US3836727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal receiver for receiving signals of different frequency
Assignee: US Philips Corp
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Filing: 1973-06-29
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Granted: 1974-09-17
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Expires: 1993-06-29
Abstract
Abstract A signal receiver for receiving signals of different frequencies comprising a group of frequency channels; each of which comprises a filter device tuned to a signal frequency and a detector connected to the filter. A device responsive to increases in the signal amplitudes is coupled to the filter devices of the group of frequency channels. A signal testing device is connected to the output of and is continuously activated by the device responding to increases in the signal amplitude to determine the validity of the received signals. The device for responding to increases in the signal amplitude comprises a smoothing filter connected to the detector, a first threshold circuit for obtaining a threshold value determined by the amplitude of the signals supplied to the detector, and a second threshold device for limiting the varying threshold value to a given value.
Inventors
- 👤 C Hillekens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:22
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45; H04Q1/453
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
A signal receiver comprising: a plurality of frequency channels; each channel including filter means tuned to a respective different signal frequency, detecting means connected to said filter means; discriminating means including a parallel connection of a capacitor and a resistor coupled to the input of said detecting means and having a time constant sufficient for producing a bias voltage corresponding substantially to amplitude increments during the initial build-up period of a signal in said filter means, thereby causing said detecting means to respond only to signals of increasing amplitude, and a threshold circuit coupled to the output of said detecting means for passing signals having amplitude increments greater than a predetermined threshold value; and signal testing means coupled to said discriminating means for responding to those signals only which exceed said threshold value during a predetermined testing period.
Claim 2
Dependent Claim
138 words
A signal receiver comprising: a plurality of frequency channels; each channel including filter means tuned to a respective different signal frequency, detecting means connected to said filter means; discriminating means including a parallel connection of a capacitor and a resistor coupled to the input of said detecting means and having a time constant sufficient for producing a bias voltage corresponding substantially to amplitude increments during the initial build-up period of a signal in said filter means, thereby causing said detecting means to respond only to signals of increasing amplitude, and a threshold circuit coupled to the output of said detecting means for passing signals having amplitude increments greater than a predetermined threshold value; and signal testing means coupled to said discriminating means for responding to those signals only which exceed said threshold value during a predetermined testing period.
Claim 3
Dependent Claim
29 words
A signal receiver according to claim 1, further comprising an additional threshold circuit coupled to said parallel connection to limit said bias voltage to a predetermined second threshold value.
Claim 4
Dependent Claim
42 words
A signal receiver according to claim 2, wherein said detecting means includes a first transistor having a base connected to said filter means, an emitter grounded through said parallel connection, and a collector connected to said threshold circuit through a detecting diode.
Claim 5
Dependent Claim
43 words
A signal receiver according to claim 3, wherein said threshold circuit includes a second transistor having a base connected to said detecting diode, an emitter grounded through a reference voltage source determining threshold value and a collector connected to said signal testing means.
References Cited (Backward Citations)
US3470532A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |