After the first predetermined waiting time, at a time T5 the voltage 205 is again reduced to the second value 215. At a time T6, following a further predetermined waiting interval there is a further reduction to the third value 220.
At a time T7 both loads are switched off by disconnecting them from at least one of the terminals 120, 125 of the device 100, in particular by means of an associated switch 130. The currents flowing through the loads 105 fall at first rapidly and then more slowly to zero. The same effect can be produced by reducing the voltage 205 to the fourth value 225.