Actuation device for motor vehicle parts which are movable by an

Abstract

An actuation device for motor vehicle parts that are movable by an electric motor, in particular for window regulators and sliding roofs that are driven by a reversible electric motor. This actuation device has a setpoint value device for the desired position of the movable part, an incremental actual-value device for producing a signal corresponding to the actual position of the movable part, an absolute actual value device which emits first and second signals that are positionally fixed relative to the incremental actual-value device, and a microprocessor to compare the setpoint and actual value signals and to perform control and regulation programs. The signal emitted by the absolute actual-value device changes only at predetermined position values and the absolute actual-value device has position zones which are separated from one another by these position values that can be predetermined. The first and last position zones are each defined by a first or second end position of the movable part. The absolute actual-value device has at least five separate position zones and emits the first signal in the first and last position zone, and the first and last position zone are wider than all other position zones in which the absolute actual value device emits the first signal.