Abstract: The invention relates to an electronic circuit and a method of supplying energy to a high-pressure gas-discharge lamp H, 65, 75. The electronic circuit comprises a line-supply input section 62, 72 to receive and convert an a.c. voltage from an a.c. line-supply system 61, 71, an energy storage means 63, 73 to store the energy put out by the line-supply input section 62, 72 and a lamp-current regulating unit 64, 74 that is supplied with an input voltage U1 by the line-supply input section 62, 72 via the energy storage means 63, 73 and that makes available a lamp current I2 for a high-pressure gas-discharge lamp II, 65, 75. To make it possible for the energy storage means 63, 73 to be particularly small, it is proposed that the lamp-current regulating unit 64, 74 have a power section L, D, C, S, A1, A2, K having a transconductive property.

Abstract: The invention relates to an image projector with a High-Intensity-Discharge HID lamp (112) and a method of operating it. Such lamps have the disadvantage that their voltaic arc jumps back and forth between different positions at unforeseeable times during operation. This so-called arc jumping has the effect of changing the brightness, i.e. the overall brightness and/or the brightness distribution of the light emitted by the HID lamp (112). For the viewer of an image projected with such a projector, this effect appears as a jolt of this projected image. To avoid such effects for the viewer, it is first proposed according to the invention that changes in the brightness of the light in the image projector's beam path are detected. As soon as a change in brightness caused by an arc jump has been detected, this brightness is reset to a brightness detected at a moment t-2 before the arc jump, in order subsequently to convert it during a predetermined time interval T to the brightness resulting from the arc jump.

Abstract: The invention relates to a device for generating an image for projection, the device comprising a light source, a light source drive unit, electro-optical light modulation means including color scanning means for simultaneously generating scrolling image parts of different colors, image projection means for projecting the image by using said scrolling image parts and a projection drive unit for controlling said image projection means by a control signal including the image data to be projected. In such devices, a UHP lamp is often used as a light source. Therein, a pulse on the lamp current is used to shape the electrodes in such a way that the lamp arc remains in a stable position.

Abstract: The invention relates to a ballast arrangement for igniting and operating a discharge lamp. The lamp is connected in a commutating bridge in series with an inductor and parallel to a capacitor. The conductor and the capacitor together form a resonance circuit. During ignition, the bridge is commutated at a comparatively high frequency that changes with respect to time. According to the invention, the series resonance circuit has a resonance frequency that is close to an odd harmonic of the comparatively high frequency.

Abstract: An electronic circuit for operating a High Intensity Discharge (HID) lamp, in particular a Ultra High Pressure (UHP) lamp, such as those preferably used in image projectors. The circuit comprises a lamp ballast for offering a controlled lamp current for operating the HID lamp and a brightness sensor for generating and providing a sensor signal which represents the brightness of the light applied by the lamp to the image generator. The lamp ballast controls the lamp current such that the brightness of the light of the lamp remains constant. Brightness control is made possible throughout the entire operational life of the lamp, and the use of sensors of simple construction is made possible by an incorporation within the electric circuit of a filter that high-pass filters the sensor signal before it is supplied as a control signal to the lamp ballast.

Abstract: The invention concerns an electronic component, the application of a component of this kind and a method for manufacturing a component of this kind with capacitive characteristics. In order to integrate an electrolytic capacitor into integrated circuits, it is suggested that a polymer electrolytic capacitor be of laminated, planar execution. It thereby becomes possible to integrate an electrolytic capacitor into a printed circuit board, as a result of which the overall height, the production capability and the electromagnetic compatibility of a circuit of this kind are improved.

Abstract: The invention concerns an electronic component, the application of a component of this kind and a method for manufacturing a component of this kind with capacitive characteristics. In order to integrate an electrolytic capacitor into integrated circuits, it is suggested that a polymer electrolytic capacitor be of laminated, planar execution. It thereby becomes possible to integrate an electrolytic capacitor into a printed circuit board, as a result of which the overall height, the production capability and the electromagnetic compatibility of a circuit of this kind are improved.

Abstract: The invention relates to an electronic circuit for operating a High Intensity Discharge (HID) lamp, in particular a Ultra High Pressure (UHP) lamp, such as those preferably used in image projectors. The circuit comprises a lamp ballast 110 for offering a controlled lamp current for operating the HID lamp 422 and a brightness sensor 130 for generating and providing a sensor signal which represents the brightness of the light applied by the lamp to the image generator. The lamp ballast 110 controls the lamp current such that the brightness of the light of the lamp remains constant. It is an object of the invention to develop the electronic circuit and the image projector further such that the brightness control is made possible throughout the entire operational life of the lamp 322, and the use of sensors of simple construction, and thus less expensive sensors, is made possible.

Abstract: The invention relates to a standby circuit, an electrical device with a standby circuit, a method for the control of the electrical device and a power supply assembly. Whereas the power supply unit and the control electronics are in permanent operation when conventional devices are in the standby mode and consequently have a high power consumption, the invention proposes a solution for saving energy while retaining convenience of operation by which the power supply unit is switched off in the standby mode. A standby circuit, preferably fed by an energy buffer element, remains active in the standby mode and monitors signal inputs for activation events. When an activation event occurs, the standby circuit switches on the power supply unit.

Abstract: A drive system including a rectifier, a high-frequency filter, a static inverter and an induction motor is driven without energy stores and fed by the single-phase mains, in which the use of an envelope generator with a mains-synchronous, preferably sinusoidal signal causes a preferably sinusoidal envelope to be sign-superimposed on the static inverter output signal, thus preventing inadmissible current overshoots in the single-phase mains. Possible fluctuations of the intermediate circuit voltage are thereby compensated. The advantageous operating frequency of the static inverter may be adjusted automatically by a PLL control circuit in that the phase shift between intermediate current and the envelope signal is evaluated. The advantageous operating frequency may be gained by adding a given frequency difference to the rotational speed of the motor. The envelope directly represents a projection of the variation of the voltage of the single-phase mains.

Abstract: The present invention relates to a control element having a rotary knob (4), having a magnetic circuit and having at least one coil (1). The rotary knob (4) is supported so as to be rotatable with respect to at least a part of the magnetic circuit, the gap (5) present between the rotary knob (4) and the magnetic circuit is filled with a magnetorheologic fluid, and the coil (1) is arranged to exert a variable braking action on the rotary knob (4).

Abstract: The invention relates to a power supply unit or battery charging device (1). While of compact type, the device is to dissipate to the environment the heat generated during operation and, on the other hand, is to be extremely handy. There is proposed to provide cooling fins (4) on the housing (2) of the device, while the cooling fins (2) are arranged so that the cooling fin interstices are suitable for locking a cable (5) of the device.

Abstract: The invention relates to a converter including a fly-back circuit (5). For obtaining a maximum possible adaptation to the internationally different network voltages, there is proposed to provide a first fly-back frequency range for a converter input voltage (Unet) lying in a first voltage range and a second fly-back switching frequency range for a converter input voltage (Unet) lying in a second voltage range, the first voltage range having smaller voltage values than the second voltage range and the first fly-back switching frequency range having larger frequency values than the second fly-back switching frequency range.

Abstract: A drive system comprising a rectifier, a high-frequency filter, a static inverter and an induction motor is driven without energy stores and fed by the single-phase mains, in which the use of an envelope generator with a mains-synchronous, preferably sinusoidal signal causes a preferably sinusoidal envelope to be sign-superimposed on the static inverter output signal, thus preventing inadmissible current overshoots in the single-phase mains. Possible fluctuations of the intermediate circuit voltage are thereby compensated.

Abstract: The invention relates to a power supply unit or battery charging device (1). While of compact type, the device is to dissipate to the environment the heat generated during operation and, on the other hand, is to be extremely handy. There is proposed to provide cooling fins (4) on the housing (2) of the device, while the cooling fins (2) are arranged so that the cooling fin interstices are suitable for locking a cable (5) of the device.