US3744044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic system to detect objects in confined volume
Assignee: Individual
•
Filing: 1971-04-21
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Granted: 1973-07-03
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Expires: 1991-04-21
Abstract
Abstract A system to detect changes in the contents of a defined sensitive volume wherein a detector having an active resonant circuit is connected in an oscillator circuit to create an internal field in the defined sensitive volume, the frequency of the oscillator being shifted by a sudden change in the contents of the defined sensitive volume affecting the internal field. A receiver is coupled to the oscillator circuit and responsive to changes in the frequency of the oscillator to produce an output indicative thereof. Feedback means connected between the output of the receiver and the oscillator provide tracking between the oscillator and the receiver in the zero to low frequency range. Detect means are connected to the output of the receiver to produce a detect signal in response to a change in the contents of the defined sensitive volume affecting the internal field. The system also includes indication means connected to the output of the detect means activated in response to detect signals to provide an indication of a change in the contents of the defined sensitive volume affecting the internal field, and error prevention means connected to the detect means and the indication means operative to prevent activation of the indication means in the event erroneous detect signals are produced.
Inventors
- 👤 R Vosteen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:46
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/101; H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/95; H03K17/9502; H03K17/9505; H03K17/952; H03K17/9537; H03K17/9542; H03K17/9545
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
204 words
A system to detect changes in the contents of a defined sensitive volume comprising: a detector having an active resonant circuit connected in an oscillator circuit to create an internal field in the defined sensitive volume, the frequency of the oscillator being shifted by a sudden change in the contents of the defined sensitive volume affecting the internal field, a receiver coupled to the oscillator circuit and responsive to changes in the frequency of the oscillator to produce an output indicative thereof, feedback means connected between the output of the receiver and the oscillator to provide tracking between the oscillator and the receiver in the zero to low frequency range, detect means connected to the ouTput of the receiver to produce a detect signal in response to a change in the contents of the defined sensitive volume affecting the internal field, indication means connected to the output of the detect means activated in response to detect signals to provide an indication of a change in the contents of the defined sensitive volume affecting the internal field, error prevention means connected to the detect means and the indication means operative to prevent activation of the indication means in the event erroneous detect signals are produced.
Claim 2
Independent Claim
204 words
A system to detect changes in the contents of a defined sensitive volume comprising: a detector having an active resonant circuit connected in an oscillator circuit to create an internal field in the defined sensitive volume, the frequency of the oscillator being shifted by a sudden change in the contents of the defined sensitive volume affecting the internal field, a receiver coupled to the oscillator circuit and responsive to changes in the frequency of the oscillator to produce an output indicative thereof, feedback means connected between the output of the receiver and the oscillator to provide tracking between the oscillator and the receiver in the zero to low frequency range, detect means connected to the ouTput of the receiver to produce a detect signal in response to a change in the contents of the defined sensitive volume affecting the internal field, indication means connected to the output of the detect means activated in response to detect signals to provide an indication of a change in the contents of the defined sensitive volume affecting the internal field, error prevention means connected to the detect means and the indication means operative to prevent activation of the indication means in the event erroneous detect signals are produced.
Claim 3
Dependent Claim
20 words
A system to detect changes as recited in claim 1 wherein there is tracking of the oscillator to the receiver.
Claim 4
Dependent Claim
29 words
A system to detect changes as recited in claim 2 wherein the feedback means comprise an integrator to reduce the average output error of the receiver to substantially zero.
Claim 5
Independent Claim
228 words
A system to detect changes in the contents of a defined sensitive volume comprising: a detector having an active resonant circuit connected in an oscillator circuit to create an internal field in the defined sensitive volume, the frequency of the oscillator being shifted by a sudden change in the contents of the defined sensitive volume affecting the internal field, a receiver coupled to the oscillator circuit and responsive to changes in the frequency of the oscillator to produce an output indicative thereof, signal conditioning means comprising a signal-to-noise optimizer connected to the output of the receiver to optimize the signal-to-noise ratio of the receiver output, feedback means connected between the signal conditioning means and the oscillator to provide tracking between the oscillator and the receiver in the zero to low frequency range, detect means connected to the output of the signal conditioning means to produce a detect signal in response to a change in the contents of the defined sensitive volume affecting the internal field, indication means connected to the output of the detect means activated in response to detect signals to provide an indication of a change in the contents of the defined sensitive volume affecting the internal field, error prevention means connected to the detect means and the indication means operative to prevent activation of the indication means in the event erroneous detect signals are produced.
Claim 6
Independent Claim
228 words
A system to detect changes in the contents of a defined sensitive volume comprising: a detector having an active resonant circuit connected in an oscillator circuit to create an internal field in the defined sensitive volume, the frequency of the oscillator being shifted by a sudden change in the contents of the defined sensitive volume affecting the internal field, a receiver coupled to the oscillator circuit and responsive to changes in the frequency of the oscillator to produce an output indicative thereof, signal conditioning means comprising a signal-to-noise optimizer connected to the output of the receiver to optimize the signal-to-noise ratio of the receiver output, feedback means connected between the signal conditioning means and the oscillator to provide tracking between the oscillator and the receiver in the zero to low frequency range, detect means connected to the output of the signal conditioning means to produce a detect signal in response to a change in the contents of the defined sensitive volume affecting the internal field, indication means connected to the output of the detect means activated in response to detect signals to provide an indication of a change in the contents of the defined sensitive volume affecting the internal field, error prevention means connected to the detect means and the indication means operative to prevent activation of the indication means in the event erroneous detect signals are produced.
Claim 7
Dependent Claim
20 words
A system to detect changes as recited in claim 4 wherein there is tracking of the oscillator to the receiver.
Claim 8
Dependent Claim
29 words
A system to detect changes as recited in claim 5 wherein the feedback means comprise an integrator to reduce the average output error of the receiver to substantially zero.
Claim 9
Dependent Claim
44 words
A system to detect changes as recited in claim 4 wherein the signal conditioning means further comprise an absolute value generator connected between the signal-to-noise optimizer and the detect means to produce a single polarity output in response to an input of either polarity.
Claim 10
Dependent Claim
50 words
A system to detect changes as recited in claim 7 wherein the signal conditioning means is connected to produce a DC component in the event of detector failure and the error prevention means comprise a detector failure circuit operative in response to said DC component to inactivate the indication means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |