US4177434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant amplitude control of electromechanical oscillators
Assignee: EIDP Inc
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Filing: 1978-05-30
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Granted: 1979-12-04
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Expires: 1998-05-30
Abstract
Abstract Method and system for the constant amplitude control of an electromechanical oscillator utilizing a phase locked oscillator to generate a secondary a-c setpoint which is compared to the oscillator output to provide a difference signal which is passed as a fast-acting negative feedback signal to stabilize the amplitude.
Inventors
- 👤 Edward S. Ida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:33
CPC Classifications
H; H03; H03L; H03L5/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
134 words
A method for maintaining the amplitude of an electromechanical oscillator mechanical output signal constant independent of its operating frequency, comprising the steps of: generating a constant amplitude a-c signal in phase agreement with said output signal; developing a d-c signal related to said output signal amplitude; continuously integrating the difference in voltages between said d-c signal and a preselected setpoint voltage value to provide a control signal; amplitude modulating said constant amplitude a-c signal with said control signal to provide a modulated a-c signal in phase with said output signal to maintain said oscillator in oscillation; and maintaining the amplitude of said output signal in accordance with the algebraic sum of a linear negative feedback signal derived from said output signal and said modulated a-c signal, thereby to maintain said output signal amplitude constant.
Claim 2
Independent Claim
134 words
A method for maintaining the amplitude of an electromechanical oscillator mechanical output signal constant independent of its operating frequency, comprising the steps of: generating a constant amplitude a-c signal in phase agreement with said output signal; developing a d-c signal related to said output signal amplitude; continuously integrating the difference in voltages between said d-c signal and a preselected setpoint voltage value to provide a control signal; amplitude modulating said constant amplitude a-c signal with said control signal to provide a modulated a-c signal in phase with said output signal to maintain said oscillator in oscillation; and maintaining the amplitude of said output signal in accordance with the algebraic sum of a linear negative feedback signal derived from said output signal and said modulated a-c signal, thereby to maintain said output signal amplitude constant.
Claim 3
Dependent Claim
185 words
An electromechanical oscillatory system providing a constant amplitude mechanical output signal independent of its operating frequency, said system having an input drive and an output and comprising: a phase-locked loop circuit connected to the output of said system generating a constant amplitude a-c signal; an amplitude detector coupled to the output of said system producing a time-varying d-c signal tracking said output signal; an integrator connected to the output of said detector integrating the difference between said time-varying d-c signal and a preselected setpoint signal; a modulator means connected to the output terminal of said integrator for modulating said a-c signal as a function of the magnitude of said integrated d-c signal to provide a modulated a-c signal in phase with said output signal to maintain said oscillator in oscillation; and a summing junction coupled to the outputs of said system for summing a linear negative feedback signal derived from said output and said modulator means to provide a drive control signal as feedback to said system in accordance with the magnitude of the difference between said modulated a-c signal and said negative feedback signal.
Claim 4
Dependent Claim
185 words
An electromechanical oscillatory system providing a constant amplitude mechanical output signal independent of its operating frequency, said system having an input drive and an output and comprising: a phase-locked loop circuit connected to the output of said system generating a constant amplitude a-c signal; an amplitude detector coupled to the output of said system producing a time-varying d-c signal tracking said output signal; an integrator connected to the output of said detector integrating the difference between said time-varying d-c signal and a preselected setpoint signal; a modulator means connected to the output terminal of said integrator for modulating said a-c signal as a function of the magnitude of said integrated d-c signal to provide a modulated a-c signal in phase with said output signal to maintain said oscillator in oscillation; and a summing junction coupled to the outputs of said system for summing a linear negative feedback signal derived from said output and said modulator means to provide a drive control signal as feedback to said system in accordance with the magnitude of the difference between said modulated a-c signal and said negative feedback signal.
Claim 5
Dependent Claim
27 words
The system of claim 2 wherein said system is a torsional oscillatory viscometer probe and includes attenuator means for adjusting the amplitude of oscillation of said probe.
Claim 6
Dependent Claim
13 words
The system of claim 2 wherein said modulator means is a photo conductor.
Claim 7
Dependent Claim
21 words
The system of claim 2 wherein said detector comprises a low-pass filter circuit connected in series with a precision a-c detector.
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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) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |