Osram Sylvania Inc.

Osram Ag

Osram Gesellschaft MIT Beschraenkter Haftung

Osram Gmbh

Osram Gesellschaft MIT Beschrankter Haftung

Osram S.p.a. - Societa' Riunite Osram Edison Clerici

Uwe Liess

Bernd Rudolph

Tobias Frost

Naveen Yadlapalli

Filippo Branchetti

An emergency supply circuit for an electronic ballast may include: an output line to feed a supply input of the ballast; a first line to receive a mains supply signal; a second line to receive an emergency supply signal from a battery, with a converter interposed in said second line to boost said supply signal, a switch to alternatively connect said output line to said first or said second line; a controller sensitive to the absence of said mains supply signal and to the charge level of said battery, said controller to produce switching of said switch to connect said output line to said second line in the absence of said mains supply signal on said first line, whereby said output line receives said supply signal, and dimming interface circuitry to drive said dimming control input of said ballast when said output line is connected to said second feed line.

Emergency power supply circuit for dimmable electronic ballasts and related method

A ballast () for powering one or two gas discharge lamps () includes an inverter (), an output circuit (), and a control circuit (). During a period prior to startup of inverter (), control circuit () monitors a signal within output circuit () in order to determine the presence of lamps with intact filaments that are present at the ballast output connections (). Preferably, control circuit () is realized by a programmable microcontroller which implements a dual timing scheme in order to accurately determine the number of lamps with both filaments intact. The resulting determination may be used for various purposes, such providing appropriate levels of filament heating and/or for setting thresholds for accurately detecting and protecting against various lamp fault conditions.

Ballast with lamp filament detection

A ballast () for powering one or more gas discharge lamps () includes an inverter (), an output circuit (), a filament heating control circuit (), and a control circuit (). During a lamp filament detection period prior to startup of inverter (), control circuit () monitors a signal within output circuit () in order to determine the number of lamps with intact filaments that are present at the ballast output connections (). During a lamp type detection period following startup of inverter (), control circuit () monitors a current within filament heating control circuit () in order to determine the type of lamp(s) present at ballast output connections (). The determinations as to the number of lamps and the type of lamps are utilized by control circuit () to provide an appropriate level of heating to the lamp filaments. Preferably, control circuit () is realized by a microcontroller that is programmed with data relating to the different lamp types that may be powered by ballast ().

Ballast with lamp-diagnostic filament heating, and method therefor

A circuit arrangement for operation of lamps, including a half-bridge arrangement which has an upper and a lower electronic switch (Q, Q), which are connected in series, each having a control connection and forming a neutral point (N) at their connection point. The circuit arrangement further includes: a load circuit, in which a load circuit current (IL) flows, is connected to the neutral point (N); a feedback device; a stop device; a timer coupled to the input of the stop device; and a trigger device. A sequence controller is configured to preset an on-time (t) during the preheating time of the electrodes of the lamps, by means of the timer, and after the preheating time of the electrodes of the lamps, this on-time is continuously increased until it corresponds at least to one quarter of the period duration of the resonant frequency of the reactance network.

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Treviso, Italy

Uwe Liess