Abstract: A method and apparatus for manually controlling a windscreen wiper drive motor in a motor vehicle in several speed steps, by which the drive motor can also be automatically switched from a manually switched-on speed step into a lower speed step when the speed passes through a predetermined threshold value of the motor vehicle travelling speed from a higher travelling speed. The apparatus and method provide automatic switching of the drive motor from each manually switched-on speed step into a lower speed step when the speed passes through the threshold value, cancellation of the current automatic switching until the speed again passes through the threshold value from a higher travelling speed when the control switch has been operated below the threshold value of the travelling speed and after the drive motor has been automatically switched into a lower speed step, and switching-on of each speed step of the drive motor selected by this operation of the control switch.

Abstract: A method and device for adapting the sensitivity of a sensor system for the detection of precipitations during the control of wiping intervals of a screenwiper drive of a motor vehicle as a function of the kinetic energy of striking precipitations. A pressure-sensitive sensor of a sensor system detects striking precipitations, the detections of striking precipitations are converted into electrical output signals, and the output signals are transmitted via a transmission path to an amplifier with an amplification factor for activating a wiper-motor control circuit. The electrical properties of the transmission path are varied as a function of ambient temperature such that the responsiveness of the sensor system is increased with decreasing temperatures, so that a reliable response even to snowflakes of small mass are achieved.

Abstract: In a direction indicator and hazard warning device for motor vehicles, a time sequence control is provided, which, during hazard warning operation with a closed driving/ignition switch, allows direction indicator signals to be superimposed and, when the direction indicator signals are switched on, the hazard warning signal to be superimposed. The signal first selected is automatically generated once again after the added signal has been switched off. If, however, the driving/ignition switch is closed with the hazard warning switch and the direction indicator switch closed, the device causes the hazard warning signal to continue to be generated.