Passive POE (Power Over Ethernet) adapter, uses unused pairs of 100baseT network cable to transmit power to remote device.
DC jack center positive, 2.1 mm pin. RJ45 pins 4,5 = positive, RJ45 pins 7,8 = negative.
Passive POE does not comply with the IEEE 802.3af specification.
• To minimize cable losses, feed the highest allowed voltage, e.g. 18V. Demarc Technology has a nice POE voltage drop calculator - select 1 pair for correct results.Power = voltage * current.
• To avoid ground loops, ground should be referenced on the receiving end only, that is use a 2 prong (non grounded) AC adapter.