Abstract: A rotating beater brush contained within a detachable rug cleaning nozzle of a domestic vacuum cleaner carries a rare earth magnet radially spaced from the axis of rotation of the beater brush. Mounted on an interior wall of the nozzle in juxtaposed relationship to the path of the revolving magnet is an iron core coil whose turns are cut by flux derived from the magnet as it moves past the coil, the coil generating an alternating current voltage. A light-emitting diode visible to the user through an aperture in a top wall or ceiling of the nozzle is directly powered by the alternating current voltage provided by the coil wherein the diode illuminates to indicate to the user that the beater brush housed within the nozzle is rotating and has not become jammed or otherwise disabled.