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. 21, 2000
Filed:
Aug. 18, 1994
Ole K Nilssen, Barrington, IL (US);
Other;
Abstract
An electronic ballast is powered from a constant-magnitude DC supply voltage and provides a high-magnitude high-frequency voltage at a ballast output across which are connected two lamp-ballast series-combinations, each consisting of an instant-start fluorescent lamp series-connected with a ballasting capacitor. An auxiliary capacitor is connected in series with the ballast output, thereby having the total ballast output current flowing through it and causing an auxiliary high-frequency voltage to develop across its terminals. The constant-magnitude DC supply voltage is provided via a series-combination of a power-line-connected rectifier delivering an unfiltered full-wave-rectified power line voltage across a pair of rectifier DC terminals and an auxiliary DC power supply delivering an auxiliary DC voltage across a pair of auxiliary DC terminals from which, under open circuit condition, is available a DC voltage of magnitude equal to the peak magnitude of the full-wave-rectified power line voltage. Under short circuit condition, the absolute magnitude of the auxiliary DC current delivered from the auxiliary DC terminals is equal to the peak absolute magnitude of the sinusoidal current intended to be drawn from the power line under normal ballast operation. Via a transformer and rectifiers, the auxiliary DC voltage and current are derived from the auxiliary high-frequency voltage. As an overall result, the current drawn from the power line is in fact nearly sinusoidal.