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. 15, 2009
Filed:
Mar. 07, 2006
Masaki Tada, Osaka, JP;
Rihito Shoji, Osaka, JP;
Masaki Tada, Osaka, JP;
Rihito Shoji, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A highly accurate gas sensor includes a circuit having an improved S/N ratio. First ends of a heat generating element and reference resistor brought into contact with a detected gas are commonly connected, and second ends are respectively connected to a first switch. The first switch is connected with a power source apparatus for supplying a current to the heat generating element or reference resistor. A voltage measuring portion measures a voltage across the heat generating element or reference resistor. An operating portion switches the first switch between the reference resistor and heat generating element by a predetermined timing by determining a condition of controlling a power source apparatus for supplying at leaststages of step-like currents to the heat generating element from the voltage across the reference resistor. A voltage measuring portion measures the voltage across the heat generating element and calculates a concentration of a detected gas.