Vermes
Advanced Member level 4
This project is a result of an idea to make a starting rectifier powered by 3 phases. Transformer power is about 2kVA. The secondary winding on separate carcasses, 10mm2 cross-section. The voltage is ideal for welding. Starter was winded with a rope 16mm2 on the primary winding, insulated with cotton tape. The rectifier consists of six twisted chips 300A twisted by a copper bus bar (better heat dissipation is not necessary). The primary winding had four taps, so a corresponding “long” switch ŁK15 had to be used. Switching start/welding is done by ŁK63, which shorts the stars of the respective windings. Regulation of load/start voltage 12,3-14V, welding 43-52V (electrode 3,25 without any problem). To ensure the air flow, two 80mm ventilators were used, powered from a separate 12V winding.
Link to original thread (useful attachment) – Prostownik rozruchowy z funkcją spawania