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:
Jan. 12, 1999
Filed:
Apr. 02, 1997
Applicant:
Inventor:
Robert Stephen Potratz, Overland Park, KS (US);
Assignee:
Nellcor Puritan-Bennett, Pleasanton, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
315291 ; 315224 ; 315307 ; 315309 ;
Abstract
A lamp drive circuit periodically energizes a lamp above its rated voltage and current for rapid illumination of the lamp. In the preferred embodiment, the lamp is connected in a voltage divider and the circuit monitors the voltage drop across the lamp. The voltage drop is indicative of the lamp resistance and thereby the temperature. When the voltage drop reaches a predetermined limit corresponding to the temperature rating of the lamp, it is de-energized and allowed to cool during the remainder of the cycle thereby enabling a high modulation frequency.