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:
Nov. 13, 2001
Filed:
Dec. 20, 2000
Applicant:
Inventor:
Franz Raiser, Munich, DE;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F 1/00 ;
U.S. Cl.
CPC ...
G05F 1/00 ;
Abstract
A ballast for a gas discharge lamp having an inverter. A DC voltage source feeds the ballast. A bridge circuit is arranged in parallel with the DC voltage source. The bridge circuit has first and second controllable switches. The midpoint of the bridge is connected to a load circuit having the gas discharge lamp. The gas discharge lamp has first and second electrodes. A control circuit controls the pulse duty factor of the first and second switches. The pulse duty factor is not equal to 50%. The control circuit controls the pulse duty factor such that the first and second electrodes are subjected to essentially the same thermal load on average.