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. 10, 2012
Filed:
Jan. 25, 2007
Hiroshi Nakano, Hitachi, JP;
Masamichi Yamada, Hitachinaka, JP;
Masahiro Matsumoto, Hitachi, JP;
Izumi Watanabe, Hitachinaka, JP;
Hiroshi Nakano, Hitachi, JP;
Masamichi Yamada, Hitachinaka, JP;
Masahiro Matsumoto, Hitachi, JP;
Izumi Watanabe, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.