A power regulator includes an initial input, an output, a feedback input, and a comparison circuit. The initial input is configured to receive loop current at an insertion voltage. The output is configured to deliver charging power. The charging power changes at least partially in response to a change in the loop current. The comparison circuit is in electrical communication with the feedback input and is configured to regulate the insertion voltage. A wireless communication device is in electrical communication with the output of the power regulator and is configured to be powered by the charging power.