I'm not an EE. I'm a Software Engineer. I would like to build a small circuit that would leach power from an active 2.5v Ethernet line to charge a capacitor very slowly (over a timespan of 1-2 minutes). When the capacitor is fully charged, it would then discharge at 5.5v to power a circuit containing an Atmel chip and an I2C sensor. Q1) Is this possible? Q2) Would charging the capacitor block traffic over the Ethernet cable? Q3) Can anyone give me a rough idea what this circuit should look like and what the specs of the capacitor should be? Alternatively, can someone refer me to an EE who could design this for me?