Abstract: A method and a control device operate a three-phase brushless direct current motor with phase windings that are fed by an inverter connected to a voltage source having a high potential and a low potential. The semiconductor switches of the inverter are arranged in a bridge circuit and are controlled such that current always flows through two phase windings during motor operation. The motor is operated with normal commutation when the rotational speed is greater than or equal to a minimum rotational speed, wherein the angles are shifted by 60°. During start-up operation, up to the minimum rotational speed, a high-potential-side commutation angle of a phase winding is shifted toward a low-potential-side commutation angle of the phase winding by an angle greater than 0° and less than or equal to 60° with respect to the normal commutation.

Abstract: An apparatus for accommodating and making electrical contact with a luminous means, which contains a glass vessel, a luminous means base and contact pins for supplying power, in a spotlight, which contains a luminous means holder for accommodating the luminous means base with plug-type sockets for accommodating the contact pins of the luminous means, is provided. The luminous means holder has a device for monitoring the connection between the luminous means base and the luminous means holder. The monitoring device comprises a device for detecting the relative position of at least one part of the luminous means base in relation to the luminous means holder when the luminous means base is inserted into the luminous holder.

Abstract: An apparatus for accommodating and making electrical contact with a luminous means, which contains a glass vessel, a luminous means base and contact pins for supplying power, in a spotlight, which contains a luminous means holder for accommodating the luminous means base with plug-type sockets for accommodating the contact pins of the luminous means, is provided. The luminous means holder has a device for monitoring the connection between the luminous means base and the luminous means holder. The monitoring device comprises a device for detecting the relative position of at least one part of the luminous means base in relation to the luminous means holder when the luminous means base is inserted into the luminous holder.

Abstract: Disclosed is a circuit arrangement (200) for protecting a switching element (T20) from overload when activated, the switching element is connected between an electrical consumer (L1) and a supply voltage (UV) and controlled by a control signal (ST20, ST20?). The circuit arrangement has evaluation elements (60) for determining a malfunction from a switching element voltage (U20) that falls across the activated switching element (T20), a memory (80) for storing malfunction information and for generating a malfunction signal (FS20), in addition to a feedback element (90) for taking into consideration the malfunction signal (FS20) during the control of the switching element (T20) by the control signal (ST20?). The memory (80) and the feedback element (90) are configured with a reference to ground.

Abstract: According to the invention, in a method for determining the angular position of a rotor, a reference voltage is set in a calibration phase, such that when the rotor, rotating at a calibration speed, passes through a particular detection position, said voltage is the same as the electromotive force induced in the one winding coil. In a subsequent measuring phase the reference voltage is updated to a value (UR) which is equal to the product of the voltage value set in the calibration phase and the ratio of the instantaneous motor rotational speed to the calibration rotational speed. The angular position of the rotor (?1) at which the electromotive force corresponds to the updated reference voltage is thus identified as the detection position.

Abstract: The invention relates to a projector, particularly a stage projector, studio projector, film projector, and/or television projector, comprising a light source and a projector housing that surrounds the light source and is provided with a translucent covering element. At least one wall of the inventive projector housing comprises a ventilation shaft with separate ventilation ducts.

Abstract: According to the invention, in a method for determining the angular position of a rotor, a reference voltage is set in a calibration phase, such that when the rotor, rotating at a calibration speed, passes through a particular detection position, said voltage is the same as the electromotive force induced in the one winding coil. In a subsequent measuring phase the reference voltage is updated to a value (UR) which is equal to the product of the voltage value set in the calibration phase and the ratio of the instantaneous motor rotational speed to the calibration rotational speed. The angular position of the rotor (?1) at which the electromotive force corresponds to the updated reference voltage is thus identified as the detection position.