Patent ID: 8310089

Claim:
A network communications device for use as one of a set of power-sharing network communications devices, comprising: a local power bus; network communications operating circuitry constituting a local load connected to the local power bus to draw operating power therefrom; a local power supply having a power output connected to the local power bus to deliver power thereto at a local supply voltage, the local power supply being operative to vary the local supply voltage over a predetermined range in response to a voltage control signal supplied thereto; a protection component connected between the local power bus and an external power cable used in operation to connect the network communications device to another of the power-sharing network communications devices, the protection component providing an interruptible low-impedance direct current path for carrying current between the local power bus and the external power cable based on direction and magnitude of a voltage difference therebetween; and control circuitry operative to (a) drive an external current-sharing bus connected among the power-sharing network communications devices to influence a value of a system current-sharing signal carried by the current-sharing bus, the system current-sharing signal indicating a level of system power loading of a set of power supplies distributed among the power-sharing network communications devices, (b) generate a difference signal indicating a difference between a local power loading of the local power supply and the level of system power loading as reflected by the system current-sharing signal, and (c) generate the voltage control signal based on the difference signal to achieve a predetermined sharing of the system power loading by the local power supply.