US3798564A
Expired / Lapsed
US
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Digital frequency multiplier
Assignee: Individual
•
Filing: 1972-04-18
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Granted: 1974-03-19
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Expires: 1992-04-18
Abstract
Abstract A plural oscillator system with all the characteristics of an analog or variable frequency oscillator, but with the added capability of locking digitally to any frequency within its range. The system has two modes of operation, unlocked and locked. In the unlocked mode, the system employs a variable frequency oscillator together with a reference oscillator and counter to produce the system output and to log the period of the variable frequency oscillator into a memory. In the locked mode, the contents of the memory are held constant, and the variable frequency oscillator no longer drives the system output. Instead, the reference oscillator and counter are used in conjunction with a digital comparator to produce the system output with a frequency determined by the contents of the memory. Thus, the system in the locked mode operates as a digital oscillator at the frequency that the variable frequency oscillator operated before the mode change.
Inventors
- 👤 J Langham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:52
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/60; G06F7/68
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
157 words
Apparatus for frequency mUltiplying an input signal comprising sampling means responsive to said input signal and including a first source of a reference frequency signal for determining a first signal representative of the instantaneous period of the input signal, and generating and comparing means for presenting an output signal and including a second source of a reference frequency signal for determining a second signal representative of the instantaneous period of the output signal, said generating and comparing means connected in open-loop relation to the sampling means and responsive to the said first signal from said sampling means for comparing the same with said second signal and generating an output signal at a frequency that is a linear function of the frequency of the input signal, said linear function being the ratio of the frequency of the reference frequency signal from said generating and comparing means to the frequency of the reference frequency signal of said sampling means.
Claim 2
Dependent Claim
157 words
Apparatus for frequency mUltiplying an input signal comprising sampling means responsive to said input signal and including a first source of a reference frequency signal for determining a first signal representative of the instantaneous period of the input signal, and generating and comparing means for presenting an output signal and including a second source of a reference frequency signal for determining a second signal representative of the instantaneous period of the output signal, said generating and comparing means connected in open-loop relation to the sampling means and responsive to the said first signal from said sampling means for comparing the same with said second signal and generating an output signal at a frequency that is a linear function of the frequency of the input signal, said linear function being the ratio of the frequency of the reference frequency signal from said generating and comparing means to the frequency of the reference frequency signal of said sampling means.
Claim 3
Dependent Claim
171 words
Apparatus as defined in claim 1 and wherein said sampling means includes a first resettable accumulator connected to said first source and operable in response to said input signal to repeatedly produce said first signal representative of the instantaneous period of said input signal, a memory operable to store and present an updated signal corresponding to said first signal, and an input buffer connected to actuate the memory to receive said first signal and to reset said first resettable accumulator and wherein said generating and comparing means includes a second resettable accumulator connected to said second source and operable to repeatedly produce said second signal representative of the instantaneous period of the output signal, a comparator responsive to the second resettable accumulator and to the updated signal from the memory to produce the output signal when said second signal equals the updated signal of the memory, and an output buffer responsive to the comparator to present the output signal and to connect the output signal to reset the second resettable accumulator.
Claim 4
Dependent Claim
131 words
Apparatus as defined in claim 1 and including a second generating and comparing means for presenting a second output signal and including a third source of a reference frequency signal for presenting a third signal representative of the instantaneous period of the second output signal, said generating and comparing means connected in open-loop relation to the sampling means and responsive to the said first signal presented by said sampling means for comparing the same with said third signal and generating an output signal at a frequency that is a linear function of the frequency of the input signal, said linear function being the ratio of the frequency of the reference frequency signal of said second generating and comparing means to the frequency of the reference frequency signal of said sampling means.
Claim 5
Dependent Claim
62 words
Apparatus as defined in claim 1 and wherein said sampling means includes a memory and a mode selector buffer operable in a first mode to connect the input signal to repeatedly update the memory to store a count representative of the instantaneous period of said input signal and operable in a second mode to retain the count last stored in the memory.
Claim 6
Dependent Claim
71 words
Apparatus as defined in claim 2 and wherein said input buffer is a mode selector buffer operable in a first mode to connect the input signal to repeatedly update the memory of said sampling means to store a count representative of the instantaneous period of said input signal and operable in a second mode to retain the count last stored in said memory while the operation of said comparator is continued.
References Cited (Backward Citations)
US3484712A
Cited
US3670255A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |