Abstract: A system and method for redundantly monitoring faultless functioning of first and second rotational speed sensors on an electric motor, where the rotational speed is to precisely determine and monitor a rotor position, where a first product is formed from a first current count of the first output signal of the first sensor and a maximum count of the second output signal, a second product is formed from a second current count of the second output signal of the second sensor and a maximum count of the first output signal, the two products are cyclically checked for equality and, in when the check is negative, an error message is generated, where the method provides the position of both sensors in a common values system and the positions can be directly compared with one another such that precise determination and monitoring of the rotor position becomes possible.

Abstract: An electrically commuted reversible synchronous motor is activated in a calibration journey using an externally forced rotating field, during which an electrical angle of a rotating field and a mechanical angle of the rotor are measured simultaneously at a reference position by an external sensor. These items are stored associated with one another as a measurement series of value pairs. The electrical angle of the rotating field and the mechanical angle of the rotor are also detected simultaneously after direction reversal of the rotating field. These are stored as a second measurement series of value pairs. The angle difference between the electrical angle and the mechanical angle are calculated from value pairs of both measurement series. The correction value for taking the actual incorrect angle into consideration is calculated from the two angle differences by averaging.

Abstract: An aspect of the invention is a method and a device for controlling a rotating field machine having several phase windings, which can be controlled by means of pulse width modulation, wherein a pulse width modulation controller is adapted in such a way that an individual winding of the phase windings of the rotating field machine is energized at a specifiable sampling time.

Abstract: A method ascertains a correction value for the angle of the rotor of an electrically commuted reversible synchronous motor relative to a sensor used for the activation thereof. In order to equalize the sensor and recognize and correct electrical incorrect angles and incorrect controls, the motor is activated in a calibration journey using an externally forced rotating field. The electrical angle of the rotating field and the mechanical angle of the rotor are measured simultaneously by the external sensor on at least one reference position during the calibration journey and stored associated with one another as a measurement series of value pairs. The electrical angle of the rotating field and the mechanical angle of the rotor, which is measured by the sensor, are also detected simultaneously after direction reversal of the rotating field. These are stored associated with one another as a second measurement series of value pairs.

Abstract: There is described a method and an apparatus for pulse width modulation with a predefined switching period having an adjustable ratio of the switch-on duration to the switch-off duration, in which a quantized signal is converted into a pulse-width-modulated signal and is generated in the form of a discrete pulse sequence of switch-on operations and switch-off operations with the predefined switching period, the switching edge for the switch-on duration and/or the switch-off duration being determined on the basis of the ratio of the switch-on duration to the switch-off duration.

Abstract: An aspect of the invention is a method and a device for controlling a rotating field machine having several phase windings, which can be controlled by means of pulse width modulation, wherein a pulse width modulation controller is adapted in such a way that an individual winding of the phase windings of the rotating field machine is energized at a specifiable sampling time.

Abstract: There is described a method and an apparatus for pulse width modulation with a predefined switching period having an adjustable ratio of the switch-on duration to the switch-off duration, in which a quantized signal is converted into a pulse-width-modulated signal and is generated in the form of a discrete pulse sequence of switch-on operations and switch-off operations with the predefined switching period, the switching edge for the switch-on duration and/or the switch-off duration being determined on the basis of the ratio of the switch-on duration to the switch-off duration.

Abstract: The invention relates to a door drive for an automatic door having a door panel, a brushless electric motor for generating the drive power and a belt or chain running in the opening and closing direction of the door for transmitting the drive power to the door panel. The door position is affected by a door position controller. An actuation device for controlling and/or regulating the electric motor includes an angle sensor for generating an angular signal proportional to the angle of rotation of the motor and a commutation circuit, for electronically commutating the motor, where the angular signal from the angle sensor is fed. The angular signal is also used as an input variable to the door position controller. The angle sensor is, in particular, an absolute value angle sensor working on a magnetic principle and designed for the unambiguous sensing of one complete revolution of the electric motor.

Abstract: A door operating mechanism for an automatic door is described, in particular for an automatic sliding and/or elevator door. A driving pinion or belt pulley for driving a belt or a chain which is used for transmitting the driving force generated by a motor to the door leaf is mounted to the shaft of the motor. The motor can be aligned with its shaft perpendicular to the opening and closing direction of the door. The door operating mechanism is of particularly compact design, even more so if the motor is an electronically commutated brushless synchronous motor and a magnetic angular encoder embodied as an absolute encoder and resolving 360° is used.