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:
Nov. 28, 2006
Filed:
Jan. 13, 2004
Applicant:
Ryo Ando, Hitachinaka, JP;
Inventor:
Ryo Ando, Hitachinaka, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G01F 1/68 (2006.01);
U.S. Cl.
CPC ...
Abstract
According to the invention, to correct the curvature characteristic in output due to individual differences between frequency output type hot-wire flow meters, a frequency output type hot-wire flow meter includes a heating resistor disposed in the measurement target fluid and a voltage frequency conversion circuit for converting the air flow rate voltage signal that is proportional to the current flowing through the heating resistor. The voltage frequency conversion circuit converts the air flow rate voltage signal non-linearly to generate the output frequency.