Abstract: A data transmission method for a resistance welding current source during a welding operation generates welding pulses in an inverter with inverter switching elements cyclically with a switching frequency and pulse duration. The pulses are applied to a transformer primary side and rectified on the transformer secondary side by a rectifier with rectifier switching elements to form a resultant welding current. In a data transmission mode the impedance at the primary side is increased in the breaks in the welding operation, control pulses for initializing the data transmission mode are applied by a control device to the primary side and are detected on the secondary side. The rectifier switching elements of the secondary-side rectifier are actuated in a way corresponding to the data to be transmitted. The current on the primary side of the transformer is modulated with these data, and the data are thereby transmitted via the transformer.

Abstract: A data transmission method for a resistance welding current source during a welding operation generates welding pulses in an inverter with inverter switching elements cyclically with a switching frequency and pulse duration. The pulses are applied to a transformer primary side and rectified on the transformer secondary side by a rectifier with rectifier switching elements to form a resultant welding current. In a data transmission mode the impedance at the primary side is increased in the breaks in the welding operation, control pulses for initializing the data transmission mode are applied by a control device to the primary side and are detected on the secondary side. The rectifier switching elements of the secondary-side rectifier are actuated in a way corresponding to the data to be transmitted. The current on the primary side of the transformer is modulated with these data, and the data are thereby transmitted via the transformer.

Abstract: A power supply unit for a resistance welding apparatus, said power supply unit comprising a converter circuit adapted to convert an alternating power supply current, AC, applied via a residual current protection circuit to an input of said converter circuit into a pulsed electrical current supplied from an output of said converter circuit to a primary coil of a transformer of said resistance welding apparatus, and at least one switching element provided between the output of said converter circuit and protective earth.

Abstract: A power supply unit for a resistance welding apparatus, said power supply unit comprising a converter circuit adapted to convert an alternating power supply current, AC, applied via a residual current protection circuit to an input of said converter circuit into a pulsed electrical current supplied from an output of said converter circuit to a primary coil of a transformer of said resistance welding apparatus, and at least one switching element provided between the output of said converter circuit and protective earth.

Abstract: A monitoring module for monitoring an electric arc machining process includes a camera, a photo flash lamp and a control system that controls the photo flash lamp in such a way that it illuminates when the camera records the image. The components are arranged in a common housing. The common housing includes a compressed air connection and an air outlet (7) or a deflection device arranged at the housing, which is provided for the orientation of the discharging air beam across the optical axis of the camera. Furthermore, an air flow caused by the compressed air is led via the light source and/or the control system and/or a charging connection for the light source.

Abstract: The invention relates to a monitoring module (1 . . . 1?) for monitoring an electric arc machining process, said module comprising a camera (2), a photo flash lamp (3) and a control system (4) that controls the photo flash lamp (3) and a control system (4) that controls the photo flash lamp (3) in such a way that it illuminates when the camera (2) records the image. According to the invention, said components (2, 3, 4) are arranged in a common housing (5), which comprises a compressed air connection (6) and an air outlet (7) or a deflection device arranged at the housing (5), which is provided for the orientation of the discharging air beam perpendicular to the optical axis (A) of the camera (2). Furthermore, an air flow caused by the compressed air is led via the light source (3) and/or the control system (4) and/or a charging connection (8) for the light source (3).