Patent US3317841A successfully refreshed from Google Patents.
US3317841A
Expired / Lapsed
US
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Radio receiver with alarm means operative when input signal is below predetermined level
Assignee: R A MACPLUM IND Inc
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Filing: 1964-03-17
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Granted: 1967-05-02
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Expires: 1984-03-17
Abstract
No abstract record available.
Inventors
- 👤 Umanoff Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:14
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/22; H04B1/24; B; B62; B62B; B62B3/00; B62B3/14; B62B3/1408; H05; H05K; H05K11/00; B62B2501/00; B62B2501/06; B62B2501/065
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
161 words
AN ALARM CIRCUIT FOR A RADIO RECEIVER WHICH OPERATES TO PRODUCE AN OSCILLATION WHEN THE RADIO INPUT FALLS BELOW A PREDETERMINED LEVEL COMPRISING: A RADIO FREQUENCY AMPLIFIER-DETECTOR CIRCUIT WHICH GENERATES A DIRECT CURRENT SIGNAL PROPORTIONAL TO THE RADIO INPUT; AN AUIDOFREQUENCY AMPLIFIER HAVING ITS INPUT COUPLED TO SAID DETECTOR AND ALSO HAVING A POSITIVE FEED-BACK CIRCUIT INCLUDING A TRANSISTOR HAVING A COLLECTOR AND ALSO A BASE CONNECTED BOTH TO THE OUTPUT SIDE OF SAID DETECTOR AND TO GROUND AND HAVING ALSO AN EMITTER CONNECTED ONLY TO GROUND, SAID FEED-BACK CIRCUIT BEING COUPLED BETWEEN THE OUTPUT AND INPUT CIRCUITS TO PRODUCE OSCILLATION; AND A CONTROL CIRCUIT INCLUDING A BIASED DIODE CONNECTED ACROSS A PORTION OF SAID FEED-BACK CIRCUIT FOR SHORT-CIRCUITING THE FEED-BACK CURRENT WHEN THE DIODE IS MADE CONDUCTING, SAID DIODE HAVING ITS CATHODE CONNECTED TO SAID COLLECTOR OF SAID TRANSISTOR THUS TO BE COUPLED THROUGH COLLECTOR TO BASE OF SAID TRANSISTOR TO THE DETECTOR CIRCUIT FOR CONTROL OF ITS BIAS VOLTAGE.
Claim 2
Dependent Claim
161 words
AN ALARM CIRCUIT FOR A RADIO RECEIVER WHICH OPERATES TO PRODUCE AN OSCILLATION WHEN THE RADIO INPUT FALLS BELOW A PREDETERMINED LEVEL COMPRISING: A RADIO FREQUENCY AMPLIFIER-DETECTOR CIRCUIT WHICH GENERATES A DIRECT CURRENT SIGNAL PROPORTIONAL TO THE RADIO INPUT; AN AUIDOFREQUENCY AMPLIFIER HAVING ITS INPUT COUPLED TO SAID DETECTOR AND ALSO HAVING A POSITIVE FEED-BACK CIRCUIT INCLUDING A TRANSISTOR HAVING A COLLECTOR AND ALSO A BASE CONNECTED BOTH TO THE OUTPUT SIDE OF SAID DETECTOR AND TO GROUND AND HAVING ALSO AN EMITTER CONNECTED ONLY TO GROUND, SAID FEED-BACK CIRCUIT BEING COUPLED BETWEEN THE OUTPUT AND INPUT CIRCUITS TO PRODUCE OSCILLATION; AND A CONTROL CIRCUIT INCLUDING A BIASED DIODE CONNECTED ACROSS A PORTION OF SAID FEED-BACK CIRCUIT FOR SHORT-CIRCUITING THE FEED-BACK CURRENT WHEN THE DIODE IS MADE CONDUCTING, SAID DIODE HAVING ITS CATHODE CONNECTED TO SAID COLLECTOR OF SAID TRANSISTOR THUS TO BE COUPLED THROUGH COLLECTOR TO BASE OF SAID TRANSISTOR TO THE DETECTOR CIRCUIT FOR CONTROL OF ITS BIAS VOLTAGE.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-05-01 | 1970-10-31 | 1971-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-05-01 | 1974-10-31 | 1975-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-05-01 | 1978-10-31 | 1979-05-02 | $7700.00 | Window Closed / Lapsed |