The disclosed embodiments relate to an asynchronous down counter, which can be loaded with any value N and then decrement exactly N times. The valve slide is of annular configuration and is arranged on piston rods mounted displaceably in the pump housing. A uniform and non-aggregation CIGS precursor layer is fabricated with the formation of nanoparticle and nanowire networks utilizing ultrasonic spaying technique. The second support plate increases the distance between an LED chip and a light exit surface thereby allowing the front support plate thickness to be reduced by about the thickness of the second support plate.