Maintaining power to a powered device during a low power mode of the powered device

摘要

A powered device receives electrical power through a data transmission cable from a power supplying device that monitors a load on the data transmission cable and turns off the power to the load if the load is outside of a range. The powered device draws a first current at least part of a time during which the powered device is in a low power mode. The powered device is operable during the low power mode to draw a second current. And the powered device increases and decreases the second current to maintain a sum of the first current and the second current, or a level of a current into the powered device, at least at a minimum level for at least a portion of a cycle time.

主权项

1. A method of causing power to be maintained to a powered device during a low power mode of the powered device, comprising:
receiving electrical power by the powered device through a data transmission cable from a power sourcing device that monitors a load on the data transmission cable and turns off the power to the load if the load is outside of a range; reducing a first current drawn by the powered device at the powered device to put the powered device in the low power mode; and maintaining a level of a current into the powered device at least at a minimum level for at least a portion of a cycle time by changing a second current drawn by the powered device at the powered device in response to a monitored current value being different from a reference value, total current into the powered device being a sum of the first and second currents.