Abstract: The bulb of the lamp is closed at opposite ends by sealing parts (6), with in each case one cap (8) being fitted at one end, the cap having an electrical contact element (13) which is connected in an electrically conductive manner to a supply conductor (15) leading to a luminous means, the contact element being accommodated in a tubular extension (11) of the sealing part. The cap part (8) has an adjustment part (14; 24), which is directed inward with respect to the interior of the lamp and is in contact with the sleeve (11) via a bracket.

Abstract: The invention relates to a circuit arrangement for detecting a crest factor of a lamp current or a lamp operating voltage of an electric lamp (2), the circuit arrangement having a first subcircuit (15), which is designed to determine an averaged value from an input signal applied to the circuit arrangement, having a second subcircuit (16), which is designed to determine a maximum permissible value from the input signal applied to the circuit arrangement and having a comparator circuit (17), which is designed to produce a comparison signal from the output signal of the first subcircuit (15) characterizing the averaged value and from an output signal of the second subcircuit (16) characterizing the maximum permissible crest factor. The invention also relates to a method for detecting such a crest factor. One further aspect of the invention relates to an electronic ballast (1) which has a circuit arrangement (14a, 14b) according to the invention.

Abstract: Circuit arrangement having a converter without a transformer but with an inductor for the pulsed operation of dielectric barrier discharge lamps The circuit arrangement according to the invention comprises an inductor-type converter for the pulsed operation of dielectric barrier discharge lamps (EL). The invention proposes both a half bridge variant and a full bridge variant. By selecting the inductance value of the inductor (L), it is possible to influence the edge steepness of the pulses, in the case of more than one inductor even independently for the rising and falling edges.

Abstract: The invention relates to a novel ballast for a discharge lamp, in which a continuous-operation control circuit is brought out of operation when a physical operation, which defines a preheating time, of a preheating timer has as yet not been sufficiently returned if the lamp is intended to be restarted.

Abstract: The invention relates to a method for designing a discharge lamp for use with a light-gathering system, in particular of a projector for data or video projection. Also disclosed are a lamp designed using such a method and a reflector provided therefore.

Abstract: A coated luminescent material having a luminescent material powder formed by grains, the luminescent grains being coated, and the coating being at most 5 nm, preferably at most 2 nm.

Abstract: An electric lamp having a base at one end, a lamp bulb sealed in a vacuum-tight manner, the lamp bulb being surrounded by an envelope part, a base having electrical connections bearing on one side the outer bulb and on the other side the envelope part, having the following features: a) the base has a base insulator which has a central opening in which the outer bulb is accommodated without cement; b) the base insulator has a circular, radially projecting segment having an upper and lower plateau which is associated with the base; c) on the base side the envelope part has a circular opening having a radially projecting edge which has a lower and an upper contact surface in relation to the base, the lower contact surface matching the upper plateau; and d) the envelope part is fixed to the base via a cement-free, mechanical retaining mechanism.

Abstract: An adapter for providing a recessed lamp in a screw-type lampholder. This adapter has an electrical contact-making device, via which an electrical connection is produced between a screw base, which can be introduced into the screw-type lampholder, of the adapter and the recessed lamp once the recessed lamp has been introduced into the adapter. Furthermore, the adapter has a switchable electrical connecting device, via which, in the state in which there is no mechanical connection between an enveloping bulb for the recessed lamp and the adapter, an electrical connection is not produced between the screw base and the recessed lamp, and via which, in the state in which the recessed lamp is surrounded, at least in sections, by the enveloping bulb, an electrical connection is produced between the screw base and the recessed lamp. As a result, the recessed lamp in the adapter can only be operated with the enveloping bulb placed thereon.

Abstract: An illumination device, comprising a light emitting diode (11) fixed on a circuit board (12). The illumination device furthermore has an optical element (10) disposed downstream of the light emitting diode (11) in a main emission direction (15), the optical element (10) being configured for directing a first portion (6a) of the electromagnetic radiation (9) emitted by the light emitting diode (11) during operation through the circuit board (12) in a direction away from the circuit board (12).

Abstract: A ballast having a dimming device for a low-pressure discharge lamp. It has two technically different possibilities for controlling the lamp brightness. The first possibility for controlling the lamp brightness is by means of adjusting the amplitude of the lamp current. The second possibility for brightness control is based on the fact that the low-pressure discharge lamp can be operated with a pulsed lamp current. In particular, both operating modes are used in combination in specific brightness ranges.

