Osram Gesellschaft MIT Beschraenkter Haftung

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Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Osram Ag

Patent-treuhand-gesellschaft F&uuml;r Elektrische Gl&uuml;hlampen Mbh

Osram Gesellschaft MIT Beschrankter Haftung

Juergen Klier

Richard Pfaller

Rene Twardzik

A detector circuit for actuating at least one fluorescent lamp may be configured such that the actuation of at least one fluorescent lamp occurs as a function of a first signal at a first input and as a function of a second signal at a second input if the first signal and the second signal are each greater than a first prescribed voltage and less than a second prescribed voltage during a start-up phase.

Detector circuit and method for actuating a fluorescent lamp

A detector circuit for controlling at least one fluorescent lamp is provided, wherein the detector circuit is configured such that an inactive fluorescent lamp can be detected if a first signal is present at least one of a first input and a second signal is present at a second input in a detection interval after a start-up phase.

Detector circuit and method for controlling a fluorescent lamp

Circuit arrangement for operation of discharge lamp comprising an input for connecting a supply alternating current voltage. A startup supply device is provided with an input and an output, where the input is connected to an input of a control circuit and the output is connected to another input of the control circuit. The startup supply device provides a startup supply voltage at the output of the startup supply device and hence reduces the stand-by losses.

Circuit arrangement and method for the operation of at least one discharge lamp

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 (L -L ) to shine equally bright even in the case of strong dimming, the ballast according to the invention has a transformer (Tr ) for balancing the currents in the lamp branch circuits and a transformer (Tr ) for compensating the losses owing to parasitic capacitances.

Ballast for operating at least one low-pressure discharge lamp

The invention relates to a circuit arrangement for operating at least one discharge lamp, the circuit arrangement having a half-bridge inverter (Q,Q,) with a downstream load circuit (L,C,LP,C,), at least one coupling capacitor (C,) which is connected to the load circuit (L,C,LP,C,) and to the half-bridge inverter (Q,Q,), and a drive device (A,) of the half-bridge inverter (Q,Q,). According to the invention, the circuit arrangement has a reference voltage source (R,R,) and a detector circuit (DE,) which detector circuit compares the voltage drop across the at least one coupling capacitor (C,) or the voltage drop, divided downwards by a voltage divider, across the at least one coupling capacitor (C,) with the reference voltage of the reference voltage source (R,R,), and generates an output signal for driving the half-bridge inverter (Q,Q,).

Circuit arrangement for detecting rectification of discharge lamps

In electronic ballast having inverter rectifiers for fluorescent lamps, a regulation of the lamp current or of the lamp power is usually used in order to stabilize the lighting current independently of tolerances of the electrical properties of the fluorescent lamp or their aging phenomena. When such a regulation is simultaneously utilized for dimming the fluorescent lamp, difficulties arise at the lower limit of the dimming range at, for example, 1% of the nominal light power. The range of brightness at the lower limit is regulated on the basis of an additional regulation, dependent on the discharge resistance of the fluorescent lamp. An auxiliary measured quantity resulting therefrom is superimposed on the actuating quantity of the regulator that results from a reference/actual value comparison of the current or power regulation for the purpose of stabilizing the lamp current.

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Traunreut, Germany

Juergen Klier