The invention is related to methods and apparatus that conceal errors in images of a corrupted video bitstream. The driver and the converter are adapted to fit inside the foundation elements. Atmospheres respectively in contact with the anode and cathode layers are operated according a method in which they are isolated from each other. Various contact tip assemblies and manufacturing techniques for forming contact tips are also provided. The reservoir module may receive a lubricant and provide lubricant to a differential bearing. In an embodiment, a sensor element comprises a non-elongated xMR structure; and a plurality of contact regions formed on the xMR structure spaced apart from one another such that a non-homogeneous current direction and current density distribution are induced in the xMR structure when a voltage is applied between the plurality of contact regions.