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US3670765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level sensor incorporating pulse techniques
Assignee: Individual
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Filing: 1970-07-27
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Granted: 1972-06-20
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Expires: 1990-07-27
Abstract
Abstract A system is disclosed for sensing levels of electricallyconductive liquid by utilizing the liquid as a switch in cooperation with electrical probes. The destructive effects of liquid conduction on the probe are avoided by the use of pulse techniques. A pulse generator operates when the liquid under observation attains a probe-contact level to complete an electrical circuit. The pulse generator is disclosed in the form of a relaxation oscillator which pulses a trigger circuit, the output of which is integrated to provide a control signal. A plural-probe system is also disclosed. The pulses provided from the pulse generator have an interval of not more than one fifth of the interval therebetween.
Inventors
- 👤 Joel E Haynes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:36
CPC Classifications
G; G05; G05D; G05D9/00; G05D9/12; G01; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/241; G01F23/243; G01F23/244; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7306
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
115 words
A liquid control system for use, as to maintain predetermined levels of an electrically-conductive liquid in a vessel, or the like, as by regulating a liquid flow means, comprising: at least one probe means for engaging said liquid in said vessel at a predetermined level thereof to thereby provide a closed circuit path through said liquid; oscillation means for generating pulses of relatively low duty cycle, said oscillation means defining an open circuit which inhibits the operation of said oscillation means; means connecting said closed circuit path through said liquid across said open circuit defined by said oscillation means; and means for sensing operations of said oscillation means to thereby control said liquid flow means.
Claim 2
Dependent Claim
115 words
A liquid control system for use, as to maintain predetermined levels of an electrically-conductive liquid in a vessel, or the like, as by regulating a liquid flow means, comprising: at least one probe means for engaging said liquid in said vessel at a predetermined level thereof to thereby provide a closed circuit path through said liquid; oscillation means for generating pulses of relatively low duty cycle, said oscillation means defining an open circuit which inhibits the operation of said oscillation means; means connecting said closed circuit path through said liquid across said open circuit defined by said oscillation means; and means for sensing operations of said oscillation means to thereby control said liquid flow means.
Claim 3
Dependent Claim
21 words
A system according to claim 1 wherein said oscillator means includes a reactance and a resistor and comprises a relaxation oscillator.
Claim 4
Dependent Claim
27 words
A system according to claim 1 wherein the duty cycle of said oscillator provides pulses of an interval of not more than one-fifth of the interval therebetween.
Claim 5
Dependent Claim
26 words
A system according to claim 1 wherein said means for connecting said oscillator means includes an integrator means to provide a continuous signal from said pulses.
Claim 6
Dependent Claim
115 words
A system according to claim 1 wherein said probe means comprises a first probe circuit and a second probe circuit defining different levels in said vessel; and wherein said oscillation means includes a pair of said oscillator means; and wherein said means connecting includes a pair of connecting circuits for connecting said first probe circuit across the open circuit defined by one of said oscillator means and for connecting said second probe circuit across the open circuit of another of said oscillator means; and wherein said means for connecting includes logic means connected to said pair of oscillator means to control said flow means in relation to each of said different levels in said vessel.
Claim 7
Dependent Claim
30 words
A liquid control system according to claim 1 wherein said means for sensing includes a trigger circuit means to substantially increase the duty cycle of pulses from said oscillator means.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |