Power Device Of Power Over Ethernet System Design

Base on the launch of the IEEE 802. 3af standard in June 2003, "Power over Ethernet System (PoE) "is designed. This project through five ordinary Category UTP to provide DC for LAN equipments. To do this can eliminate the AC transformer of equipment, simplify integrated wiring works and reduce network construction costs. Also Through UPS power supply for LAN. Network equipments off the impact of the blackouts from the power grid, same like the telephones can still work in the power cut. The third advantage of PoE technology is that it can improve security, because the networks only supply power for the needed equipment.PoE power supply system composed of power supply equipment (PSE) and electrical used power equipment (PD). PSE provide 48V to network, allow 13W maximum power for each of the electrical equipment. Five-category cable contains four pairs of lines (eight lines). The standard Ethernet equipment only uses two pairs of lines (four lines), leisure of two pairs. Two spare pairs of line are used to supply power in IEEE 802. 3af. Therefore, transmitting electricity must be low enough to ensure that it will not burn the thin metal wire, also cannot make any implications to adjacent non- shield lane transmitting data signals. PD uses the LTC4267 chips of Technology Corp. Circuit designation is made a number of amelioration, makes system use and installation more convenient, also improves the stability and performance.