FIELD: electric arc welding technology; methods of control of electric arc welding processes by use of check parameter. SUBSTANCE: proposed method includes generation of control signal in real time scale for control of welding process characterized by voltage at welding and welding current at preliminary measurement of voltage and arc current during welding. Method includes spontaneous change in voltage during welding or in arc current by lesser than 10% after which voltage and welding current are measured for the second time and difference between first and second measurements is determined and derivative presenting required control signal is introduced by dividing difference between first and second measurements of voltage by difference of first and second measurements of welding current and control signal is generated by this magnitude of derivative. Device is provided with current source, welding current sensor and controller for control of voltage and/or welding current including digital circuit for primary and secondary recording of voltage during welding and welding current, control circuit for change of voltage during welding between moments of primary and secondary recording, digital circuit for determination of difference between recorded voltages and currents and derivative generating circuit for dividing difference of voltages by difference of currents for obtaining control signal. EFFECT: improved quality of welding. 23 cl, 14 dwg
