Abstract: A method and a control device for a brushless DC motor, which has an AC/DC inverter supplied by an intermediate direct voltage circuit for feeding the DC motor, a pattern generator for controlling switches of the AC/DC inverter having a variable frequency and phase periodical switch signal pattern and an input for a signal representative of the present phase position of the rotor of the DC motor. The pattern generator detects an average current strength released by the AC/DC inverter and adjusts a phase offset between the phase position of the rotor and the switch signal pattern in accordance with the detected average current strength and the speed of the motor.

Abstract: Device for determining the position of the rotor in an electric motor comprises a detector, which is mounted on the electric motor and which is sensitive to the passage of the rotor through a reference position, and comprises a phase-locking loop, which can be synchronized with the output signal of the detector and which furnishes an output signal representative of the position of the rotor. The moments when the rotor passes through a reference position are detected, the period of the oscillator is adapted in such a manner that the reference position passages occur at a predetermined phase of the oscillator, and the position of the rotor is derived from the oscillation of the oscillator between the reference position passages.

Abstract: A three-phase direct-current motor is controlled by cyclically repeating three first switching states. In each of the three first switching states, one of the three phases of the direct-current motor is periodically switched over between a first and a second input voltage, whereas the two other phases are continuously connected to the first input voltage.

Abstract: Device for determining the position of the rotor in an electric motor comprises a detector, which is mounted on the electric motor and which is sensitive to the passage of the rotor through a reference position, and comprises a phase-locking loop, which can be synchronized with the output signal of the detector and which furnishes an output signal representative of the position of the rotor. The moments when the rotor passes through a reference position are detected, the period of the oscillator is adapted in such a manner that the reference position passages occur at a predetermined phase of the oscillator, and the position of the rotor is derived from the oscillation of the oscillator between the reference position passages.

Abstract: A method and a control device for a brushless DC motor, which has an AC/DC inverter supplied by an intermediate direct voltage circuit for feeding the DC motor, a pattern generator for controlling switches of the AC/DC inverter having a variable frequency and phase periodical switch signal pattern and an input for a signal representative of the present phase position of the rotor of the DC motor. The pattern generator detects an average current strength released by the AC/DC inverter and adjusts a phase offset between the phase position of the rotor and the switch signal pattern in accordance with the detected average current strength and the speed of the motor.

Abstract: A three-phase direct-current motor is controlled by cyclically repeating three first switching states. In each of the three first switching states, one of the three phases of the direct-current motor is periodically switched over between a first and a second input voltage, whereas the two other phases are continuously connected to the first input voltage.