A circuit for stealing power from an external system without interfering with a communication protocol includes a plurality of wiring connectors configured to receive a plurality of wires, where the plurality of wiring connectors receive a plurality of current levels set by the external system according to the communication protocol; a first voltage regulator to regulate a voltage on the plurality of wiring connectors at a plurality of voltage levels according to the communication protocol; a current monitor to measure the plurality of current levels received through the plurality of wiring connectors; a second voltage regulator that provides a current-limiting output; and a power converter that optimizes an amount of power stolen from the plurality of wiring connectors based on the current-limiting output.