Provided is an evaluation system including: an analog-to-digital converting section comprised of a programmable circuit and configured to convert an analog signal, the analog signal being acquired by a physical quantity acquiring section and indicative of a time-series change of at least one of (i) welding current, welding voltage, or load applied to pieces to be welded and (ii) a displacement, during welding, of a welding head; and an evaluating section configured to determine, based on a digital signal, whether or not the time-series change satisfies a predetermined condition, wherein configuration data for configuring the programmable circuit is arranged to be changeable by a user.

Provided is an evaluation system including: an analog-to-digital converting section comprised of a programmable circuit and configured to convert an analog signal, the analog signal being acquired by a physical quantity acquiring section and indicative of a time-series change of at least one of (i) welding current, welding voltage, or load applied to pieces to be welded and (ii) a displacement, during welding, of a welding head; and an evaluating section configured to determine, based on a digital signal, whether or not the time-series change satisfies a predetermined condition, wherein configuration data for configuring the programmable circuit is arranged to be changeable by a user.

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.

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.

The invention relates to the welding robot controller system, which will instantly check that the welding at each welding point in the resistance welding robot cells is performed according to the correct welding parameters and will instantly inform the robot and the operator in case of a nonconformity detection.