MEASURING AND TESTING MACHINES AND OSCILLOSCOPE INSTRUMENTS FOR MEASURING SIZES, WEIGHTS, AND TIME, AND FOR MEASURING WAVE FORMS; POWER DISTRIBUTION AND CONTROL MACHINES AND APPARATUS, NAMELY, DC POWER SUPPLIES FOR ELECTRIC SWITCHBOARDS AND SYSTEM RACKS FOR ELECTRIC SWITCHBOARDS; TELECOMMUNICATION DEVICES AND APPARATUS, NAMELY, DC POWER SUPPLIES FOR SERVERS IN COMMUNICATION BASE STATIONS; ELECTRONIC MACHINES, APPARATUS AND SPARE PARTS, NAMELY, DC POWER SUPPLIES, HIGH VOLTAGE POWER SUPPLIES AND X-RAY MACHINES; OZONIZERS, NAMELY, DC POWER SUPPLIES FOR OZONIZERS; ELECTROLYZERS, NAMELY, DC POWER SUPPLIES FOR METAL PLATING AND ELECTROLYSIS; ELECTRIC ARC WELDING MACHINES; METAL CUTTING MACHINES; ELECTRIC WELDING APPARATUS, NAMELY, DC AND AC POWER SUPPLIES FOR WELDING MACHINES