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. 18, 1990
Filed:
Feb. 14, 1989
Jeffrey A Jorgensen, Bothell, WA (US);
Avtech Corporation, Seattle, WA (US);
Abstract
A ballast having a converter for converting input power into DC at a high frequency and a commutator for converting the DC to AC at a low frequency to cause light emission from a gas discharge lamp. The converter also contains a transformer for converting the input AC to a low voltage AC for heating the filaments in the lamp. Current and Voltage sensors associated with the commutator provide feedback to control circuitry which allows power conversion after the filaments heat and the voltage to the lamp to increase to the voltage required to start the lamp even when different starting voltage requirement lamps are used. After the lamp starts, the lamp is soley current mode controlled. By frequency modulation of the commutator, both power and crest factor can be controlled.