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. 11, 2000
Filed:
Nov. 23, 1998
James M Williams, Palo Alto, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
A power-supply and control circuit is provided for driving a fluorescent lamp from a low-voltage direct current (DC) power source such as a battery. The circuit includes a converter that converts low-voltage DC to high voltage alternating current (AC). The converter includes a feedback ceramic step-up transformer that amplifies the AC signal to a level sufficient to illuminate the lamp, and also provides a feedback signal that can be used to monitor the resonance frequency of the transformer. The power supply and control circuit also includes a first feedback loop that regulates the lamp current amplitude and a second feedback loop that forces the converter to operate at the transformer's resonant frequency.