US3796831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse modulation and detection communications system
Assignee: RCA Corp
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Filing: 1972-11-13
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Granted: 1974-03-12
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Expires: 1992-11-13
Abstract
Abstract In a pulse modulation and detection communications system suitable for use with high-power carrier sources such as light emitting diodes or transferred electron oscillators, the zero axis crossings of an audio frequency signal are used to control the output pulse width of the carrier source. The carrier pulses are detected and frequency divided to provide a square wave exhibiting the same zero axis crossings as the original audio frequency signal. The detected square wave is filtered before being applied to an audio signal output device.
Inventors
- 👤 J Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:04
CPC Classifications
H; H04; H04B; H04B10/00; H04B14/00; H04B14/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
340 words
A pulse modulation communications system comprising, in combination: a signal input means adapted to receive an input signal definable by zero axis crossings, first means coupled to said signal input means for amplifying and limiting said input signal to provide a substantially square wavE signal having a period determined by the zero axis crossings of said input signal; second means coupled to said first means for generating a pulse of a predetermined pulse width in response to each point of discontinuity of said square wave; third means including an output device coupled to said second means for generating and transmitting a carrier signal during each pulse generated by said second means; detection means responsive to said carrier signal for deriving a detected pulse signal having a pulse width determined by the transmitted carrier signal; frequency divider means coupled to said detection means, said frequency divider means being responsive to said detected pulse signal for providing a substantially square wave signal having a period determined by the time duration between successively detected pulses; and output means including filter means coupled to said frequency divider means for filtering the square wave signal provided by said frequency divider means to provide an output signal which is a substantial reproduction of said input signal wherein said second means comprises: an exclusive-OR logic gate having first and second input terminals and an output terminal, a one-shot multivibrator having an input terminal, an output terminal and a complementary output terminal, and a bistable multivibrator having a toggle input and an output terminal; wherein said first input terminal of said logic gate is coupled to said first means and said output terminal of said logic gate is coupled to said input terminal of said one-shot multivibrator; wherein said output terminal of said one-shot multivibrator is coupled to said third means and said complementary output of said one-shot multivibrator is coupled to said toggle input of said bistable multivibrator; and wherein said output terminal of said bistable multivibrator is coupled to said second input of said exclusive-OR gate.
Claim 2
Dependent Claim
340 words
A pulse modulation communications system comprising, in combination: a signal input means adapted to receive an input signal definable by zero axis crossings, first means coupled to said signal input means for amplifying and limiting said input signal to provide a substantially square wavE signal having a period determined by the zero axis crossings of said input signal; second means coupled to said first means for generating a pulse of a predetermined pulse width in response to each point of discontinuity of said square wave; third means including an output device coupled to said second means for generating and transmitting a carrier signal during each pulse generated by said second means; detection means responsive to said carrier signal for deriving a detected pulse signal having a pulse width determined by the transmitted carrier signal; frequency divider means coupled to said detection means, said frequency divider means being responsive to said detected pulse signal for providing a substantially square wave signal having a period determined by the time duration between successively detected pulses; and output means including filter means coupled to said frequency divider means for filtering the square wave signal provided by said frequency divider means to provide an output signal which is a substantial reproduction of said input signal wherein said second means comprises: an exclusive-OR logic gate having first and second input terminals and an output terminal, a one-shot multivibrator having an input terminal, an output terminal and a complementary output terminal, and a bistable multivibrator having a toggle input and an output terminal; wherein said first input terminal of said logic gate is coupled to said first means and said output terminal of said logic gate is coupled to said input terminal of said one-shot multivibrator; wherein said output terminal of said one-shot multivibrator is coupled to said third means and said complementary output of said one-shot multivibrator is coupled to said toggle input of said bistable multivibrator; and wherein said output terminal of said bistable multivibrator is coupled to said second input of said exclusive-OR gate.
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) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |