VORRICHTUNG ZUR WECHSELSTROM-EINSCHALTBEGRENZUNG

A device for the AC switch-on limitation of an inductive power supply unit (1) features a set of primary electrical AC power switches (23, 45) connected in series and a phase control circuit which enables the connection between the primary winding (4) and the AC power supply (25, 26) which is delayed after the instant of switch-on. The control electrode (44, 45) of the initial electrical AC power switch (23) of the phase control circuit with power supply backup (30) is connected to the output of a control circuit which enables a synchronized igniting voltage to be generated when the power supply unit (1) is switched on from a preset (60, 61) phase angle of between 90 and 0 degrees before a zero crossing (115) of the AC power supply (2, 25, 26). The igniting voltage can be suppressed in order to switch off the power supply unit (1) prior to reaching a zero crossing (115) of the AC power supply (2, 25, 26). A capacitor (86) connected in parallel with the power supply unit (1) enables the remanence to be set before switch-on and after switch-off so that the power supply unit (1) can be switched on under any conditions without the risk of an inrush peak current in excess of the load current.