A microcontroller with a self-prompting (self-wake-up) device, particularly for use in electrical adjusting drives, having a control device for specifying an active and an inactive operating state to economize on supply power, contains an oscillator for emitting a prompting signal or a clock frequency. This oscillator is a low-frequency, power-saving oscillator. Provided in the microcontroller is a circuit, preferably a disconnectible phase-locking loop, which, from the low frequency of the oscillator, generates a substantially higher clock frequency for microcontroller core. The low-frequency oscillator is also integrated as an original component into the microcontroller. An undervoltage detection, whose output signal is able to be supplied directly to the microcontroller core, indicates undervoltage conditions immediately. Using a time-switch logic which monitors a non-operative time of the microcontroller core, the core is activated again via a prompting circuit. In the case of certain functions, it is also possible to work in a power-saving manner solely with the low frequency. Thus, a necessary buffer capacitance can be smaller.

In a displacement drive that provides an obstruction prevention function for movable parts, in particular such as windows and sunroofs in motor vehicles, a decrease in the rotation speed or velocity of the drive is provided in order to achieve a predefined spring rate in specific displacement ranges so as to lower the kinetic energy. Within the predefined range before the closed position is reached, the rotation speed and/or the output of the drive is reduced linearly. The reduction to a minimum rotation speed or minimum output takes place within a specific position range. The minimum rotation speed or minimum output is reached at a specific position before the closed position and is substantially constant. Corresponding to different supply output levels, a linear reduction, for example, is performed along lines of different slopes, the length of the specific position range in which the reduction is performed being constant.

An arrangement for the determination of the temperature of a direct-current motor. The temperature is determined in an indirect manner from the temperature-dependent armature resistance, with the armature resistance being determined as the quotient of the voltage being applied to and measured at the motor terminals and of the blocking current of the armature, and being set in relation to the respective temperature. The current signal determined from the current flowing within the armature is averaged with adjustable, calculated integration times with the aid of an integrator that can be controlled by a microcontroller. The arrangement, can be used for the indirect determination of the rpm rate (N) and/or variations that are critical or of interest in the rpm rate of the motor. The rpm rate is proportional to the voltage (U.sub.ind) induced within the armature, taking into consideration a motor-typical proportionality constant (.kappa.) according to equation N=.kappa. U.sub.ind, with the voltage induced within the armature being determined as the difference between the voltage being applied to the motor terminals and the product of armature current and armature resistance.

The invention relates to a tracking detection system of electrical servomotors with incremental position detection in particular for servomotors in motor vehicles. To determine the position, said tracking detection system is provided with a microcontroller with an autoalarm device. Said microcontroller can be moved from run mode (B1) to sleep mode (B0) to reduce the average current intake, and after a predetermined period of time (e.g. 1 mm) can be automatically moved back to run mode (B1). Said microcontroller samples the position signals (HS) of position transmitter when it is in run mode (B1) at particular sampling points (11, 12), and is move between the required sampling points for a particular, calculated period of time in sleep mode (B0). The particular, calculated period of time is calculated from a detected edge change of the position signal.

An electric motor drive having a first section and a second section offset with respect to the first section. A control arrangement and an evaluation arrangement are arranged in the first section, and an electric motor and a sensor arrangement are arranged in the second section. The control arrangement is connected to the electric motor via two connecting lines. A signal is transmitted from the sensor arrangement to the evaluation arrangement via a third line. The electric energy for the sensor arrangement is transmitted via at least one of the two connecting lines and via the third line, or only via the two lines. The electric motor drive according to the invention is suitable for use in actuators which may be arranged in a motor vehicle.