US3704431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coulometer controlled variable frequency generator
Assignee: Curtis Instruments Inc
•
Filing: 1971-07-21
•
Granted: 1972-11-28
•
Expires: 1991-07-21
Abstract
Abstract A variable frequency generator utilizing a coulometer for generating a signal having an amplitude that varies in accordance with the integral of a selected function. A DC current source and a variable frequency interrogation oscillator are connected to the input terminals of a coulometer which modulates the output of the oscillator in accordance with the integral of the current from the current source. The output of the coulometer is amplified by an AC amplifier and is then demodulated by a standard envelope detector. The demodulated signal is fed back to the oscillator to proportionally control the frequency of the oscillator, that is, as the amplitude of the modulated signal increases, the frequency of the oscillator increases and, as the amplitude of the demodulated signal decreases, the frequency of the oscillator decreases.
Inventors
- 👤 Eugene P Finger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:35
CPC Classifications
G; G01; G01R; G01R22/00; G01R22/02; H; H03; H03B; H03B23/00; H03B2200/00; H03B2200/006; H03B2200/0092
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
A variable frequency generator comprising means for generating an AC signal, means for generating an electric current function, means for modulating said AC signal by the integral of said current function, means for demodulating said modulated signal, said demodulated signal having an amplitude that is proportional to the envelope of said AC signal multiplied by the integral of said current function, and feedback means for varying the frequency of said AC signal in accordance with said demodulated signal.
Claim 2
Dependent Claim
78 words
A variable frequency generator comprising means for generating an AC signal, means for generating an electric current function, means for modulating said AC signal by the integral of said current function, means for demodulating said modulated signal, said demodulated signal having an amplitude that is proportional to the envelope of said AC signal multiplied by the integral of said current function, and feedback means for varying the frequency of said AC signal in accordance with said demodulated signal.
Claim 3
Dependent Claim
17 words
The generator of claim 1 wherein said means for modulating said AC signal compRises a capacitive coulometer.
Claim 4
Dependent Claim
49 words
The circuit of claim 2 wherein said coulometer comprises an output capacitance, means for varying said output capacitance in accordance with the integral of said current function, means for connecting said AC signal generating means to said coulometer, and means for detecting said AC signal across said output capacitance.
Claim 5
Dependent Claim
50 words
The generator of claim 3 wherein said means for varying the frequency of said AC signal includes feedback means for connecting the output of said demodulating means to AC signal generating means, said AC signal generating means generating a signal having a frequency that varies proportionately as the demodulated signal.
Claim 6
Independent Claim
67 words
A method of generating a variable frequency signal comprising the steps of generating an electrical function, modulating an AC signal in accordance with the integral of said current function, demodulating said modulated signal to provide a waveform having an amplitude proportional to the integral of said current function multiplied by said AC signal, and varying the frequency of said AC signal in accordance with said demodulated signal.
Claim 7
Independent Claim
67 words
A method of generating a variable frequency signal comprising the steps of generating an electrical function, modulating an AC signal in accordance with the integral of said current function, demodulating said modulated signal to provide a waveform having an amplitude proportional to the integral of said current function multiplied by said AC signal, and varying the frequency of said AC signal in accordance with said demodulated signal.
Claim 8
Dependent Claim
44 words
The method of claim 5 wherein said step for modulating said AC signal in accordance with the integral of said current function comprises the steps of deriving the integral of said current function and modulating said AC signal by the integral of said current.
References Cited (Backward Citations)
US3255413A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-28 | 1976-05-29 | 1976-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-28 | 1980-05-29 | 1980-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-28 | 1984-05-29 | 1984-11-28 | $7700.00 | Window Closed / Lapsed |