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. 06, 1998
Filed:
May. 31, 1996
Nippondenso Co., Ltd., Kariya, JP;
Abstract
DC/DC converter 31 boosts an output voltage of a battery 1 having a negative terminal grounded to a vehicle body, and supplies a boosted voltage to a discharge lamp 4 interposed between a positive output terminal and a negative output terminal of battery 1. A lamp current detecting resistance 35, connected in series with discharge lamp 4, detects a lamp current flowing through discharge lamp 4. Lamp voltage detecting resistances 33 and 34 detect a lamp voltage applied to discharge lamp 4. An electric power of DC/DC converter 31 is controlled by lamp power calculating circuit 36 and DC/DC converter drive circuit 37 based on the lamp current detected by lamp current detecting resistance 35 and the lamp voltage detected by lamp voltage detecting resistances 33 and 34. Discharge lamp 4 and lamp current detecting resistance 35 are connected at a connecting point 'a' which is grounded. An excessive current flowing through lamp current detecting resistance 35 is detected to stop electric power supply to discharge lamp 4. Detection of the excessive current is inhibited until a predetermined period of time has elapsed after starting a lighting operation of discharge lamp 4.