The power over Ethernet (registered trade mark) the dual mode detection null receiving electricity side equipment of the receiving electricity side

摘要

A system for providing power to a powered device (PD), is a methodology and a novel circuit for detecting PD. PD detection circuit detects a PD in the second mode by providing a detection voltage for detecting a PD in a first mode by providing a detection current to explore the PD, the probe the PD . I to determine if the PD is detected in both of the second mode and the first mode, control circuit, and PD is a device is enabled.