Power control subsystem for powering a node over communication cabling

• US 20060091865A1
• Filed: 11/22/2005
• Published: 05/04/2006
• Est. Priority Date: 01/12/1999
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: Pincu, David, Korcharz, Dror, Lehr, Amir, Atias, Ilan
• Granted Patent: US 7,813,752 B2
• Time in Patent Office: Days
• US Class Current: 323/234
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: H02G 3/00 Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles installations of bus-bars H02G5/00; overhead installations H02G7/00; installations in or on the ground H02G9/00
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 19/08 with current supply sources at the substations generating ringing current H04M19/04

Abstract

A power control subsystem for controlling the supply of power transmitted to at least one node over communication cabling, the power control subsystem comprising circuitry to control current of a power transmitted over communication cabling, the circuitry being operative to provide current limiting for the power at a first threshold, and delayed over current cut-off of the power at a second threshold, the second threshold being lower than the first threshold.

Claims

1. A power control subsystem for controlling the supply of power transmitted to at least one node over communication cabling, the power control subsystem comprising circuitry to control current of a power transmitted over communication cabling, said circuitry being operative to provide current limiting for said power at a first threshold, and delayed over current cut-off of said power at a second threshold, said second threshold being lower than said first threshold.

2. A power control subsystem according to claim 1, wherein said circuitry comprises a current limiter and a switch.

3. A power control subsystem according to claim 2, wherein said circuitry further comprises a comparator, said current limiter being responsive to an output of said comparator.

4. A power control subsystem according to claim 3, wherein said circuitry further comprises a timer, said switch being responsive to said timer.

5. A power control subsystem according to claim 4, wherein said delayed over current cut-off is effected via said timer.

6. A power control subsystem according to claim 1, wherein said circuitry comprises a current limiter and a switch constituted of a single field effect transistor.

7. A power control subsystem according to claim 1, further comprising a management and control unit operative to interrogate the at least one node to which it is intended to transmit power over communication cabling in order to determine whether the node'"'"'s characteristics allow it to receive power over communication cabling.

8. A power control subsystem according to claim 7, wherein said circuitry operative to control current is responsive to said management and control unit, said circuitry operative to control current transmitting power to the at least one node responsive to said management and control unit'"'"'s determination that the node'"'"'s characteristics allow it to receive power over communication cabling.

9. A power supply subsystem for providing electrical power to at least node over communication cabling, the power supply subsystem comprising:

a means for receiving power;

a means for outputting power for transmission to the at least one node over communication cabling; and

circuitry arranged to control current of the power outputted via said means for outputting,

wherein said circuitry is operative to provide current limiting for said output power at a first threshold, and delayed over current cut-off of said output power at a second threshold, said second threshold being lower than said first threshold.

10. A power supply subsystem according to claim 9 wherein said circuitry comprises a current limiter and a switch.

11. A power supply subsystem according to claim 10, wherein said circuitry further comprises a comparator, said current limiter being responsive to an output of said comparator.

12. A power supply subsystem according to claim 11, wherein said circuitry further comprises a timer, said switch being responsive to said timer.

13. A power supply subsystem according to claim 12, wherein said delayed over current cut-off is effected via said timer.

14. A power supply subsystem according to claim 9, wherein said circuitry comprises a current limiter and a switch constituted of a single field effect transistor.

15. A power supply subsystem according to claim 9, further comprising a management and control unit operative to interrogate the at least one node to which it is intended to output power for transmission over communication cabling in order to determine whether the node'"'"'s characteristics allow it to receive power over communication cabling.

16. A power control subsystem according to claim 15, wherein said circuitry operative to control current is responsive to said management and control unit, said circuitry being operative to output power via said means for outputting power responsive to said management and control unit'"'"'s determination that the node'"'"'s characteristics allow it to receive power over communication cabling.

17. A method of controlling power supplied to at least one node over communication cabling comprising:

outputting a power for transmission to at least one node over communication cabling;

current limiting said output power at a first threshold; and

providing delayed over current cut-off of said output power at a second threshold, said second threshold being lower than said first threshold.

18. A method according to claim 17, further comprising prior to said outputting:

interrogating the at least one node to which it is intended to output power for transmission over communication cabling in order to determine whether the node'"'"'s characteristics allow it to receive power over communication cabling.

19. A method according to claim 18, wherein said stage of outputting is only in the event said interrogating determined that the node'"'"'s characteristics allow it to receive power over communication cabling.

20. A method according to claim 17, further comprising receiving an input power, said outputted power being derived from said received input power.