The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 2004
Filed:
Dec. 20, 2002
Applicant:
Inventors:
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 3/702 ;
U.S. Cl.
CPC ...
H05B 3/702 ;
Abstract
An operating circuit for a discharge lamp (LP) having preheatable electrodes includes a device (C , T , T , T , G) for preheating the electrodes. The device includes a resonant circuit (C , T ) which oscillates during preheating. During operation, the operating circuit produces an AC voltage having a frequency that is moved through a frequency range, records the response of the resonant circuit (C , T ) by measuring an electrical variable (UC ), and identifies the resonant frequency of the resonant circuit (C , T ) from the electrical variable (UC ), and preheats the electrodes by setting the frequency of the AC voltage to the resonant frequency.