US3585512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency discriminator to eliminate the effect of noise pulse width modulations
Assignee: International Standard Electric Corp
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Filing: 1969-05-13
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Granted: 1971-06-15
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Expires: 1989-05-13
Abstract
Abstract To eliminate the effects of noise width modulations, the input FM pulse signals are applied to a PNP transistor the duration of whose output pulses is each extended for a period equal to the ''''turnoff'''' time. These extended pulses are combined in an AND gate with the input pulse signals leaving pulses of a constant width equal to the ''''turnoff'''' time. The latter pulses are applied to an NPN transistor whose ''''turnoff'''' time (storage time + fall time) after each pulse is such that the leading edge of the next pulse coincides with some point on the current fall time (voltage rise time) in the NPN-transistor which point varies with the pulse frequency. Frequency centering of the discriminator is accomplished by feeding back the integrated output voltage to the base of the second-mentioned transistor to control its ''''turnoff'''' time.
Inventors
- 👤 Gerhard Gunter Gassmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:08
CPC Classifications
H; H03; H03K; H03K9/00; H03K9/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
167 words
A frequency discriminator comprising: a source of input pulse signals; a first transistor coupled to said source having a given delay in changing between its saturated and nonconductive states in response to input pulses, to thereby produce delayed pulse signals; an AND gate coupled to said source and to the output of said first transistor for producing output pulse signals each having a constant width equal to said given delay; and means responsive to the frequency of said constant width output pulse signals for producing an output that changes in amplitude with variations in said frequency, said means includes a second transistor also having a given delay in changes between its saturated and nonconductive states, the given delay of said second transistor being such that the application of a leading edge of each pulse to the second transistor occurs during the fall-time of the collector current of said first transistor and at a point during said current fall which varies with the frequency of said pulse signals.
Claim 2
Dependent Claim
167 words
A frequency discriminator comprising: a source of input pulse signals; a first transistor coupled to said source having a given delay in changing between its saturated and nonconductive states in response to input pulses, to thereby produce delayed pulse signals; an AND gate coupled to said source and to the output of said first transistor for producing output pulse signals each having a constant width equal to said given delay; and means responsive to the frequency of said constant width output pulse signals for producing an output that changes in amplitude with variations in said frequency, said means includes a second transistor also having a given delay in changes between its saturated and nonconductive states, the given delay of said second transistor being such that the application of a leading edge of each pulse to the second transistor occurs during the fall-time of the collector current of said first transistor and at a point during said current fall which varies with the frequency of said pulse signals.
Claim 3
Dependent Claim
15 words
A frequency discriminator according to claim 1, wherein said transistors are of opposite conductivity type.
Claim 4
Dependent Claim
57 words
A frequency discriminator according to claim 1, further including means coupled to the output of said second transistor for producing an output voltage; and means for feeding back at least a portion of said output voltage to said second transistor to vary said given delay thereof and to thereby control the center frequency of its discriminating curve.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |