摘要:
A circuit and a method for operation of a gas discharge lamp includes a switching transformer having a switch, a converter, inductor and a controller in a control loop for measuring a lamp voltage and setting a desired power. The switching transformer further includes a second control loop used for adjusting the switching transformer to individual lamp conditions.
摘要:
The invention relates to a method for operating a discharge lamp 11 including two electrodes 12,13. The method comprises applying to the electrodes an alternating current ILamp. In order to improve the performance of the lamp and to increase the life time of the lamp, it is proposed that the alternating current has a direct current component DC for compensating a temperature difference between the two electrodes. The direct current component is selected more specifically such that a first electrode, which is expected to have a lower temperature than the second electrode, functions as anode for the direct current component, while the second electrode functions as cathode for the direct current component. The invention relates equally to an electronic circuit and to a software program for operating a discharge lamp correspondingly, as well as to a lighting system comprising a discharge lamp and means for operating this discharge lamp correspondingly.
摘要:
The invention describes a method of transmitting information between an information transmitter and an information receiver, the potential difference of which moves in cycles between a minimum value and a maximum value and is situated at the minimum value for regular intervals; having the steps: provision of information over the time interval or determining the time interval in which the potential difference between information transmitter and information receiver assumes its minimum value; closing of a switching means of the information transmitter in relation to an information memory assigned to the information receiver, only within the time interval; and transmission and storage of the information in the information memory.
摘要:
A projection system for image reproduction includes at least one lamp and sensor for generating a sensor signal for monitoring changes in the luminous flux generated by the lamp and for compensating these changes through a suitable control of the image reproduction. The projection system further includes a device for eliminating substantially periodic interference components from the sensor signal generated by the sensor. These interference components may be generated by an optical component such as a color modulator of the projection system. The projection system provides substantially interference-free compensation of fluctuations in the luminous flux generated by the lamp, for example, owing to an unstable arc discharge. Further, the positioning of the sensor in the projection system may not be critical.
摘要:
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. This resetting must occur so soon after the arc jump, and the conversion so slowly, that the changes in the brightness of the light incident on a picture screen device (118) resulting from the arc jump, the reset, and the conversion are not perceptible to the human eye.
摘要:
A circuit includes a converter for converting an a.c. voltage into a d.c. voltage. The converter has a diode half-bridge, a switch half-bridge, and two d.c. rails. Further, the converter has a second converter for converting the a.c. voltage into a second d.c. voltage.
摘要:
The invention relates to a DC/DC converter for use in a decentralized power generation system. If a DC/DC converter is physically separated from a power receiving component and connected to such a power receiving component via a DC bus, a short-circuit on the DC bus may endanger the system and service personnel. In order to minimize such a risk, it is proposed that the DC/DC converter comprises a converting component for DC/DC converting a direct current supplied by a power generating unit and for supplying a resulting converted direct current to a DC bus, and that the DC/DC converter comprises in addition a control component arranged to monitor a voltage at the outputs of the DC/DC converter and to cause the converting component to enter a short-circuit protection mode if the monitored voltage lies below a predetermined voltage threshold. The invention relates equally to a corresponding system and to a corresponding method.
摘要:
A lighting device for generating colored and white light. According to the invention the lighting device comprises at least one light source (1, 4) emitting blue or ultraviolet light and a color conversion unit (2, 5) for converting said blue or ultraviolet light into visible light comprising at least two sections (2a, 2b, 2c, 6a, 6b, 6c, 6d), at least one section (2c, 6d) of which being a transparent or translucent color converting section, said color conversion unit (2, 5) being arranged for alternately illuminating said at least two sections (2a, 2b, 2c, 6a, 6b, 6c, 6d) with said blue or ultraviolet light, said at least one color converting section containing luminescent material, wherein said luminescent material is a luminescent organic dye in a polymer matrix or a crystalline inorganic luminescent material.
摘要:
A method of determining a zero point of a current sensor in a circuit arrangement for operating a gas discharge lamp includes switching off the current through the sensor for a short period during a first half wave and determining a first test value. Then the current through the sensor is switched off for a short period during a second half wave having a different polarity and a second test value is determined. The average value of the two test values is formed and the zero point is determined using the average value. It is prevented thereby that the zero point drifts during lamp operation, and that amplitudes of the positive and negative half waves of the lamp current are formed differently.
摘要:
Current switching point determination devices use two comparators with fixed threshold values. According to an exemplary embodiment of the present invention, a power inverter control device for switching point determination is provided which comprises a filter circuit and a subsequent single comparator. By this arrangement, the time event is independent of the amplitude and for sufficiently small frequencies also of the frequency.