US3882486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable-frequency generator
Assignee: Italtel SpA
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Filing: 1973-10-09
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Granted: 1975-05-06
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Expires: 1993-10-09
Abstract
Abstract A frequency wobbler comprises a reversible binary counter to which a train of stepping pulses is continuously fed under the control of a first bistable switch applying these pulses to a forward-counting input thereof until the count surpasses a predetermined upper limit whereupon they are applied to a backward-counting input until the count drops below a predetermined lower limit, and so forth. The oscillating digital output of the counter is converted into a stepped analog voltage which is integrated, over an interval substantially smaller than a pulse-repetition period, into a sloping voltage under the control of a second bistable switch reversing its slope upon the attainment of a predetermined upper or lower level. The resulting triangular wave, varying in its fundamental frequency according to the instantaneous magnitude of the generating analog voltage, can be used to produce square or sine waves of like frequency variation.
Inventors
- 👤 Nicola Montefusco
- 👤 Alfredo Barlucchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:11
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03B; H03B23/00; H03B2200/00; H03B2200/006; H03B2200/0092
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
186 words
A system for producing a periodically and linearly varying frequency, comprising: a generator of uniformly spaced stepping pulses; a binary counter provided with a forward-counting first input and with a backward-counting second input; first bistable switch means responsive to the output of said counter for feeding said stepping pulses to said first input until the count exceeds a predetermined upper limit and to said second input until the count drops below lower predetermined dlower limit, with switchover from one to the other upon the passing of either of said limitS; a digital/analog converter connected to the output of said counter for translating said count into an alternately rising and falling stepped voltage with steps of uniform width and height; a voltage integrator having a small time constant with reference to the repetition period of said stepping pulses; and second bistable switch means for feeding said stepped voltage to said integrator with periodic polarity reversals in response to attainment of either of two predetermined voltage levels by the integrator output, thereby producing a substantially triangular wave whose frequency varies with the instantaneous magnitude of said stepped voltage.
Claim 2
Independent Claim
186 words
A system for producing a periodically and linearly varying frequency, comprising: a generator of uniformly spaced stepping pulses; a binary counter provided with a forward-counting first input and with a backward-counting second input; first bistable switch means responsive to the output of said counter for feeding said stepping pulses to said first input until the count exceeds a predetermined upper limit and to said second input until the count drops below lower predetermined dlower limit, with switchover from one to the other upon the passing of either of said limitS; a digital/analog converter connected to the output of said counter for translating said count into an alternately rising and falling stepped voltage with steps of uniform width and height; a voltage integrator having a small time constant with reference to the repetition period of said stepping pulses; and second bistable switch means for feeding said stepped voltage to said integrator with periodic polarity reversals in response to attainment of either of two predetermined voltage levels by the integrator output, thereby producing a substantially triangular wave whose frequency varies with the instantaneous magnitude of said stepped voltage.
Claim 3
Dependent Claim
106 words
A system as defined in claim 1 wherein each of said bistable switch means comprises a flip-flop with a setting input and a resetting input, a first voltage comparator working into said setting input, and a second voltage comparator working into said resetting input; the comparators of said first switch means having each one input connected to the counter output and another input connected to a first and a second source of reference potential respectively; the comparators of said second switch means having each one input connected to the integrator output and another input connected to a third and a fourth source of reference potential, respectively.
Claim 4
Dependent Claim
22 words
A system as defined in claim 2 wherein said sources of reference potential are adjustable for varying said limits and said levels.
Claim 5
Dependent Claim
23 words
A system as defined in claim 3, further comprising indicator means for the frequency of said triangular wave connected to the integrator output.
Claim 6
Dependent Claim
33 words
A system as defined in claim 4, further comprising selector means operable to feed the potentials of said first and second sources to said second switch means in lieu of said stepped voltage.
Claim 7
Dependent Claim
27 words
A system as defined in claim 1, further comprising harmonics-suppressor means connected to the integrator output for deriving a substantially sinusoidal wave from said substantially triangular wave.
Claim 8
Dependent Claim
31 words
A system as defined in claim 1 wherein said second switch means is provided with an ancillary output for delivering a square wave at the frequency of said substantially triangular wave.
Claim 9
Dependent Claim
40 words
A system as defined in claim 1 wherein said generator comprises a fixed-frequency oscillator and frequency-divider means connected to said oscillator for producing said stepping pulses, said frequency-divider means being adjustable to vary the repetition frequency of said stepping pulses.
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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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |