• CPC Class Codes: H04B 2203/5441 Wireless systems or telephone
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 2203/547 via DC power distribution
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 2203/5491 using filtering and bypassing
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

Electrical supply current, sufficient to power a wireless access point, is transmitted concurrently with a network data signal across a transmission line. A power and data coupler couples the network data signal and the power signal, received through a data input and a power input respectively, and transmits the coupled signal, to a distance of three meters or more, over the transmission line to a power and data decoupler. The power and data decoupler separates the power signal from the network data signal and supplies those signals to a power output port and a data output port, respectively, for use by a wireless access node. The power signal may be modulated at a low frequency relative to the frequency of the data signal, and the network data signal has a data transmission rate of one megabit/second or higher.

Claims

1. An apparatus for providing electrical power supply current to at least one network device, comprising:

a transmission line having a proximal end and a distal end, the distal end coupled to the network device, the transmission line adapted for transmission of a data signal over a distance of greater than 3 meters at a data rate of greater than 1 megabits per second, wherein the data signal corresponds to a local area network data signal;

a coupler coupled to the proximal end of the transmission line, the coupler having a data input and a power input, the coupler couples power supply current from the power input and the data signal from the data input to the transmission line; and

at least one decoupler coupled to the distal end of the transmission line, each of the at least one decoupler having a data output coupled to a corresponding one of the at least one network device and a power output coupled to the corresponding one of the at least one network device, each of the at least one decoupler supplies the data signal from the transmission line to the data output and power supply current from the transmission line to the power output, the power output being sufficient for operation of the at least one network device.

2. The apparatus of claim 1 wherein the transmission line provides a transmit path and supplies the data signal from the coupler to the decoupler, and the apparatus further including:

a second transmission line having a second proximal end and a second distal end, the second distal end coupled to the network device, the second transmission line adapted for transmission of a data signal over a distance of greater than 3 meters at a data rate of greater than 1 megabits per second, and the second transmission line providing a receive path and supplying the data signal from the decoupler to the coupler;

the coupler including a first receive path circuit coupled to the second proximal end, the coupler having a second data output, the coupler couples power supply current from the power input to the second transmission line, and the coupler supplies the data signal from the second transmission line to the data output;

the decoupler including a second receive path circuit coupled to the distal end of the second transmission line, the decoupler having a second data input coupled to the network device, the decoupler supplies the data signal from the data input to the second transmission line and power supply current from the second transmission line to the power output.

3. The apparatus of claim 1 wherein, the transmission line comprises two conductors, and the coupler supplies the first polarity component to the two conductors.

4. The apparatus of claim 2 wherein the power supply current has a first polarity component and a second polarity component, and the coupler supplies the first polarity component to the transmission line and the second polarity component to the second transmission line.

5. The apparatus of claim 4 wherein the power supply current includes alternating current, having a frequency of less than one hundred Hertz.

6. The apparatus of claim 4 wherein the power supply current includes direct current.

7. The apparatus of claim 1 wherein the transmission line comprises a twisted pair cable.

8. The apparatus of claim 2 wherein the transmission line and the second transmission line comprise a twisted pair cable.

9. The apparatus of claim 1 wherein the power supply current includes a first polarity component and a second polarity component, and the transmission line comprises two conductors, and the coupler includes a center tapped inductor having a first winding terminal coupled to one of the two conductors, a second winding terminal coupled to the other of the two conductors, and a center tap terminal connected to receive the first polarity component of the power supply current to distribute the first polarity component to the two conductors.

10. The apparatus of claim 9 wherein the data input comprises a differential input, and the coupler includes a transformer having a primary winding and a secondary winding, one of the primary winding and the secondary winding coupled across the differential input, and the other of the primary winding and the secondary winding coupled across the two conductors of the transmission line.

11. The apparatus of claim 10 wherein one of the primary winding and the secondary winding includes a capacitance for blocking DC components of the data signal.

12. The apparatus of claim 11 wherein the coupler includes an AC to DC converter coupled between the power input and the center-tapped inductor.

13. The apparatus of claim 1 wherein the power supply current includes a first polarity component and a second polarity component, and the transmission line comprises two conductors, and the decoupler includes a center tapped inductor having a first winding terminal coupled to one of the two conductors, a second winding terminal coupled to the other of the two conductors, and a center tap terminal coupled to decouple the first polarity component and transmit the first polarity component to the power output.

14. The apparatus of claim 13 wherein the data output comprises a differential output, and the decoupler includes a transformer having a primary winding and a secondary winding, one of the primary winding and the secondary winding coupled across the differential output, and the other of the primary winding and the secondary winding coupled across the two conductors of the transmission line.

15. The apparatus of claim 14 wherein one of the primary winding and the secondary winding includes a capacitance for blocking DC components of the data signal.

16. The apparatus of claim 14 wherein the decoupler includes an AC to DC converter coupled between the power output and the center-tapped inductor.

17. The apparatus of claim 1, wherein the operation of the at least one network device includes at least one of receiving, detecting, and processing the data signal.

18. The apparatus of claim 1, wherein the coupler includes:

at least one pair of data wires; and

an isolation transformer coupled with each pair of the at least one pair of data wires.

19. The apparatus of claim 18, wherein:

the local area network data signal is received from a communications network;

the data input corresponds to the local area network data signal; and

the isolation transformer is adapted to isolate the communications network from the power input.

20. The apparatus of claim 1, wherein:

the at least one decoupler inlcudes a plurality of decouplers; and

each decoupler is coupled to the transmission line, and each decoupler continues to supply the data signal from the transmission line to the data output when an additional decoupler is coupled to the transmission line.

21. The apparatus of claim 5, wherein the decoupler includes:

a voltage regulation device connected to the power output, the voltage regulation device having a positive terminal and a negative terminal; and

a rectifier having an output coupled with the voltage regulation device to increase isolation of the coupler from the decoupler.

22. A power transmission adapter for concurrently transmitting a power supply current and a data signal at distances over three meters comprising:

an electrical power port for receiving the power supply current;

a data communication port adapted for receiving the data signal, the data signal having a data transfer rate of one Megabits per second or higher, the data signal including a local area network data signal;

an output port having one or more data signal conductors adapted for transmitting the data signal; and

a coupling circuit, coupled to the electrical power input port, the data communication port and the output port, the coupling circuit couples the data signal and the power supply current to create a coupled signal and transmits the coupled signal to the data signal conductors, the data signal conductors are coupled to at least one network access point, the coupled signal includes a power output sufficient for operation of the network access point.

23. The power transmission adapter of claim 22 wherein the power supply current includes a first polarity component and a second polarity component, and the coupling circuit includes a first bias circuit and a second bias circuit, each bias circuit having an impedance substantially equal to zero to current with a frequency low frequency relative to a frequency of said data signal, and also having a substantially higher impedance to a network data signal with a data transfer rate of one Megabits per second or higher, and the first bias circuit and second bias circuit being both coupled to the data communication port and the data signal conductors of the output port, the first bias circuit further being coupled to the electrical power input port to receive the first polarity component, and the second bias circuit further being coupled to the electrical power input port to receive the second polarity component.

24. The power transmission adapter of claim 23 wherein each bias circuit includes a center-tapped inductor having a first winding and a second winding and a center tap, the first winding and the second winding of both center-tapped inductors being coupled to the data communication port and the data signal conductors of the output port, the center tap of the first center-tapped inductors being coupled to the electrical power input port to receive the first polarity component, and the center tap of the second center-tapped inductor being coupled to the electrical power input port to receive the second polarity component.

25. The power transmission adapter of claim 22 wherein the data communication port is adapted for receiving an Ethernet protocol conforming data signal.

26. The power transmission adapter of claim 22, including:

at least one pair of data wires; and

an isolation transformer coupled with each pair of the at least one pair of data wires.

27. The power transmission adapter of claim 26, wherein:

the local area network data signal is received from a communications network;

the data input corresponds to the local area network data signal; and

the isolation transformer isolates the communications network from the power supply current.

28. A power transmission adapter for decoupling a power supply current and a data signal from a coupled signal comprising:

an input port having one or more data signal conductors adapted for receiving the coupled signal;

an electrical power output port for transmitting the power supply current;

a data communication port for transmitting the data signal, the data signal having a data transfer rate of 1 Megabits per second or higher, the data signal including a local area network data signal; and

a decoupling circuit, coupled to the input port and the electrical power output port and the data communication port, and which decouples the data signal and the power supply current from the coupled signal and transmits the power supply current to the electrical power output port and the data signal to the data communication port, the power supply current is sufficient for at least one of receiving, detecting, and processing the data signal.

29. The power transmission adapter of claim 28 wherein the power supply current includes a first polarity component and second polarity component, and the decoupling circuit includes a first bias circuit and a second bias circuit, each bias circuit having an impedance substantially equal to zero to alternating current with a low frequency relative to a frequency of said data signal, each bias circuit having an impedance substantially equal to zero to direct current, and each bias circuit having a substantially higher impedance to a network data signal with a data transfer rate of 1 Megabits per second or higher, and the first bias circuit and the second bias circuit being coupled to the data communication port and the data signal conductors of the input port, and the first bias circuit being coupled to the electrical power output port to transmit the first polarity component to the electrical power output port, and the second bias circuit being coupled to the electrical power output port to transmit the second polarity component to the electrical power output port.

30. The power transmission adapter of claim 29 wherein each bias circuit includes a center-tapped inductor having a first winding, a second winding and a center tap, the first winding and the second winding of both center-tapped inductors being coupled to the data communication port and the data signal conductors of the input port, and the center tap of the first center-tapped inductor being coupled to the electrical power output port to transmit the first polarity component, and the center tap of the second center-tapped inductor being coupled to the electrical power output port to transmit the second polarity component.

31. The power transmission adapter of claim 30, wherein the power supply current includes direct current.

32. An apparatus for providing an electrical power signal to a wireless access point, the wireless access point providing wireless access to a plurality of wireless network devices, comprising:

a network transmission line having a proximal end and a distal end, the distal end coupled to the wireless access point, the network transmission line adapted for transmission of a local area network data signal to the wireless access point over a distance of greater than 3 meters, the local area network data signal being transmitted at greater than 1 megabits per second;

a coupler coupled to the proximal end of the network transmission line, the coupler having a data input and a power input, the coupler couples a power signal from the power input and the local area network data signal from the data input to the network transmission line; and

a decoupler coupled to the distal end of the network transmission line, the decoupler having a data output coupled to the wireless access point and a power output coupled to the wireless access point, the decoupler supplies the local area network data signal from the network transmission line to the data output and power signal from the network transmission line to the power output.