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:
Dec. 20, 2011
Filed:
Mar. 09, 2009
Ka Wai Eric Cheng, Kowloon, HK;
Bangalore Prabhakar Divakar, Kowloon, HK;
Dao Hong Wang, Kowloon, HK;
Chow Norbert Cheung, Kowloon, HK;
Ka Wai Eric Cheng, Kowloon, HK;
Bangalore Prabhakar Divakar, Kowloon, HK;
Dao Hong Wang, Kowloon, HK;
Chow Norbert Cheung, Kowloon, HK;
The Hong Kong Polytechnic University, Hung Hom, Kowloon, HK;
Abstract
The present invention relates to temperature compensation of HID lamps in automobiles. The invention concerns the manner in which the temperature of the HID lamp is accounted for in order to drive the lamp is at appropriate power from hot to cold conditions. In the present invention, the voltage across a capacitor in the temperature compensation circuit is sensed and used as a command signal to anticipate lamp temperature, and accordingly the reference power to the HID lamp is modulated depending on the temperature of the lamp. In the present invention, the lamp is driven with a higher power setting when the lamp is cold and with lower power setting when hot. This adaptive generation of reference power setting depending on the temperature of the lamp is implemented using the voltage across a capacitor in the temperature compensation circuit.