Operating device and method for operating gas discharge lamps
AssigneePatent-Treuhand-Gesellschaft Fur Elektrisch Gluhlampen Mbh
InventorsChristian Breuer, Ralf Weidemann
Life of this patent
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Abstract
The invention relates to an operating device for operating high-pressure gas discharge lamps. Of particular concern is an operating device having a controller for start-up of high-pressure gas discharge lamps which provides a shorter start-up phase in comparison with the prior art. This is achieved by a lamp state detector which recognizes, after starting, that a hot lamp is present and thereupon increases the start-up current.
Claims12
An operating device for operating high-pressure gas discharge lamps, the operating device comprising:
- an apparatus which is suitable for triggering starting of a connected high-pressure gas discharge lamp, and
- a setting device which is suitable for limiting a lamp current of connected high-pressure gas discharge lamps to a limit current value,
- characterized in that the operating device further comprises:
- a lamp state detector which is designed such that, in a time window which follows on from starting and is shorter than a start-up phase, it evaluates a running voltage of a connected high-pressure gas discharge lamp or a value proportional thereto and from this derives a state variable which is suitable for distinguishing between a cold and a hot high-pressure gas discharge lamp, and
- a control device which inputs the limit current value to the setting device as a function of the state variable, and
- further characterized in that the lamp state detector contains a subtracter having two inputs and one output, the value of the running voltage at a time in the time window being applied to one input, a predetermined rated value being applied to the other input, and a difference being provided at the output of the subtracter, from which difference the lamp state detector forms the state variable.
An operating device for operating high-pressure gas discharge lamps, the operating device comprising:
- an apparatus which is suitable for triggering starting of a connected high-pressure gas discharge lamp, and
- a setting device which is suitable for limiting a lamp current of connected high-pressure gas discharge lamps to a limit current value,
- characterized in that the operating device further comprises:
- a lamp state detector which is designed such that, in a time window which follows on from starting and is shorter than a start-up phase, it evaluates a running voltage of a connected high-pressure gas discharge lamp or a value proportional thereto and from this derives a state variable which is suitable for distinguishing between a cold and a hot high-pressure gas discharge lamp, and
- a control device which inputs the limit current value to the setting device as a function of the state variable, and
- further characterized in that the control device contains a comparator, which compares the state value with a stored comparison value, and inputs a limit current for hot lamps to the setting device if the state variable is greater than the comparison value, and inputs a limit current value for cold lamps to the setting device if the state variable is less than the comparison value.
An operating device for operating high-pressure gas discharge lamps, the operating device comprising:
- an apparatus which is suitable for triggering starting of a connected high-pressure gas discharge lamp, and
- a setting device which is suitable for limiting a lamp current of connected high-pressure gas discharge lamps to a limit current value,
- characterized in that the operating device further comprises:
- a lamp state detector which is designed such that, in a time window which follows on from starting and is shorter than a start-up phase, it evaluates a running voltage of a connected high-pressure gas discharge lamp or a value proportional thereto and from this derives a state variable which is suitable for distinguishing between a cold and a hot high-pressure gas discharge lamp, and
- a control device which inputs the limit current value to the setting device as a function of the state variable, and
- further characterized in that the time window is shorter than 3 seconds.
Dependencies are inferred from the claim text.