Electronic ballast for a high-pressure discharge lamp having a current-measuring device
AssigneePaten-Treuhand-Gesellschaft Fur Elektrisch Gluhlampen Mbh
InventorsAlois Braun, Walter Limmer, Joachim Muhlschlegel, Markus Ziegler
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Abstract
The invention relates to an electronic ballast and to an operating method for high-pressure discharge lamps. During a current measurement, in particular for current regulation, only switching phases of a specific polarity of the current are taken into consideration.
Claims14
An electronic ballast for operating a high-pressure discharge lamp (L)
- having a converter having at least two switching transistors (S1, S2) for the purpose of producing a supply power for the lamp (L)
- using a switching operation for the switching transistors (S1, S2) having switching phases of alternating polarity of the currents through the lamp (L),
- characterized by a current-measuring device (R1, R2, C6) having a measuring resistor (R1),
- which is connected in series with at least one of the switching transistors (S1, S2) and is designed to carry out current measurements only during switching phases of the converter with precisely one of the polarities.
A method for operating a high-pressure discharge lamp (L) having a ballast, in which a supply power for the lamp (L) is produced by a converter having at least two switching transistors (S1, S2), the switching transistors (S1, S2) being operated with switching phases of alternating polarity of the currents through the lamp (L),
- characterized in that, with the aid of a current-measuring device (R1, R2, C6), current measurements are carried out via a measuring resistor (R1) of the current-measuring device (R1, R2, C6) which is connected in series with at least one of the switching transistors (S1, S2), only during switching phases of the converter with precisely one of the polarities.
Dependencies are inferred from the claim text.