A cutting element for the machining of metallic workpieces has a body formed with an upper and a lower face of which at least one is designed as a mounting face, and a side face that connects the upper and the lower faces, that is perpendicular thereto, and that together with the upper and lower faces forms cutting edges usable for machining. Inputting and outputting pins 5 for electrically connecting the image pick-up element to a control circuit board 13 for controlling the image pick-up element are provided in a direction that does not interfere with the contact part of the element mounting part 7 and a heat absorbing mechanism 8. The second differential pair is coupled to one of the first differential pair, such that a large output voltage swing is distributed to all transistors to avoid breakdowns thereof. The adapter features clamps for gripping the inner surface of a wall cavity or sleeve and a rectangular plate for mounting an faceplate designed for junction box mounting. The terminating of the ends is reversed at about voltage zero-crossings in the power line to clear a fault.