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:
Sep. 29, 1998
Filed:
Aug. 05, 1996
Robert Beland, St. Marthe sur le Lac, CA;
Pascal Kaufman, Ville de Deux Montagnes, CA;
Transfotec International, St. Eustache, CA;
Abstract
A power supply for a cold cathode tube has a high voltage module coupled directly to the cold cathode tube, and a power control module that provides a power control signal to the high voltage module via low voltage wiring. The power control module has a circuit that compensates for negative resistance of the ionized gas within the cold cathode tube by adjusting a frequency of the power control signal. The power control module also receives a return of from the cold cathode tube, and varies an illumination intensity of the cold cathode tube using a burst modulation technique, and provides shutdown in the event of a ground fault.