Power source for capacitor discharge welding of studs of 3 and 4 mm diameter and other accessories, with tip strike. It is suitable for applications in car body shops. It enables welding of studs on non-treated or non oxidized surfaces in steel, stainless steel, galvanized steel, brass and, in particular, aluminium. The welding process is so short that it causes no alteration to the opposing surface even if painted, plastic-coated or galvanized. Complete with gun, earth cable with clamp andaccessories.