Patent US3689849A successfully refreshed from Google Patents.
US3689849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal generator
Assignee: Instruments for Research and Industry I2R Inc
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Filing: 1971-07-21
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Granted: 1972-09-05
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Expires: 1991-07-21
Abstract
Abstract A signal generator whose output is selected and controlled by digital circuitry consisting of a frequency selector, a reference frequency generator for producing a stable fixed frequency, a multi-stage binary counter/divider connected to the output of the reference frequency generator, a counter connected to the output of the frequency selector and the reference frequency generator for producing the nine''s compliment of the selected frequency, a multi-stage binary counter/register connected to the output of the counter, a multi-stage ''''AND'''' gate circuit coupled to the outputs of the counter/divider and the counter/register to permit selected ''''AND'''' gates to be enabled to produce a selected frequency, and a multi-stage digital/analog converter controlled by the counter/register. The analog voltage thus produced is combined with a correction voltage derived from a digital/analog converter controlled by a reversing counter which compares the selected frequency with the output frequency. The combination of voltages is servoed to that voltage that minimizes the difference between the selected frequency and the output frequency on a cycle-for-cycle basis.
Inventors
- 👤 Elston H Swanson
- 👤 James D Fahnestock
- 👤 William H Wicks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:07
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/181
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
148 words
A signal generator comprising; frequency selector means, a reference frequency generator for producing a stable fixed frequency FR, a multi-stage binary counter/divider connected to the output of said reference frequency generator, counter means connected to the output of said frequency selector means and said reference frequency generator for producing the nine''s complement of the selected frequency, a multi-stage binary counter/register connected to the output of said counter means, a multi-stage ''''AND'''' gate circuit coupled to the outputs of said counter/divider and said counter/register to permit selected ''''AND'''' gates to be enabled to produce a selected frequency Fs, a multi-stage digital/analog converter connected to the output of said multi-stage binary counter-register, and means for combining the output of said digital/analog converter and a correction voltage derived from a cycle-by-cycle digital comparison of the output frequency and the selected frequency Fs to produce the output frequency Fo of the generator.
Claim 2
Dependent Claim
148 words
A signal generator comprising; frequency selector means, a reference frequency generator for producing a stable fixed frequency FR, a multi-stage binary counter/divider connected to the output of said reference frequency generator, counter means connected to the output of said frequency selector means and said reference frequency generator for producing the nine''s complement of the selected frequency, a multi-stage binary counter/register connected to the output of said counter means, a multi-stage ''''AND'''' gate circuit coupled to the outputs of said counter/divider and said counter/register to permit selected ''''AND'''' gates to be enabled to produce a selected frequency Fs, a multi-stage digital/analog converter connected to the output of said multi-stage binary counter-register, and means for combining the output of said digital/analog converter and a correction voltage derived from a cycle-by-cycle digital comparison of the output frequency and the selected frequency Fs to produce the output frequency Fo of the generator.
Claim 3
Dependent Claim
17 words
The signal generator as recited in claim 1, wherein said frequency selector means comprises a digital keyboard.
Claim 4
Dependent Claim
98 words
The signal generator as recited in claim 1, wherein said means for combining comprises a reversing counter having one input coupled to the selected frequency Fs and its other input coupled to the output frequency Fo, a second digital/analog converter for producing a correction voltage proportional to the difference between the output frequency and the selected frequency, a summing amplifier for combining the output of said first and second digital/analog converters, and a voltage controlled oscillator coupled to the output of said summing amplifier for producing the output frequency proportional to the magnitude of the summing amplifier output.
Claim 5
Dependent Claim
63 words
The signal generator as recited in claim 3, wherein said voltage controlled oscillator comprises a fixed frequency oscillator, and a voltage variable oscillator having its input coupled to said summing amplifier, and a mixer connected to the outputs of both of said oscillators to produce the output frequency Fo equal to the difference frequency between the fixed frequency and the voltage variable oscillators.
Claim 6
Dependent Claim
62 words
The signal generator as recited in claim 4, wherein said voltage controlled oscillator additionally comprises integrator means coupled to the output of said summing amplifier and an input of said summing amplifier to gradually integrate the output of said summing amplifier coupling to said voltage variable oscillator as the magnitude of the signal excursions on the input of said summing amplifier subside.
Claim 7
Dependent Claim
38 words
The signal generator as recited in claim 1 comprising an indicator counter/register coupled to the output of said counter means, and a decimal indicator connected to the output of said indicator counter/register for displaying the output frequency selected.
Claim 8
Dependent Claim
71 words
The signal generator as recited in claim 3 additionally comprising frequency range selection means, a first frequency divider coupled to the output of said range selection means and the selected frequency Fs for dividing Fs at one input of said reversing counter, and a second frequency divider coupled to the output of said range selection means and the output frequency Fo for dividing Fo at another input of said reversing counter.
Claim 9
Dependent Claim
48 words
The signal generator as recited in claim 6 additionally comprising an external input connection, and counter control circuitry coupled to said external input, and switch means for activating said control circuitry to permit external frequencies applied to said external input connection to be displayed on said decimal indicator.
Claim 10
Dependent Claim
41 words
The signal generator as recited in claim 1 additionally comprising a sweep function control oscillator and a switch for coupling said control oscillator to said multi-stage binary counter/register so that said oscillator will sweep between preselected upper and lower frequency limits.
References Cited (Backward Citations)
US3364439A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |