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:
Aug. 28, 2001
Filed:
May. 01, 2000
Daoshen Chen, Huntsville, AL (US);
Bryce L. Hesterman, Madison, AL (US);
Universal Lighting Technologies, Nashville, TN (US);
Abstract
An electronic ballast apparatus for powering one or more gas discharge lamps includes an inverter that is controlled by an inverter control circuit. The inverter control circuit adjusts certain ballast operating characteristics in order to operate the lamps under nearly the same operating conditions irrespective of how many lamps are connected to the ballast. The inverter control circuit includes a lamp quantity sensor, a regulator circuit and an end-of-lamp-life sensor. The lamp quantity sensor provides a lamp quantity signal that indicates how many lamps are connected to the ballast. The regulator circuit includes a reference adjustment circuit that receives the lamp quantity signal and provides a scaled reference signal to a reference terminal of an error amplifier. The error amplifier also has a feedback terminal that receives a signal that is proportional to the power delivered by the inverter to the lamps. The regulator circuit provides a signal to an inverter power control circuit to ensure that the total power delivered by the inverter to the lamps is proportional to the number of lamps connected to the ballast. The lamp quantity signal is also used to adjust the operation of the end-of-lamp-life sensor.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile