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. 23, 2003
Filed:
Mar. 13, 2002
Christopher P. Henze, Lakeville, MN (US);
Nicollet Technologies Corporation, Minneapolis, MN (US);
Abstract
A lamp power measurement circuit measures average power delivered to a gas discharge lamp. The circuit includes a voltage sensor having a first measurement output representative of AC voltage across the lamp and a current sensor having a second measurement output representative of AC current through the lamp. A first absolute value circuit is coupled in series with the first measurement output and has a first absolute value output. A second absolute value circuit is coupled in series with the second measurement output and has a second absolute value output. A pulse width modulator modulates one of the first and second absolute value outputs with the other of the first and second absolute value outputs and has a pulse width modulated output. A low-pass filter is coupled in series with the pulse width modulated output and has a DC voltage output representative of average power dissipated through the lamp.