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:
Oct. 20, 1998
Filed:
Sep. 08, 1997
Takayuki Itsuji, Hitachinaka, JP;
Masao Akamatsu, Hitachinaka, JP;
Abstract
A heating resistor type air flow meter for measuring the amount of air flow which passes through an intake pipe for an internal combustion engine. The air flow meter has a constant-temperature control circuit for detecting air flow, which has a bridge circuit including a heating resistor and a temperature-sensitive resistor each provided in the intake pipe, and a power amplifier circuit for amplifying a signal from the constant-temperature control circuit to generate an air flow signal. The power amplifier circuit has a plurality of amplification resistors which determine a mu-factor for the amplifier to correct the amount of air flow with respect to variation of temperature. At least an amplification resistor has a temperature coefficient different form that of the other amplification resistor, to compensate variation of the mu-factor of the power amplifier circuit.