Abstract: The metal halide lamp has a ceramic discharge vessel and contains two groups of metal halides: a first group made up of the emitters and a second group made up of the wetters. The second group comprises at least one of the metal halides of Mg or Yb.

Abstract: In the metal halide high-pressure discharge lamp for stage, film and television lighting systems and for projection technology and effect lighting, the discharge vessel contains dysprosium and cesium as fill metals for the metal halides. Optimum results for dimmability, arc instability and color rendering are achieved if the fill additionally includes 0.12 to 3.8 ?mol of vanadium and if appropriate 0.05 to 1.0 ?mol of zirconium per ml of vessel volume. These metals achieve improved color rendering, in particular red rendering, with an Ra of from 70 to 95 and an R9 of from 45 to 90.

Abstract: The present invention relates to an electronic ballast for discharge lamps, for example low-pressure discharge lamps, having a converter having a switching element and a two-part lamp inductor which is connected upstream and downstream of the discharge lamp. An electronic ballast according to the invention has a smoothing circuit which reduces voltage jumps caused by switching operations in the converter at the lamp terminals.

Abstract: A voltage converter, whose topology can be switched over between a boost converter and a SEPIC. The boost converter has ripple current compensation. As a result, the inductors used can be utilized in optimum fashion. A thyristor which is protected against breakdown triggering by a negative gate voltage is used as the changeover switch.

Abstract: An electric lamp has a discharge vessel which is sealed in a vacuum-tight manner and is made from glass, the discharge vessel being surrounded in particular by an envelope part, the discharge vessel being essentially cylindrical, and defining a longitudinal axis L, and containing two electrodes at a predetermined distance from one another as well as a filling, an electrically insulated insert part also being fitted in the discharge vessel over a central part of the axial length. The electrically insulated insert part extends at least over the distance between the electrodes EA, it is fitted in the discharge vessel without the use of a retaining device, and it surrounds the electrodes in essentially tubular fashion such that it is spaced apart from them.

Abstract: An illumination system has at least two light sources of which at least one light source includes an LED, and a driver device designed to operate at least the one LED with a DC signal; a sensor device for determining at least one feature of the light output; an actual value storage device connected to the sensor device for storing an actual value of the feature; a setpoint selection device for storing a setpoint of the feature; and a control device connected on the input side to the actual value storage device for of transmitting the actual value, and to the setpoint selection device for transmitting the setpoint, and which provides the driver device with a control signal that changes a characteristic of the DC signal used for driving the LED such that the actual value approaches the setpoint.

Abstract: A short arc high-pressure discharge lamp (1) for dc operation, includes a discharge vessel (2) that has two necks (4) diametrically opposite each other, in which an anode (26) and a cathode (7) made of tungsten are melted in a gastight manner, and which has a filling made of at least one noble gas and possibly mercury. According to the invention, at least the material of the cathode tip (11) contains lanthanum oxide La2O3 and at least another oxide from the group consisting of hafnium oxide HfO2 and zirconium oxide ZrO2 in addition to the abovementioned tungsten.

Abstract: The invention relates to a high-pressure discharge lamp having electrodes arranged inside a discharge vessel which define a discharge path of a gas discharge in the discharge vessel, and having a starting device, arranged inside the lamp base for the high-pressure discharge lamp and designed as a pulse starting device, for starting the gas discharge in the discharge vessel, and having, arranged outside its discharge vessel, an auxiliary starting electrode coupled to the pulse starting device, the voltage input of pulse starting device being connected in parallel with the discharge path of the high-pressure discharge lamp, such that according to the invention the voltage across the discharge path serves as supply voltage for the pulse starting device. Also disclosed is an operating method for such a high-pressure discharge lamp.

Abstract: An electric light bulb, in particular a halogen light bulb designed to be operated by mains voltage includes a substantially axially symmetrical bulb and a single-coil filament mounted in the bulb. The filament includes at least one incandescent coil section disposed outside the bulb axis. The incandescent coil is disposed axially in a transparent cylindrical sleeve which has an interference filter that reflects infra-red rays.

Abstract: The invention relates to a luminescence conversion led based illumination deice that emits primarily radiation in the range of from 370 and 430 nm of the optical spectrum (peak wavelength). Said radiation is converted to radiation having a longer wavelength using three luminescent substances that emit in the red, green and blue range.