US3733549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for measuring instantaneous frequency values
Assignee: Wandel and Golterman GmbH and Co
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Filing: 1972-04-10
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Granted: 1973-05-15
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Expires: 1992-04-10
Abstract
Abstract An incoming oscillation, whose frequency during a brief reading interval is to be determined, is converted into a first pulse train of cadence f to be compared with the cadence f'' of an astable multivibrator responsive to a stored control voltage. During the reading interval the control voltage is modified by a signal depending upon the difference of the two cadences until the same are identical; during an adjoining extended storage period, the modified control voltage keeps the multivibrator operating at the unknown cadence f which is then measured by a binary counter.
Inventors
- 👤 P Harzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:10
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
170 words
A system for measuring the frequency of an incoming oscillation existing during a brief reading interval, comprising: pulse-forming means responsive to said incoming oscillation for generating a first pulse train of a frequency f related to the frequency of said oscillation; adjustable oscillator means for generating a second pulse train of a variable frequency f''; frequency-determining means for said oscillator means; frequency-comparison means connected to said pulse-forming means and to said oscillator means for producing a control variable for said oscillator means tending to equalize said frequency f'' to said frequency f; storage means in said frequency-determining means for preserving said control variable during an extending period following said reading interval; gating means operable to connect said storage means to an output circuit of said frequency-comparison means during said reading interval for modifying said control variable in accordance with the frequency difference between said pulse trains; and pulse-counting means connected during said extended period to said oscillator means for determining said frequency f'' as a measure of said frequency f.
Claim 2
Independent Claim
170 words
A system for measuring the frequency of an incoming oscillation existing during a brief reading interval, comprising: pulse-forming means responsive to said incoming oscillation for generating a first pulse train of a frequency f related to the frequency of said oscillation; adjustable oscillator means for generating a second pulse train of a variable frequency f''; frequency-determining means for said oscillator means; frequency-comparison means connected to said pulse-forming means and to said oscillator means for producing a control variable for said oscillator means tending to equalize said frequency f'' to said frequency f; storage means in said frequency-determining means for preserving said control variable during an extending period following said reading interval; gating means operable to connect said storage means to an output circuit of said frequency-comparison means during said reading interval for modifying said control variable in accordance with the frequency difference between said pulse trains; and pulse-counting means connected during said extended period to said oscillator means for determining said frequency f'' as a measure of said frequency f.
Claim 3
Dependent Claim
36 words
A system as defined in claim 1 wherein said frequency-comparison means comprises a generator of modifying signals for said control variable responsive to the relative phasing of the pulse of said first and second pulse trains.
Claim 4
Dependent Claim
53 words
A system as defined in claim 2 wherein said oscillator means comprises an astable multivibrator provided with pulse-sharpening means for keeping constant the width of the pulses of said first pulse train, said pulse-forming means including a pulse shaper for keeping constant with the width of the pulses of said second pulse train.
Claim 5
Dependent Claim
38 words
A system as defined in claim 3, further comprising synchronizing means controlled by said gating means for periodically triggering said multivibrator from said pulse shaper to establish intermittent coincidence between pulses of said first and second pulse trains.
Claim 6
Dependent Claim
27 words
A system as defined in claim 3 wherein said generator of modifying signals comprises a difFerential flip-flop switchable only by consecutive pulses of the same pulse train.
Claim 7
Dependent Claim
25 words
A system as defined in claim 5 wherein said frequency-comparison means includes blocking means for suppressing coincident pulses from said first and second pulse trains.
Claim 8
Dependent Claim
46 words
A system as defined in claim 6 wherein said blocking means includes logical circuitry for generating a blocking signal in response to coincident pulses and an unblocking signal in response to noncoincident pulses, and a pair of pulse gates controlled by said blocking and unblocking signals.
Claim 9
Dependent Claim
49 words
A system as defined in claim 7 wherein said logical circuitry is effective to generate said blocking and unblocking signals on the trailing edges of said pulses, said blocking means further including delay means for retarding said pulses on their way from said logical circuitry to said pulse gates.
Claim 10
Dependent Claim
162 words
A system as defined in claim 2 wherein said oscillator means comprises an astable multivibrator with a main output carrying said second pulse train and with an ancillary output carrying a sawtooth wave in step with said second pulse train; said storage means comprising a first clamping circuit connected to a coarse-setting input of said multivibrator and a second clamping circuit connected to a fine-setting input of said multivibrator; said frequency-comparison means comprising a frequency discriminator connected by said gating means during said reading interval between said pulse-forming means and said first clamping circuit, for delivering to the latter a first control voltage substantially proportional to said frequency f, and circuit means controlled by said gating means and said pulse-forming means for sampling said sawtooth wave upon the occurrence of each pulse of said first pulse train for delivering to said second clamping circuit a second control voltage depending upon the phase relationship of said first pulse train and said sawtooth wave.
Claim 11
Dependent Claim
43 words
A system as defined in claim 1 wherein the operating frequency of said oscillator means is a multiple kf'' of said frequency f'', further comprising frequency-dividing means inserted between said oscillator means and said frequency-comparison means with a step-down ratio equal to k.
Claim 12
Dependent Claim
35 words
A system as defined in claim 1, further comprising integrating means connected to said oscillator means for deriving from said second pulse train a monitoring signal of a magnitude substantially proportional to said frequency f''.
References Cited (Backward Citations)
US2821702A
Cited
US3059187A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |