The present disclosure generally describes techniques for separating semiconducting carbon nanotubes from metallic carbon nanotubes in a carbon nanotube dispersion. The permeable belt including a first side being guided over a portion of the exterior surface of the roll. As an initial step of the routine, it is determined whether such a ground condition exists. The balancing winding set winds around the core and includes a first balancing coil and a second balancing coil which wind around the core in a combinative way. The method includes applying the charging power to the wireless power receiver; determining whether a current value of the charging power is greater than a predetermined threshold; and driving the overcurrent protection circuit upon a determination that the current value of the charging power is greater than the predetermined threshold. In an example, a mounting device is disclosed which includes a housing adapted to be mounted to the barrel such that the housing is fixed against rotation relative to the barrel.