A resistance welding apparatus for the resistance welding of at least one component, comprising:
- a welding tool comprising a first welding electrode and a second welding electrode each configured to contact the at least one component and to receive a polarity-switchable electric welding current for welding the at least one component;
- at least one welding transformer configured to output at least one secondary voltage;
- a rectifier circuit operably connected to the at least one welding transformer and the welding tool, the rectifier circuit including a first transistor and a second transistor connected in series between the first welding electrode and a secondary winding of the at least one welding transformer to receive the at least one secondary voltage, the rectifier circuit configured to output the polarity-switchable electric welding current to the welding tool during the welding of the at least one component;
- a control device configured to control a polarity of the at least one welding transformer by transmitting polarity information directly to the at least one welding transformer through at least one first line connecting the control device to a primary winding of the at least one welding transformer;
- and
- a polarity switching device of the at least one welding transformer operably connected to the first transistor and the second transistor of the rectifier circuit, the polarity switching device configured to receive the polarity information that is applied to the at least one welding transformer through the at least one first line,
- wherein the polarity switching device is configured to switch a polarity of the at least one welding transformer based on the polarity information by driving the first transistor and the second transistor to output the polarity-switchable electric welding current from the rectifier circuit,
- wherein a polarity of the first transistor is opposite a polarity of the second transistor in the series connection of the first transistor and the second transistor, such that a polarity of a welding voltage at the first welding electrode is switchable with the switching of the polarity of the at least one welding transformer as performed by the polarity switching device, and such that a polarity of the polarity-switchable electric welding current is switchable with the switching of the polarity of the at least one welding transformer as performed by the polarity switching device, and
- wherein the polarity information is a polarity of an AC voltage carried by the at least one line that is applied to the primary winding of the at least one welding transformer for the generation of the polarity-switchable electric welding current and the welding voltage.