POWER-SHARING NETWORK COMMUNICATIONS DEVICE

摘要

A set of network communications devices shares (48) available power among themselves to meet overall system power loading. An individual device (48) is configured to include a local power supply (28) delivering power to a local power bus (30) at a local supply voltage varied in response to a voltage control signal. A protection component (38) is connected between the local power bus (30) and an external power cable (18) used to connect the device to another device for sharing power. The protection component (38) provides an interruptible low- impedance DC path for carrying current based on direction and magnitude of a voltage difference between the local power bus (30) and the external power cable (18. Control circuitry (42 ) is used to: (a) drive a current - sharing bus connected among the devices to influence a value of a system current - sharing signal indicating a level of system power loading among the devices; (b) generate a difference signal indicating a difference between local power loading of the local power supply and the system power loading 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.