Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Osram Ag

Osram Gesellschaft MIT Beschraenkter Haftung

Osram Gmbh

Osram Gesellschaft MIT Beschrankter Haftung

Herbert Kästle

Andreas Huber

Klaus Stockwald

Peter Niedermeier

Walter Limmer

Thomas Rossmanith

A circuit arrangement for operating a high-pressure discharge lamp, comprising at least one first electronic switch and one second electronic switch in a half-bridge arrangement; a supply voltage terminal for supplying the half-bridge arrangement with a DC voltage signal; a load circuit, which comprises a lamp inductor and is coupled firstly to the half-bridge center point and secondly to at least one terminal for connecting the high-pressure discharge lamp; a drive circuit for providing at least one first and one second drive signal for the first electronic switch and the second electronic switch, the drive circuit being adapted to provide the first and the second drive signal in such a way that the clock thereof is firstly swept between a first and a second frequency; wherein the drive circuit is furthermore adapted to modulate the first and the second drive signal with a predeterminable third frequency, with the modulation with the predeterminable third frequency being single-tone frequency modulation, with the result that, in the amplitude spectrum of the first and the second drive signal, at least one first, one second and one third spectral line appear, the first spectral line corresponding to the instantaneous frequency of the swept clock, and the second and the third spectral lines, in terms of absolute value, appearing at an interval with respect to the predeterminable third frequency, symmetrically with respect to the first spectral line, and that, in the power spectrum of the signal, at the terminal for connecting the high-pressure discharge lamp, a spectral line at the predeterminable third frequency results.

Circuit arrangement and method for operating a high-pressure discharge lamp

Disclosed is a circuit arrangement for supplying a lamp wattage to a high-pressure discharge lamp (Lp) in the form of an alternating current having an operating frequency. The alternating current is generated by a full bridge that is composed of two half-bridge branches. The lamp wattage can be adjusted via the phase which the two half-bridge branches have relative to each other. The lamp wattage is modulated by means of the transmission function of an interface if the operating frequency is frequency-modulated. Said modulation of the lamp wattage can be compensated by adequately correcting the phase.

Circuit arrangement with continuously oscillating modulated operating frequency, and method, for the operation of high-pressure gas discharge lamps

In the case of an apparatus for providing a sinusoidally amplitude-modulated operating voltage, two switches are arranged in the form of a half bridge, and an LC element is arranged downstream of the half bridge. The first switch is driven by a first square-wave signal in a clocking with the amplitude modulation frequency per clock cycle, and the second switch (QLOW) is driven by a second square-wave signal, which is shorter than the first signal, with a temporal offset with respect to the first signal in each clock cycle. The LC element (LMOD, CMOD) acts as a filter for the signal resulting from the driving of the switches at a connection point (K) between the switches and allows a DC voltage component and a sinusoidal component of the signal with the fundamental frequency of the clocking to pass through, but substantially filters out harmonics.

Apparatus for providing a sinusoidally amplitude-modulated operating voltage, lighting system and method for generating an amplitude-modulated voltage

A ballast for at least one lamp at least two switches arranged in series; a control circuit for alternately opening and closing the two switches; a connection for applying a supply voltage to the two switches; a resonant starting circuit coupled on the input side to the junction point between the two switches and on the output side to a first connection for the lamp, the resonant starting circuit having a resonant inductance arranged in series with the junction point between the two switches (S, S) and the first connection for the lamp, and a resonant capacitance arranged for alternating current purposes in parallel with the first and second connections for the lamp, a first braking inductance which, for alternating current purposes, is firstly arranged in series with the first of the two connections for the lamp and secondly in parallel with the resonant capacitance.

Ballast with braking inductance

The operating method is based on the simultaneous application of FM and AM, and is distinguished by passing through three operating states, specifically a warm-up phase, an impressing phase and the continuous operation. In the warm-up phase, the f_hor is selected as fundamental frequency of the AM, or an AM is dispensed with. The impressing phase is distinguished by a temporally changing AM deviating from the conditions of the continuous operation and having an AM degree different from zero. In the continuous operation, constant conditions of the AM in the case of which the f_hor is reached as fundamental frequency of the AM, and the AM degree is at 20 to 25% are characteristic.

Operating method and system for the resonant operation of high-pressure lamps in longitudinal mode

Lighting system for high-pressure discharge lamps which can generate a lamp voltage UL which is amplitude and, if necessary, frequency-modulated. The frequency modulation is provided by an inverter whose inverter frequency is modulated. The inverter is fed by a clocked d.c. voltage supply which emits an operating voltage Uwhich is amplitude-modulated.

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Traunstein, Germany

Herbert Kästle