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:
Jul. 25, 1995
Filed:
Jul. 02, 1993
Yasuo Torikoshi, Kawasaki, JP;
Hiromitsu Ishii, Chiba, JP;
Hochiki Kabushiki Kaisha, Tokyo, JP;
Abstract
A thermal analog fire detector which is excellent in measurement precision and resolution in both the high and low temperature ranges and which has a wide range of measuring temperatures. A constant voltage E from a constant voltage circuit is supplied to a CPU, an A/D converter and a constant current circuit. The constant current circuit is connected in series to a thermistor. The constant current circuit is constructed to supply a constant current, the value of which being variable in a plurality of stages, to the thermistor controlled by the CPU. The CPU switches the constant current of the constant current circuit according to the measured temperature data. A voltage V across the thermistor is converted into digital data by the A/D converter, and then the converted data is supplied to the CPU.