Abstract: An electric welding apparatus which, for controlling at least one welding parameter, such as welding voltage or welding current, comprises a switching mode power supply (SMPS) as control element, the switching mode power supply preferably being regulated on the primary. The actual values of voltage and current are taken from the output of the switching mode power supply and fed to an analog control circuit. The set values of voltage and current are fed to a microprocessor via an entry keyboard, and in the microprocessor they are stored in a memory and passed on in analogous form to the analog control circuit which carries out a comparison of set value and actual value and, in dependence thereon, produces an error signal that is fed to a pulse width modulator of the switching mode power supply.

Abstract: An electronic welding apparatus which, for controlling at least one welding parameter, such as welding voltage or welding current, comprises a switching mode power supply as a control element and preferably being regulated on the primary. The actual values of voltage and current are taken from the output of the switching mode power supply and fed to an analog control circuit. The set values of voltage and current are fed via an entry keyboard to a microprocessor where they are stored in a memory and passed on in analogous form to the analog control circuit which carries out a comparison of set value and actual value and, in dependence thereon, produces an error signal that is fed to a pulse width modultor which is connected to the driver stages of the power supply's switching stages which are designed as a boost regulator or a buck regulator, and thus a pulse width modulation of the current pulses of the switching stages is effected in dependence on the difference between actual and nominal values.