Abstract: An arc trainer for welders comprises a welding electrode simulator, a welding object simulating unit, a welding power source whose outputs are connected to the electrode simulator and to the welding object simulation unit, a unit controlling the quality of the simulated welding process and generation of feedback signals for the trainee, which is connected to the welding electrode simulator and to the welding power source, a unit monitoring variations of welding parameters, which is connected to the control unit and to the welding power source, and a helmet connected to the control unit.