Transformerless input for seismic data acquisition system
US3972020A · kind A · utility
13Cited by
6References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1974 |
| Grant date | Jul 27, 1976 |
| Priority date | — |
| Expiry date | Dec 11, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/22
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a long line data acquisition system, an input network is provided for coupling the lines to a data acquisition unit. The network includes the cascade combination of a first filter presenting a low pass frequency response to common mode voltage and a second filter presenting a low pass frequency response to difference mode voltage. The output of the second filter is coupled to an amplifier having high common mode rejection. The network substantially reduces, at the amplifier input, both common mode and difference mode noise picked up by the lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.