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:
May. 17, 1988
Filed:
Apr. 08, 1986
Minoru Izawa, Toyota, JP;
Ryohei Doi, Aichi, JP;
Ritsuo Suzuki, Aichi, JP;
Kenichi Kinoshita, Aichi, JP;
Abstract
A lamp failure detecting device for automobile consists of a lamp circuit including a plurality of lamps connected in parallel, a current-detecting resistance connected to a power-supply source through the lamp circuit in series, a first voltage divider circuit including resistances to which a voltage divided by the current detecting resistance and the lamp circuit is applied a second voltage divider circuit including resistances to which a voltage supplied from the power-supply source is applied and a comparator circuit comparing the difference between the divided voltages in the voltage divider circuits to produce a a failure detection signal. Diodes are provided in the first and second voltage divider circuits respectively in the forward direction. Non-linearity of the current flowing through the lamps for the change of the power-supply voltage is corrected by the diodes.