US3743943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for supplying a tuning voltage to an electronically tuned fm radio receiver from the oscillator of an am radio receiver
Assignee: Motors Liquidation Co
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Filing: 1971-12-22
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Granted: 1973-07-03
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Expires: 1991-12-22
Abstract
Abstract The output of a local oscillator of an AM radio receiver tunable from a frequency f1 to a higher frequency f2 is supplied to a pulse generator which generates a pulse having constant width and constant amplitude for each cycle of the output of the AM oscillator. The output of the pulse generator is a series of pulses which is supplied to a first converter which generates a unidirectional signal at its output which is equal to a constant K/2 times the frequency f of the series of pulses. The series of pulses is also supplied to a second converter which generates a signal at its output equal to - K/2 times the frequency f of the series of pulses plus a constant Z. The expression for the magnitude of the potential between the outputs of the first and second converters is Kf - Z, where K and Z are determined by the simultaneous solution of the equations A Kf1 - Z and B Kf2 Z, and A/B is the required tuning voltage ratio required for tuning a voltage tuned FM receiver over the entire FM frequency band.
Inventors
- 👤 J Mason
- 👤 J Mckibben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:12
CPC Classifications
H; H03; H03J; H03J3/00; H03J3/02; H03J3/16; H03J3/18; H03J3/185
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
272 words
A circuit for supplying a tuning voltage to an electronically tuned FM radio receiver tunable over the FM frequency band in response to a tuning voltage having a low to high voltage ratio A/B comprising, in combination, an AM receiver having an AM local oscillator tunable to a frequency f which varies from a low frequency f1 to a high frequency f2, the ratio f1/f2 being different from the ratio A/B; circuit means connected to the AM local oscillator, the circuit means including a first converter responsive to the tuned frequency f of the AM local oscillator for generating a signal having a first polarity at a first output terminal, the signal having a magnitude defined by the expression K/2 f, 1 where K is a constant and a second converter responsive to the tuned frequency f of the local oscillator for generating a signal having a second polarity opposite the first polarity at a second output terminal, the signal having a magnitude defined by the expression (K/2) f - Z 2 where Z is a constant, the magnitude of the potential between the first and second outPut terminals being defined by the expression Kf - Z, 3 the magnitudes of K and Z being determined by the equations A Kf1 - Z 4 and B Kf2 - Z; 5 and means connected to the first and second output terminals for supplying the potential therebetween to the electronically tuned FM radio receiver to effect tuning thereof, whereby the potential between the first and second output terminals varies from A to B as the AM local oscillator is tuned from f1 to f2.
Claim 2
Dependent Claim
272 words
A circuit for supplying a tuning voltage to an electronically tuned FM radio receiver tunable over the FM frequency band in response to a tuning voltage having a low to high voltage ratio A/B comprising, in combination, an AM receiver having an AM local oscillator tunable to a frequency f which varies from a low frequency f1 to a high frequency f2, the ratio f1/f2 being different from the ratio A/B; circuit means connected to the AM local oscillator, the circuit means including a first converter responsive to the tuned frequency f of the AM local oscillator for generating a signal having a first polarity at a first output terminal, the signal having a magnitude defined by the expression K/2 f, 1 where K is a constant and a second converter responsive to the tuned frequency f of the local oscillator for generating a signal having a second polarity opposite the first polarity at a second output terminal, the signal having a magnitude defined by the expression (K/2) f - Z 2 where Z is a constant, the magnitude of the potential between the first and second outPut terminals being defined by the expression Kf - Z, 3 the magnitudes of K and Z being determined by the equations A Kf1 - Z 4 and B Kf2 - Z; 5 and means connected to the first and second output terminals for supplying the potential therebetween to the electronically tuned FM radio receiver to effect tuning thereof, whereby the potential between the first and second output terminals varies from A to B as the AM local oscillator is tuned from f1 to f2.
Claim 3
Dependent Claim
271 words
In combination: an FM radio receiver tunable over the FM frequency band in response to the magnitude of a tuning voltage V having a low-to-high magnitude ratio A/B; an AM receiver including an AM local oscillator having a frequency f which varies from a low frequency f1 to a high frequency f 2 as the AM radio receiver is tuned across the AM band thereby to provide a low-to-high frequency ratio f1/f2 different from the ratio A/B; a pulse generator connected to the AM local oscillator for generating constant amplitude and constant width tuning pulses having the frequency f; a first converter connected to the pulse generator for generating a positive signal O1 at a first output terminal, the signal being defined by the expression O1 (K/2) f 1 where K is a constant; a second converter connected to the pulse generator for generating a negative signal O2 at a second output terminal, the signal being defined by the expression O2 -((K/2) f - Z) 2 where Z is a constant, the potential between the first and second output terminals being the tuning voltage V defined by the expression V O1 - O2 3 so that V Kf - Z, 4 where the magnitudes of K and Z are determined by the equations A Kf1 - Z 5 and B Kf2 - Z; 6 and means connected to the first and second output terminals for applying the tuning voltage V to tune the FM radio receiver such that the magnitude of the tuning voltage V varies from A to B as the AM local oscillator is tuned from f1 to f2.
Claim 4
Dependent Claim
271 words
In combination: an FM radio receiver tunable over the FM frequency band in response to the magnitude of a tuning voltage V having a low-to-high magnitude ratio A/B; an AM receiver including an AM local oscillator having a frequency f which varies from a low frequency f1 to a high frequency f 2 as the AM radio receiver is tuned across the AM band thereby to provide a low-to-high frequency ratio f1/f2 different from the ratio A/B; a pulse generator connected to the AM local oscillator for generating constant amplitude and constant width tuning pulses having the frequency f; a first converter connected to the pulse generator for generating a positive signal O1 at a first output terminal, the signal being defined by the expression O1 (K/2) f 1 where K is a constant; a second converter connected to the pulse generator for generating a negative signal O2 at a second output terminal, the signal being defined by the expression O2 -((K/2) f - Z) 2 where Z is a constant, the potential between the first and second output terminals being the tuning voltage V defined by the expression V O1 - O2 3 so that V Kf - Z, 4 where the magnitudes of K and Z are determined by the equations A Kf1 - Z 5 and B Kf2 - Z; 6 and means connected to the first and second output terminals for applying the tuning voltage V to tune the FM radio receiver such that the magnitude of the tuning voltage V varies from A to B as the AM local oscillator is tuned from f1 to f2.
References Cited (Backward Citations)
US3657654A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |