Doppler effect speedometer
US4914638A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 28, 1984 |
| Grant date | Apr 3, 1990 |
| Priority date | — |
| Expiry date | Feb 28, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S367/902
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A speedometer is provided for determining speed by providing a sound signal at a first frequency, receiving a second signal which is the reflection of the first signal, and determining difference in frequency between the first and second signals created by the Doppler Effect. A speech synthesis chip within the speedometer provides a verbal indication of velocity. In this way, a person using the provided speedometer does not have to look at a dial or other visual indicator. Provided within the speedometer is a heat-sensitive transducer for measuring the air temperature. In this way, the speedometer can take into account the change in the speed of sound with respect to temperature when calculating velocity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.