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US 5,844,379 AGranted
Circuit arrangement for igniting a high pressure discharge lamp
AssigneeU.S. Philips Corporation
InventorsTheodorus H. Stommen, Theodorus M. Hendriks
Life of this patent
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Abstract
The invention relates to a circuit arrangement for operating a high-pressure discharge lamp. A buffer capacitor is shunted by a branch which comprises a series circuit of a second capactor and a unidirectional element for blocking a current with which the second capacitor charges the buffer capacitor Re-ignition after a zero crossing of the low-frequency alternating current has a comparatively high amplitude so that the lamp re-ignites in a reliable manner.
Claims6
A circuit arrangement for operating a high-pressure discharge lamp, provided with
- first capacitive means,
- a commutator for generating a low-frequency alternating current through the high-pressure discharge lamp from a DC voltage present across the first capacitive means, which commutator comprises
- input terminals coupled to the first capacitive means,
- a load branch which comprises terminals for connection of the high-pressure discharge lamp and inductive means,
- characterized in that the first capacitive means are shunted by a branch which comprises a series circuit of second capacitive means and a unidirectional element for blocking a current with which the second capacitive means charge the first capacitive means.
2 more elements
Dependencies are inferred from the claim text.