Air flow meter of a heating resistor type
US5824895A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1997 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Sep 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/302
- WIPO fieldMeasurement
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.