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:
Jul. 30, 2002
Filed:
Mar. 19, 2001
Knobel AG Lichttechnische Komponenten, Ennenda, CH;
Abstract
A circuit arrangement comprises four controllable switches (S S ) interconnected to form a full bridge. A warm-up operation is carried out in which there is a switch over between the two bridge diagonals (S S S S ) respectively. The gas discharge lamp (EL) is ignited by way of a series resonant circuit (L C ) which is coupled to the bridge branch. The actual normal operation is effected by switching over at a low frequency between the switches of the two bridge diagonals (S S S S ), with, moreover, one switch (S S ) of the respectively activated bridge diagonal being switched on and off alternately at a high frequency, with this switch (S , S ) being switched on at the high frequency whenever the current (iL ) flowing by way of the bridge branch has reached a minimum value.