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:
Feb. 09, 1982
Filed:
Dec. 28, 1979
Fujio Kitayama, Omoriniski, JP;
Niles Parts Company, Ltd., Tokyo, JP;
Abstract
A fault detection apparatus for use with a double-filament lamp utilizes the temperature-related changes in resistance of the non-energized filament to indicate a break in the energized filament. The circuit of the apparatus includes, for each filament, a first voltage dividing network in parallel with the filament and which includes the other filament as a voltage dividing resistance and a second voltage dividing network including the filament which establishes a reference voltage. A comparator is activated to energize a warning lamp when the sensed voltage at a specific voltage dividing point in the network is changed due to the temperature-related changes in the resistance value of the non-energized filament when the energized filament is broken.