Abstract: The invention relates to a method for regulating the voltage of a transformer (1) having different winding taps (3). The problem addressed by the invention is that of providing a method with which different load flow directions can be regulated with conventional transformers (1) and voltage regulators (7) in order to ensure a safe and reliable supply of voltage. The general inventive concept consists in determining, using a method in which a quadrant system (11) is used, the phase angle of the conduction current (I) and thus the load flow direction, thereby preventing deviation from the voltage range as a result of power input that is too high, by controlling the load tap changer (4).

Abstract: The invention relates to a method for dehumidifying air and to an air dehumidifier. To this end, a filter element is provided that is filled with granular material that can be regenerated by baking out. For effecting this baking out, a heating device is provided that is only actuated when both a humidity sensor indicates that a humidity limit value has been exceeded as well as a relative pressure sensor or a comparable technical means indicates that, at the moment, no flow toward the oil expansion tank is recorded.