Damper actuator for cars with emergency function

The circuit describes a motor drive (1) for driving of flaps in the front grille of an automobile for controlling the air supply to the engine compartment. For driving the flaps, the drive comprises an electric motor (2). The emergency function provides that the electric motor (2) in the absence of the operating voltage (VB) is moved to the emergency position. For this purpose, the drive (1) on an energy store (6). This is charged during normal operation via a constant current source (8). In case of failure of the electric motor (2) and its drive circuit (5) are supplied via an up converter (9) from the energy store (6).