The invention relates to a safety controller for an actuating drive (2.1, 2.2, 2.3) for controlling a gas flow or a liquid flow in an open-loop or closed-loop manner by means of a flap (3.1, 3.2, 3.3) or a valve, in particular in the field of heating, ventilation, and air conditioning (HVAC) systems, fire-protection systems, and/or room protection systems. A safety circuit (9.1, 9.2, 9.3) is implemented to ensure the energy supply in a safety operating mode if an electricity supply circuit (8.1, 8.2, 8.3) drops off or is lost. A control value output circuit (1.1, 1.2, 1.3) detects status signals, in particular signals of a sensor (11.1, 11.2, 11.3), and/or status parameters of a system and/or a specifiable setting of an adjustment device that can be actuated manually. The safety control value is set to one of at least two different control values (SW1, SW2, . . . ) depending on the status signals so that the safety position of the flap is determined adaptively.