I'm looking at the POE Arduino board, what I would love to do is take that POE power use a relay and pull 12 volts (up to 4.5 watts) to flip a electric strike, and a RFID reader which will take anywhere from 5-15 volts at a peak of 121 ma
Is this possible with the Arduino POE ethernet board ?
You would have to tap into the power either at the PoE module, or hack the ethernet wire to pull power out there.
According the the PoE module datasheet here: http://arduino.cc/en/uploads/Main/PoE-datasheet.pdf It has 12v of output, even though the ethernet wire should be carrying something closer to 40 or 45 volts. This is assuming you have the PoE module listed here: http://store.arduino.cc/ww/index.php?main_page=product_info&cPath=6&products_id=148
Just tapping into the arduino's power will not do it because that is going through voltage regulators so only has max 5 volts of power on it.