FIELD: welding operations. SUBSTANCE: proposed multistage step-down interrupter for arc welding provides for flow of current between electrode and billet. It includes input D C source, first switching-over stage with first switching-over device and first choke. This first stage selectively connects input D C source between electrode and billet and ensures controlled operational cycle and rate of switching over. Second switching-over stage of interrupter has second switching- over device and second choke. Second stage of interrupter also selectively connects mentioned above input D C source between electrode and billet with above-specified controlled operational cycle and rate of switching over. Updating of interrupter consists in positioning of first and second chokes on one core and in provision of feedback circuit with correction of minimal current. EFFECT: increased functional reliability. 24 cl, 11 dwg
