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:
Mar. 07, 2000
Filed:
Nov. 19, 1997
Applicant:
Inventor:
Masuo Akamatsu, Hitachinaka, JP;
Assignee:
Hitachi, Ltd., , JP;
Primary Examiner:
Int. Cl.
CPC ...
G01F / ;
U.S. Cl.
CPC ...
7320417 ; 731182 ; 7320415 ;
Abstract
A heating resistor type air flow-meter has a ratio-meter circuit comprising a proportional circuit for outputting a signal V.sub.out proportional to an input voltage V.sub.in a multiplying circuit for outputting a multiplied signal V.sub.m proportional to a product of a voltage difference VD between an internal reference voltage VINT and an external reference voltage VREF and the voltage signal V.sub.in and an adding circuit for adding the output signal V.sub.p of the proportional circuit and the output signal V.sub.m of the multiplying circuit.