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Patent US3701951A successfully refreshed from Google Patents.
US3701951A
Expired / Lapsed
US
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Digital indicator for use with tunable electronic apparatus
Assignee: Emerson Electric Co
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Filing: 1971-01-05
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Granted: 1972-10-31
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Expires: 1991-01-05
Abstract
Abstract A digital tuning indicator for use with tunable electronic apparatus such as FM multiplex receivers includes a harmonic generator which produces a multitude of RF voltages corresponding, respectively, to the frequencies to which the device may be tuned over the frequency band of interest. A mixer or beat generator is responsive to the variable frequency output of the local RF oscillator of the receiver and the harmonic corresponding to the frequency to which the receiver is tuned. A pulse generator coupled to the output of the beat generator produces a pulse when the frequency to which the receiver is tuned approaches the frequency of a station within the frequency band. These pulses are counted by a digital counter which is calibrated to provide a visual indication of the frequency of the station to which the receiver is tuned.
Inventors
- 👤 Friedrich Johann Krausser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:35
CPC Classifications
H; H03; H03J; H03J1/00; H03J1/02; H03J1/04; H03J1/045; H03J1/047; H03J1/048; H03J5/00; H03J5/02; H03J5/0245
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
260 words
A digital tuning indicator for use with electronic apparatus which is tunable over a preselected frequency band, the carrier frequencies of said band being spaced by at least N cycles per second, said apparatus including a voltage variable capacitor for tuning the apparatus to a selected one of said frequencies in response to a variable voltage, comprising an oscillator having an output frequency of K cycles per second, a harmonic generator responsive to said oscillator for producing harmonics spaced N cycles per second apart throughout said band, a beat generator, harmonic selector means for coupling the harmonic corresponding to the frequency to which the apparatus is tuned to an input of said beat generator when the apparatus is tuned to one of said carrier frequencies, means for coupling a variable frequency signal to another input of said beat generator, the frequency of said variable frequency signal corresponding to the frequency to which said apparatus is tuned, said beat generator producing a signal having a frequency equal to the frequency difference between the input signals applied thereto, means responsive to the output of said beat generator for producing a pulse when said frequency difference is less than a preselected amount, digital counter means for counting said pulses, said counter means being calibrated to provide a visual indication of the frequency to which said apparatus is tuned, and means for resetting said counter when said tuning voltage swiTches from a voltage corresponding to the high end of the frequency band to a voltage corresponding to the low end of said frequency band.
Claim 2
Dependent Claim
260 words
A digital tuning indicator for use with electronic apparatus which is tunable over a preselected frequency band, the carrier frequencies of said band being spaced by at least N cycles per second, said apparatus including a voltage variable capacitor for tuning the apparatus to a selected one of said frequencies in response to a variable voltage, comprising an oscillator having an output frequency of K cycles per second, a harmonic generator responsive to said oscillator for producing harmonics spaced N cycles per second apart throughout said band, a beat generator, harmonic selector means for coupling the harmonic corresponding to the frequency to which the apparatus is tuned to an input of said beat generator when the apparatus is tuned to one of said carrier frequencies, means for coupling a variable frequency signal to another input of said beat generator, the frequency of said variable frequency signal corresponding to the frequency to which said apparatus is tuned, said beat generator producing a signal having a frequency equal to the frequency difference between the input signals applied thereto, means responsive to the output of said beat generator for producing a pulse when said frequency difference is less than a preselected amount, digital counter means for counting said pulses, said counter means being calibrated to provide a visual indication of the frequency to which said apparatus is tuned, and means for resetting said counter when said tuning voltage swiTches from a voltage corresponding to the high end of the frequency band to a voltage corresponding to the low end of said frequency band.
Claim 3
Dependent Claim
48 words
A digital tuning indicator according to claim 1, including means for producing a voltage having a preselected frequency corresponding to the lowest frequency to be indicated, and means for coupling said voltage in place of said selected harmonic to said beat generator after said counter has been reset.
Claim 4
Dependent Claim
41 words
A digital tuning indicator according to claim 1, wherein said harmonic selector means also includes a voltage-variable capacitor connected in parallel with an inductance to provide a tunable tank circuit, and means for applying said tuning voltage across said tank circuit.
Claim 5
Dependent Claim
34 words
A digital tuning indicator according to claim 3, wherein said pulse generator means includes a low-pass filter for producing an output when said frequency difference is equal to or less than said preselected amount.
Claim 6
Dependent Claim
34 words
A digital tuning indicator according to claim 2, wherein said pulse generator means includes a low-pass filter for producing an output when said frequency difference is equal to or less than said preselected amount.
Claim 7
Dependent Claim
248 words
A digital tuning indicator for use with electronic apparatus which is tunable over a preselected frequency band, said apparatus including tuner means for tuning the apparatus to one of a selected number of frequencies within said band, means for producing a plurality of signals having respective frequencies equal to said selected frequencies, a beat generator, means for coupling the signal having a frequency corresponding to the frequency to which the apparatus is tuned to an input of said beat generator when said apparatus is tuned to one of said selected frequencies, means for coupling a variable frequency signal to another input of said beat generator, the frequency of said variable frequency signal corresponding to the frequency to which said apparatus is tuned, said beat generator producing a signal having a frequency equal to the frequency difference between the input signals applied thereto, means responsive to the output of said beat generator for producing a pulse when said frequency difference is reduced to a preselected amount, digital counter means for counting said pulses, said counter means being calibrated to provide a visual indication of the frequency to which said apparatus is tuned, means for resetting said counter after the apparatus is tuned to the lowest frequency in said band, means for producing a voltage having a preselected frequency corresponding to the lowest frequency to be indicated, and means for coupling said voltage in place of said frequency corresponding signal to said beat generator after said counter has been reset.
Claim 8
Dependent Claim
248 words
A digital tuning indicator for use with electronic apparatus which is tunable over a preselected frequency band, said apparatus including tuner means for tuning the apparatus to one of a selected number of frequencies within said band, means for producing a plurality of signals having respective frequencies equal to said selected frequencies, a beat generator, means for coupling the signal having a frequency corresponding to the frequency to which the apparatus is tuned to an input of said beat generator when said apparatus is tuned to one of said selected frequencies, means for coupling a variable frequency signal to another input of said beat generator, the frequency of said variable frequency signal corresponding to the frequency to which said apparatus is tuned, said beat generator producing a signal having a frequency equal to the frequency difference between the input signals applied thereto, means responsive to the output of said beat generator for producing a pulse when said frequency difference is reduced to a preselected amount, digital counter means for counting said pulses, said counter means being calibrated to provide a visual indication of the frequency to which said apparatus is tuned, means for resetting said counter after the apparatus is tuned to the lowest frequency in said band, means for producing a voltage having a preselected frequency corresponding to the lowest frequency to be indicated, and means for coupling said voltage in place of said frequency corresponding signal to said beat generator after said counter has been reset.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |