Thermally sensing type flowing velocity measuring apparatus
US5750893A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1995 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Jun 20, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/692
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Both of voltage range and supplied power range of a heater can be enlarged, one-sided power source for a driving circuit can be realized easily, power source voltage can be lowered, and flowing velocity can be measured with high accuracy. First reference resistor is connected in series to fluid temperature measuring body, and second reference resistor is connected in series to heater temperature sensor. Temperature setting resistor for determining set temperature difference between the heater temperature sensor and the fluid temperature sensor is connected in series to the fluid temperature sensor. Bridge circuit is constructed in such way. The voltage of heater temperature sensor is inputted to non-inverted input terminal of differential amplifier, while the voltage of fluid temperature measuring body and temperature setting resistor is inputted to inverted input terminal of the same. The output terminal of the differential amplifier is connected to a buffer circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.