Apparatus for measuring the quantity of airflow passing through an intake passage of an engine
US4565091A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1985 |
| Grant date | Jan 21, 1986 |
| Priority date | — |
| Expiry date | Apr 16, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/6983
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disposed in an intake pipe of an engine is a temperature-sensitive element formed of a resistance element whose resistance value varies with temperature. A heating current is supplied to the temperature-sensitive element through a transistor. The voltage of the heating current is set by a constant-voltage circuit. The temperature of the temperature-sensitive element is compared with a reference temperature of an auxiliary temperature-sensitive element. When the temperature of the temperature-sensitive element is increased to a predetermined level, an output signal is delivered from a comparator. A flip-flop circuit is reset by the output signal from the comparator, and is set by a start pulse signal. When the flip-flop circuit is set, the transistor is turned on, allowing the heating current to be supplied to the temperature-sensitive element. A burning-off instruction signal is supplied to a monostable multivibrator, and a signal with a duration suited for the burning-off operation is delivered from an AND circuit. In response to the output signal from the AND circuit, the flip-flop circuit is held set, and a reference voltage supplied to the differential amplifier is changed to a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.