Patent US3775749A successfully refreshed from Google Patents.
US3775749A
Expired / Lapsed
US
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Device for measuring seismic signals
Assignee: COPCO AB
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Filing: 1970-09-14
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Granted: 1973-11-27
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Expires: 1990-09-14
Abstract
Abstract A device for measuring seismic signals includes a transducer for generating electric signals representative of seismic ground motion, a variable-gain amplifier for amplifying the signals, a recorder for recording the output signal from the amplifier and a control device including an amplifier and rectifier which receives the output signal and generates, in response thereto, a gain-control signal, the magnitude of which varies with respect to the frequency of the output signal such that the gain of the amplifier and the voltage applied to the recorder decreases with increasing frequency of the signals.
Inventors
- 👤 R Tegholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:31
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/24; G01V1/245
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
A device for measuring seismic signals comprising a. at least one seismic transducer for generating electric signals representative of seismic ground motion, b. a variable-gain amplifier for amplifying said electric signals, c. recording means for recording the output signal from said amplifier against time, and d. control means for controlling the gain of said amplifier, said control means comprising means for receiving said output signal from said amplifier and for generating in response thereto a gain-control signal having a magnitude which varies with respect to the frequency of the output signal from said amplifier such that the gain of said amplifier and the voltage applied to the recording means decreases with increasing frequency of the electric signals.
Claim 2
Independent Claim
117 words
A device for measuring seismic signals comprising a. at least one seismic transducer for generating electric signals representative of seismic ground motion, b. a variable-gain amplifier for amplifying said electric signals, c. recording means for recording the output signal from said amplifier against time, and d. control means for controlling the gain of said amplifier, said control means comprising means for receiving said output signal from said amplifier and for generating in response thereto a gain-control signal having a magnitude which varies with respect to the frequency of the output signal from said amplifier such that the gain of said amplifier and the voltage applied to the recording means decreases with increasing frequency of the electric signals.
Claim 3
Dependent Claim
65 words
A device as claimed in claim 1 wherein said control means comprises means causing the output signal of said amplifier applied to said recording instrument to decrease with increasing frequency of the input signal applied to the amplifier and to cause the output signal to remain at a substantially constant value with change in the magnitude of said input signal above a predetermined minimum magnitude.
Claim 4
Dependent Claim
40 words
A device as claimed in claim 1 wherein said control means comprises means to generate a gain-control signal which varies substantially inversely in proportion to the frequency above a predetermined lowest frequency of the inpuT signal applied to the amplifier.
Claim 5
Dependent Claim
20 words
A device as claimed in claim 1 wherein said control means comprises an amplifier and a rectifier arranged in series.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |