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US4001798A
Expired / Lapsed
US
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Self-contained sensor
Assignee: Boeing North American Inc
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Filing: 1975-09-18
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Granted: 1977-01-04
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Expires: 1995-09-18
Abstract
Abstract A sensor for remotely monitoring a physical stimulus is rendered completely self-contained by utilizing the equivalent electrical signal transduced from the stimulus to power an A. C. signal source as well as to modulate the A. C. signal generated therefrom before transmitting the modulated A. C. signal to the remote monitoring location.
Inventors
- 👤 Roland L. Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:21
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/16; E; E21; E21C; E21C35/00; E21C35/18; E21C39/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
A self-contained sensor, comprising: a transducer for converting a physical stimulus to an equivalent electrical signal; a voltage controlled oscillator having a resistive-capacitive twin-T network in its feedback path, including a field effect transistor operated as a voltage controlled resistor in the middle leg resistor of said twin-T network; circuit means for applying the equivalent electrical signal to said oscillator for powering it including means for rectifying and filtering the signal; circuit means for frequency modulating the output of said oscillator by the equivalent electrical signal by applying it to said field effect transistor, including means for rectifying and filtering the signal, and circuit means for transmitting the modulated output of said oscillator to a remote location.
Claim 2
Dependent Claim
117 words
A self-contained sensor, comprising: a transducer for converting a physical stimulus to an equivalent electrical signal; a voltage controlled oscillator having a resistive-capacitive twin-T network in its feedback path, including a field effect transistor operated as a voltage controlled resistor in the middle leg resistor of said twin-T network; circuit means for applying the equivalent electrical signal to said oscillator for powering it including means for rectifying and filtering the signal; circuit means for frequency modulating the output of said oscillator by the equivalent electrical signal by applying it to said field effect transistor, including means for rectifying and filtering the signal, and circuit means for transmitting the modulated output of said oscillator to a remote location.
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) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |