Surface elevation measuring apparatus
US4227401A · kind A · utility
2Cited by
3References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 15, 1979 |
| Grant date | Oct 14, 1980 |
| Priority date | — |
| Expiry date | May 15, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/125
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A terrain probe for sensing the elevation of a terrain surface whose prof is being measured and followed. A two-phase induction motor will raise or lower the terrain probe in response to either an increase or decrease in the elevation of the terrain surface. A four arm bridge circuit, which has an arm enclosed within the terrain probe, in combination with a low frequency oscillator, a differential amplifier, and power amplifier generate a sinusoidal drive signal which controls the two-phase induction motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.