The invention is based on the recognition that although a load which is already carrying a current, i.e. which is therefore already connected to the terminals so that a current is flowing through it, is excited to a larger current flow by the temporarily elevated voltage, its time variation is less pronounced than in the load previously carrying no current. To put it differently, a load already operated at the voltage can be operated further without damage and at the same time a higher current can be passed through a connected load in order to improve its response behavior.

It is also preferable for the method to include an adjustment of the voltage to a predetermined third value after a further predetermined time interval, this third value being lower than the second value. In particular the third value can be chosen such that in an inductive load having a solenoid with an armature, the already attracted armature is held in place. The current flowing for this is smaller than a current required to attract an armature that has moved away when the load or solenoid is not energized. Thus, in this embodiment three different voltages can be produced, that correspond to different phases of the switching on of a load which, in particular, can comprise a solenoid with an armature. The three phases can be called the boost phase (first voltage), the peak phase (second voltage) and the holding phase (third voltage).