Verfahren und Vorrichtung zur Einschaltstromstoss-Vermeidung.

A device for preventing rush-in current when an inductance power supply unit (2) is switched on, has an alternating current switch (9) connected in series with (2) and a phase control circuit (19), which adjusts the connection between the power supply unit and the mains AC (3, 4) from the moment of power-up (7) with unipolar phase sections of equal size. Moreover, a switching device (12) is provided to control the phase control circuit (19) and it is capable of generating a predetermined number of unipolar sections of the same size. The next chronological opposite-pole half-wave is switched from 170 to 180 degrees by means of an ignition signal. In the phase control circuit (19), an ignition signal is generated at the predetermined phase control angle in the half-wave following the first half-wave. Thus, independent of the remanence in the power supply unit existing as a result of a previous switch-off, low-voltage illumination systems can be reliably dimmed up or a welding transformer can be switched on using simple means and with few electronic devices without the occurrence of a peak rush-in current.