Abstract: The invention relates to a low-pressure discharge lamp, having a tubular discharge vessel made from glass, the free ends of which are closed off in a gas tight manner, two electrode systems (3) each having a filament (7), two supply conductors (5, 6) and a bead (8) of glass, the ends of the supply conductors (5, 6) being fused into the ends of the discharge vessel which have been closed off in a gas tight manner and, in order to be held in a region between the filament (7) and the discharge vessel fused seal (2), into the bead (8), and a device for switching off the lamp at the end of its service life, comprising a paste (9) which contains a metal hydride and is fitted to the bead (8). According to the invention, the bead (8) consists of a glass material which has a resistivity of greater 108 ?cm at 350° C.

Abstract: The planar light source (1) uses the principle of RGB mixing, the radiation of UV diodes (5) arranged in a planar fashion being converted by means of phosphors (7) which emit in the red and green spectral regions. The blue component is added by blue-emitting LEDs (8) whose radiation is preferably launched as a lateral diode row (9).

Abstract: A rectifier circuit matched for power factor correction. A first diode (D1), a second diode (D2), a third diode (D3) and a fourth diode (D4) are in a bridge arrangement. A first pole (10) and a second pole (12) of the bridge arrangement are connected to a source (U) which has at least one AC voltage component. An inductance (L1) is arranged in series with the third pole (14) or the fourth pole (16) of the bridge arrangement. A capacitance (C1) is connected between the first pole (10) and the second pole (12), and two of the four diodes (D1, D2, D3, D4) are in the form of fast diodes.

Abstract: The invention relates to a ballast for a lamp having an inverter which includes at least one switch (S1; S2), and having a drive circuit (10) for alternately opening and closing the at least one switch (S1; S2) wherein the drive circuit (10) is designed to drive the at least one switch (S1; S2) alternately at at least two different frequencies (&ohgr;a, &ohgr;b). It also relates to a method for operating a ballast for a lamp having an inverter which comprises at least one switch (S1; S2), and having a drive circuit (10) for alternately opening and closing the at least one switch (S1; S2) wherein the drive circuit drives the at least one switch (S1; S2) alternately at at least two different frequencies (&ohgr;a, &ohgr;b).

Abstract: A novel operating circuit for a low-pressure gas discharge lamp 1 in the case of which a digital controller 12 is designed such that by gradually lowering the operating frequency in the ignition procedure it initiates shutdown operations of a safety shutdown device for excessive currents through a lamp inductor 10 in order thereafter to increase the operating frequency somewhat. It is possible overall in this way to achieve an ignition, for example by repeated pulsed ignition operations as far as shutdown operations, or else by a continuous ignition operation at a minimum frequency at which no shutdown operation occurs. The invention has the advantage of being insensitive to temperature fluctuations and component tolerances and, moreover, of permitting the lamp inductor 10 to have comparatively small dimensions.

Abstract: Illumination device with at least one LED as light source, the LED emitting primary radiation in the range from 380 to 420 nm, this radiation being partially or completely converted into longer-wave radiation by phosphors which are exposed to the primary radiation from the LED, the conversion taking place at least with the aid of a phosphor which emits over a broad band and originates from the class of the (Eu,Mn)-coactivated halophosphates, the cation M representing one of the metals Sr, Ca, Ba.

Abstract: An operating circuit for a discharge lamp (LP) having preheatable electrodes includes a device (C14, T11, T12, T13, G) for preheating the electrodes. The device includes a resonant circuit (C14, T11) which oscillates during preheating. During operation, the operating circuit produces an AC voltage having a frequency that is moved through a frequency range, records the response of the resonant circuit (C14, T11) by measuring an electrical variable (UC14), and identifies the resonant frequency of the resonant circuit (C14, T11) from the electrical variable (UC14), and preheats the electrodes by setting the frequency of the AC voltage to the resonant frequency.

Abstract: The invention relates to a novel operating circuit for a discharge lamp, in the case of which the lamp electrodes are preheated by driving switching transistors of an oscillator circuit such that their frequencies are detuned with reference to the resonant frequency of the lamp circuit. The drive frequency is defined by an independent resonant circuit.

Abstract: A free-running circuit arrangement for operating a load, has at least one switching element, a freewheeling diode connected in an anti-parallel fashion relative to the main current direction of the at least one switching element, a load circuit and a control resonant circuit which comprises at least one control inductor and at least one self-capacitance of the at least one switching element. The at least one switching element has a control electrode, a working electrode and a reference electrode, a capacitance acting between the control and working electrodes that is coupled to the control resonant circuit such that energy is fed into the control resonant circuit by the charging and discharging current of this capacitance, the circuit arrangement having no components for feeding energy into the control resonant circuit by electromagnetic coupling.

Abstract: The invention relates to a novel operating device for lamps, in particular low-pressure gas discharge lamps, in which a SEPIC converter is used for charging a storage transistor from an AC voltage supply. In this case, the SEPIC converter is regulated to an output quantity as regulated variable, its operating frequency being altered. Preferably, only the switch-on time and not the switch-off time of the switching transistor of the SEPIC converter is altered in this case.

Abstract: Fluorescent material from the class of the silicide nitrides, Sr being used as cation, and the suicide nitrides being doped with trivalent Ce.

Abstract: The invention relates to a ballast for operating at least one low-pressure discharge lamp, preferably a three- or four-lamp ballast. In order for all parallel- or series-connected low-pressure discharge lamps (L40-L43) to shine equally bright even in the case of strong dimming, the ballast according to the invention has a transformer (Tr40) for balancing the currents in the lamp branch circuits and a transformer (Tr41) for compensating the losses owing to parasitic capacitances.

Abstract: The headlight bulb includes at least one lamp body (1), at least one luminous element (3) enclosed within the at least one lamp body (1), a lamp base (2) in which the at least one lamp body (1) is fixed and power connectors (4, 5) for supply of energy to the at least one luminous element (3). The lamp base (2) includes a base flange (20) and at least three reference tangs (21), which are arranged on a plane, which is level with the plane of the base flange (20). The base flange (20) further includes three clips (22) arranged around the circumference thereof, which are sprung in a direction perpendicular to the plane of the base flange and which cooperate with the reference tangs (21) to mount the bulb in a headlight.

Abstract: The invention relates to an operating circuit for a discharge lamp, having a detection circuit for identifying the proximity to capacitive operation, which uses lamp current fluctuations for detection purposes.

Abstract: An opto-electronic semiconductor element has a radiation emitting or receiving, that is, radiation active semiconductor chip secured to an electrically conductive base frame. One, or a plurality of chips, are surrounded by a housing which may be integral with or have, separately, a cover. All materials of the housing, as well as of the conductive base frame, have mutually matching thermal coefficients of expansion within the temperature ranges which arise during manufacture and in application of the semiconductive element, singly or as a plurality in a common housing. Glass, quartz glass, ceramic or glass ceramic are suitable for the housing or parts thereof; the conductive base frame is preferably made of cladded or jacketed copper wire or strip with an iron-nickel core. Assembling a plurality of chips in a housing which has a luminescence conversion layer, e.g. a phosphor applied thereto, permits construction of a flat light source.

Abstract: An illumination unit having at least one LED as light source, the LED emitting primary radiation in the range from 300 to 430 nm, this radiation being completely converted into longer-wave radiation by phosphors which are exposed to the primary radiation of the LED, in which unit the conversion takes place at least with the aid of a phosphor which emits green with a peak emission wavelength at 495 to 540 nm and which originates from the class of the Ce-activated sialons, the sialon corresponding to the formula Mp/2Si12−p−qAlp+qOqN16−q:Ce3+, where M=Ca individually or in combination with Sr, with q=0 to 2.5 and p=0.5 to 3.

Abstract: An illumination unit having at least one LED as light source, the LED emitting primary radiation in the range from 300 to 570 nm, this radiation being partially or completely converted into longer-wave radiation by phosphors which are exposed to the primary radiation of the LED, in which unit the conversion takes place at least with the aid of a nitride-containing phosphor which emits with a peak emission wavelength at 430 to 670 nm and which originates from the class of the Ce- or Eu-activated nitrides, oxynitrides or sialons.

Abstract: A sealed-in foil lamp comprising a metal base member of molybdenum and a coating applied on at least a portion thereof, the coating containing ruthenium alone or a ruthenium alloy.

Abstract: Appliance for discharge lamps, which has a load circuit with a resonance point at a resonant frequency fres. In order to start the discharge lamps, the load circuit is fed with a square-wave source voltage Uq, whose period duration Tper multiplied by the resonant frequency fres of the load circuit produces approximately a natural number n which is greater than 1. The pulse duration Tpulse at the source voltage Uq is in a range which is described by the following condition: 0.

Abstract: An electronic converter having an input circuit and an output circuit which, in addition to the converter function, carries out power-factor correction. A control circuit opens and closes an electronic switch as a function of the output voltage from the converter circuit and the voltage which is dropped across a current measurement sensor. The circuit has a logic ground LM and a power ground PM at different electrical potentials.