US3883811A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Densitometer
Assignee: TDK Micronas GmbH
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Filing: 1974-08-12
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Granted: 1975-05-13
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Expires: 1994-08-12
Abstract
Abstract A vibration densitometer including a closed loop electromechanical oscillator for vibrating a fluid immersible vane. A digital output directly proportional to density is achieved through a unique digital squarer. The densitometer is an all digital system. In the loop, a tracking filter is provided. Separate search and track automatic gain control feedbacks are provided. A threshold detector controls clamps and a gate to cause the voltage controlled oscillator of a first phase lock loop to search or track the vane resonant frequency. The threshold detector also effects the search feedback. A phase adjustment circuit and a second phase lock loop are employed to impress a sine wave voltage component on the vane driver of a phase which creates maximum efficiency.
Inventors
- 👤 Gerald Lance Schlatter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:21
CPC Classifications
G; G01; G01N; G01N9/00; G01N9/002; H; H03; H03L; H03L7/00; H03L7/06; G01N2009/008
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
189 words
Apparatus for producing a sine wave signal manually adjustable in phase, said apparatus comprising: a phase adjustment circuit having input and output leads; first means having an output lead connected to said circuit input lead and actuable to produce a saw-tooth signal having ramps, said first means being actuable to impress said saw-tooth signal repeatedly at a predetermined fundamental frequency on said circuit input lead, the rate of change of the magnitude of said signal with respect to time being constant during actuating portions of said signal during which said ramps are generated, said circuit including adjustment means to cause a pulse to be impressed upon said circuit output lead each time the magnitude of said ramp becomes equal to a predetermined magnitude, said predetermined magnitude being adjustable with said adjustment means; a phase lock loop having input and output leads; and second means connecting said circuit output lead to said phase lock loop input lead, said phase lock loop producing a sine wave signal on said output lead thereof of said predetermined fundamental frequency and of a phase adjustable in accordance with the adjustment of said adjustment means.
Claim 2
Dependent Claim
189 words
Apparatus for producing a sine wave signal manually adjustable in phase, said apparatus comprising: a phase adjustment circuit having input and output leads; first means having an output lead connected to said circuit input lead and actuable to produce a saw-tooth signal having ramps, said first means being actuable to impress said saw-tooth signal repeatedly at a predetermined fundamental frequency on said circuit input lead, the rate of change of the magnitude of said signal with respect to time being constant during actuating portions of said signal during which said ramps are generated, said circuit including adjustment means to cause a pulse to be impressed upon said circuit output lead each time the magnitude of said ramp becomes equal to a predetermined magnitude, said predetermined magnitude being adjustable with said adjustment means; a phase lock loop having input and output leads; and second means connecting said circuit output lead to said phase lock loop input lead, said phase lock loop producing a sine wave signal on said output lead thereof of said predetermined fundamental frequency and of a phase adjustable in accordance with the adjustment of said adjustment means.
Claim 3
Dependent Claim
30 words
The invention as defined in claim 1, wherein said saw-tooth signal is a saw-tooth voltage, said pulse being a voltage pulse, said sine wave signal being a sine wave voltage.
Claim 4
Dependent Claim
159 words
The invention as defined in claim 2, wherein said phase adjustment circuit includes first and second voltage dividers each having an intermediate tap, a potentiometer having a winding with first and second ends, and a wiper, first and second differential amplifiers each having inverting and non-inverting inputs, and an output, said wiper being connected to the inverting input of said first amplifier, the tap of said first divider being connected to the non-inverting input of said first amplifier, a resistor having one end connected from the output of said first amplifier, said second amplifier output being connected to said first amplifier output, the inverting input of said second amplifier being connected from said second divider tap, a square wave voltage source having an output lead and impressing a square wave on said second amplifier non-inverting input of said predetermined frequency and in phase with said saw-tooTh voltage, said first means impressing said saw-tooth voltage on said first divider tap.
Claim 5
Dependent Claim
70 words
The invention as defined in claim 3, wherein means are provided to maintain the opposite ends of each of said dividers and the opposite ends of said potentiometer at two different respective D.C. potentials, means to maintain the other end of said resistor at a potential different from one of said two potentials, a capacitor being connected from the output lead of said first means to said first divider tap.
References Cited (Backward Citations)
US2545346A
Cited
US2645717A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |