US3706981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indicating system for detecting gaseous and non-gaseous states
Assignee: Individual
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Filing: 1971-02-08
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Granted: 1972-12-19
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Expires: 1991-02-08
Abstract
Abstract A detection system capable of distinguishing between a gaseous state and a non-gaseous state such as a liquid state and/or an ice state including a piezoelectric crystal, an exciter circuit connected to the crystal for producing an alternating current output at the mechanical frequency of the crystal, a measuring circuit connected to the output of the exciter circuit for determining increases and decreases in the amplitude of the output signal, and a signal device connected to the measuring circuit and responsive to increase and/or decrease in measurement of the signal output to produce a signal advisory of the change in the ambient physical conditions to which the crystal is subject in the selected location to advise the presence and/or absence of ice or liquid states relative to a gaseous state or to operate another system in response to the change.
Inventors
- 👤 Atlee S Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:00
CPC Classifications
G; G08; G08B; G08B19/00; G08B19/02; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/296; G01F23/2966; G01F23/2967
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
328 words
A detecting system for distinguishing between a gaseous environmental physical condition and environmental physical conditions other than gaseous such as liquid, ice, etc., by a stronger output signal in the presence of a gas, and a weaker output signal in the presence of conditions other than gas, comprising, a piezoelectric crystal exposable to environmental physical conditions in a selected location; said crystal having a mechanical frequency of vibration affected by the density of ambient physical conditions resulting in a normal undamped relatively stronger amplitude of vibration in the presence of gaseous conditions and a damped weaker amplitude of vibration in the presence of conditions other than gaseous; a body supporting said crystal; means on said body for mounting said body on a member to expose said crystal to ambient physical conditions in a selected location; an exciter circuit including said crystal producing an alternating current output at the normal frequency of said crystal; a signal circuit connected to said exciter circuit output for measuring said exciter circuit output; and a signal device connected to said signal circuit responsive to measurement of said output to advise change in ambient physical conditions occurring bi-directionally between a gaseous state and a non-gaseous state at the selected location to provide a signal indicating that a change has occurred in ambient physical conditions and indicative of the present state(.); said exciter circuit including a current limiting resistor and a zener diode to provide a regulated voltage for an oscillator circuit leading to said piezoelectric crystal; said exciter circuit having an oscillator circuit leading from said piezoelectric crystal including an FET transistor, resistors, and a capacitor forming a biasing network for said transistor; and an inductance and a second capacitor connected through said transistor; said circuit causing said crystal to vibrate and produce an alternating voltage of the crystal frequency across said inductance; should the vibration of said crystal be damped, the ''''ON'''' bias to said transistor is reduced and output voltage is reduced.
Claim 2
Dependent Claim
328 words
A detecting system for distinguishing between a gaseous environmental physical condition and environmental physical conditions other than gaseous such as liquid, ice, etc., by a stronger output signal in the presence of a gas, and a weaker output signal in the presence of conditions other than gas, comprising, a piezoelectric crystal exposable to environmental physical conditions in a selected location; said crystal having a mechanical frequency of vibration affected by the density of ambient physical conditions resulting in a normal undamped relatively stronger amplitude of vibration in the presence of gaseous conditions and a damped weaker amplitude of vibration in the presence of conditions other than gaseous; a body supporting said crystal; means on said body for mounting said body on a member to expose said crystal to ambient physical conditions in a selected location; an exciter circuit including said crystal producing an alternating current output at the normal frequency of said crystal; a signal circuit connected to said exciter circuit output for measuring said exciter circuit output; and a signal device connected to said signal circuit responsive to measurement of said output to advise change in ambient physical conditions occurring bi-directionally between a gaseous state and a non-gaseous state at the selected location to provide a signal indicating that a change has occurred in ambient physical conditions and indicative of the present state(.); said exciter circuit including a current limiting resistor and a zener diode to provide a regulated voltage for an oscillator circuit leading to said piezoelectric crystal; said exciter circuit having an oscillator circuit leading from said piezoelectric crystal including an FET transistor, resistors, and a capacitor forming a biasing network for said transistor; and an inductance and a second capacitor connected through said transistor; said circuit causing said crystal to vibrate and produce an alternating voltage of the crystal frequency across said inductance; should the vibration of said crystal be damped, the ''''ON'''' bias to said transistor is reduced and output voltage is reduced.
Claim 3
Dependent Claim
120 words
In a system as set forth in claim 1, an inductor coupled with said inductance receiving induced voltage, a diode rectifying said voltage to half wave D.C., a capacitor and a resistor filtering the direct current from said diode, a second transistor receiving said direct current holding it in the ''''ON'''' state; a third transistor and a resistor receiving voltage from said second transistor normally biasing said third transistor ''''OFF'''', and an indicator connected to said third transistor; should the predetermined vibration of said piezoelectric crystal be damped, ''''ON'''' bias to said second transistor is reduced and it turns to an ''''OFF'''' state whereupon said third transistor loses its ''''OFF'''' bias and turns to an ''''ON'''' state powering said indicator.
Claim 4
Dependent Claim
233 words
A detecting system including an oscillator circuit for responding to the presence and absence of a gaseous condition relative to a non-gaseous condition, comprising a piezoelectric crystal exposable to environmental gaseous and non-gaseous conditions; said crystal producing vibrations when powered; means powering said crystal to cause said crystal to vibrate including a current limiting resistor and a zener diode leading to an oscillator to provide a regulated voltage output to said oscillator circuit and said crystal; an oscillator circuit including a field effect transistor having an input side, a first output side, and a second output side; said input side being connected to said crystal output; at least one resistor and a capacitor connected to said first output side of said transistor forming a bias for said transistor; an inductance and a capacitor connected to said second output side of said transistor for receiving voltage from said crystal through said transistor; said crystal when in a gaseous condition being undamped to produce voltage to modulate said transistor bias to cause said transistor to oscillate and when in a non-gaseous condition being damped to produce unmodulated transistor bias to cause said transistor not to oscillate; the presence of voltage at said inductance thereby providing a signal indicative of a gaseous state at said crystal and the absence of voltage at said inductance thereby providing a signal indicative of a non-gaseous state at said crystal.
Claim 5
Dependent Claim
233 words
A detecting system including an oscillator circuit for responding to the presence and absence of a gaseous condition relative to a non-gaseous condition, comprising a piezoelectric crystal exposable to environmental gaseous and non-gaseous conditions; said crystal producing vibrations when powered; means powering said crystal to cause said crystal to vibrate including a current limiting resistor and a zener diode leading to an oscillator to provide a regulated voltage output to said oscillator circuit and said crystal; an oscillator circuit including a field effect transistor having an input side, a first output side, and a second output side; said input side being connected to said crystal output; at least one resistor and a capacitor connected to said first output side of said transistor forming a bias for said transistor; an inductance and a capacitor connected to said second output side of said transistor for receiving voltage from said crystal through said transistor; said crystal when in a gaseous condition being undamped to produce voltage to modulate said transistor bias to cause said transistor to oscillate and when in a non-gaseous condition being damped to produce unmodulated transistor bias to cause said transistor not to oscillate; the presence of voltage at said inductance thereby providing a signal indicative of a gaseous state at said crystal and the absence of voltage at said inductance thereby providing a signal indicative of a non-gaseous state at said crystal.
Claim 6
Dependent Claim
120 words
In a system as set forth in claim 3, an inductor coupled with said inductance receiving induced voltage, a diode rectifying said voltage to half wave D.C., a capacitor and a resistor filtering the direct current from said diode, a second transistor receiving said direct current holding it in the ''''ON'''' state; a third transistor and a resistor receiving voltage from said second transistor normally biasing said third transistor ''''OFF'''', and an indicator connected to said third transistor; should the predetermined vibration of said piezoelectric crystal be damped, ''''ON'''' bias to said second transistor is reduced and it turns to an ''''OFF'''' state whereupon said third transistor loses its ''''OFF'''' bias and turns to an ''''ON'''' state powering said indicator.
References Cited (Backward Citations)
US2932818A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |