US3714620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sonic aircraft vehicle discriminator
Assignee: United States Department of the Navy
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Filing: 1970-12-18
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Granted: 1973-01-30
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Expires: 1990-12-18
Abstract
Abstract A sonic aircraft/vehicle discriminator adapted to receive sonic signals from both aircraft and land motor vehicles provides an output signal on receiving aircraft signals and a null on receiving the vehicle signals. The system by detecting slower fluctuations and less variations in the amplitudes of the vehicle signals than the aircraft signals subsequently attenuates the vehicle signals. The discriminator is comprised of serially connected filters, amplifiers, envelope detector, differentiator, integrator and Schmitt trigger.
Inventors
- 👤 S Biren
- 👤 T Costello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:52
CPC Classifications
G; G08; G08G; G08G5/00; G08G5/50; G08G5/51; G08G1/00; G08G1/01; G08G1/015; G08G5/20; G08G5/22; Y; Y10; Y10S; Y10S367/00; Y10S367/901
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
298 words
An aircraft/vehicle discriminator comprising: filter means adapted to receive an electrical signal indicative of an acoustic sound for passing only those signals within a predetermined frequency range; detector means operatively connected to the output of said filter means for detecting the envelope of said filter means output signal and for rectifying the detected signal including a first diode connected to receive the output of said filter means and providing a shunt to ground for signals of a predetermined polarity, a second diode connected to the output of said filter means for providing a path for filter means output signals of the other polarity, and a resistive-capacitive network adapted to receive the output of said second diode for smoothing out the signal from said second diode and providing an output that is an envelope of the output of said second diode; differentiator means operatively connected to the output of said detector means for providing an output whose amplituDe is a function of the slope of the output of said detector means including a capacitor operatively connected to the output of said detector means, and a grounded resistor connected to the output of said capacitor; integrator means adapted to receive the output of said differentiator means for providing an output upon reaching a predetermined amplitude that is a function of the integral of the output of said differentiator means including a pair of cascaded field effect transistors, a resistive-capacitive parallel network connected to the drain of one of said cascaded field effect transistors, and a zener diode connected to the output of said pair of cascaded field effect transistors; and a Schmitt trigger operatively connected to the output of said integrator means for providing an output indicative of whether the output of said integrator means has exceeded said predetermined amplitude.
Claim 2
Dependent Claim
298 words
An aircraft/vehicle discriminator comprising: filter means adapted to receive an electrical signal indicative of an acoustic sound for passing only those signals within a predetermined frequency range; detector means operatively connected to the output of said filter means for detecting the envelope of said filter means output signal and for rectifying the detected signal including a first diode connected to receive the output of said filter means and providing a shunt to ground for signals of a predetermined polarity, a second diode connected to the output of said filter means for providing a path for filter means output signals of the other polarity, and a resistive-capacitive network adapted to receive the output of said second diode for smoothing out the signal from said second diode and providing an output that is an envelope of the output of said second diode; differentiator means operatively connected to the output of said detector means for providing an output whose amplituDe is a function of the slope of the output of said detector means including a capacitor operatively connected to the output of said detector means, and a grounded resistor connected to the output of said capacitor; integrator means adapted to receive the output of said differentiator means for providing an output upon reaching a predetermined amplitude that is a function of the integral of the output of said differentiator means including a pair of cascaded field effect transistors, a resistive-capacitive parallel network connected to the drain of one of said cascaded field effect transistors, and a zener diode connected to the output of said pair of cascaded field effect transistors; and a Schmitt trigger operatively connected to the output of said integrator means for providing an output indicative of whether the output of said integrator means has exceeded said predetermined amplitude.
Claim 3
Dependent Claim
298 words
An aircraft/vehicle discriminator comprising: filter means adapted to receive an electrical signal indicative of an acoustic sound for passing only those signals within a predetermined frequency range; detector means operatively connected to the output of said filter means for detecting the envelope of said filter means output signal and for rectifying the detected signal including a first diode connected to receive the output of said filter means and providing a shunt to ground for signals of a predetermined polarity, a second diode connected to the output of said filter means for providing a path for filter means output signals of the other polarity, and a resistivecapacitive network adapted to receive the output of said second diode for smoothing out the signal from said second diode and providing an output that is an envelope of the output of said second diode; differentiator means operatively connected to the output of said detector means for providing an output whose amplituDe is a function of the slope of the output of said detector means including a capacitor operatively connected to the output of said detector means, and a grounded resistor connected to the output of said capacitor; integrator means adapted to receive the output of said differentiator means for providing an output upon reaching a predetermined amplitude that is a function of the integral of the output of said differentiator means including a pair of cascaded field effect transistors, a resistive-capacitive parallel network connected to the drain of one of said cascaded field effect transistors, and a zener diode connected to the output of said pair of cascaded field effect transistors; and a Schmitt trigger operatively connected to the output of said integrator means for providing an output indicative of whether the output of said integrator means has exceeded said predetermined amplitude.
Claim 4
Dependent Claim
298 words
An aircraft/vehicle discriminator comprising: filter means adapted to receive an electrical signal indicative of an acoustic sound for passing only those signals within a predetermined frequency range; detector means operatively connected to the output of said filter means for detecting the envelope of said filter means output signal and for rectifying the detected signal including a first diode connected to receive the output of said filter means and providing a shunt to ground for signals of a predetermined polarity, a second diode connected to the output of said filter means for providing a path for filter means output signals of the other polarity, and a resistivecapacitive network adapted to receive the output of said second diode for smoothing out the signal from said second diode and providing an output that is an envelope of the output of said second diode; differentiator means operatively connected to the output of said detector means for providing an output whose amplituDe is a function of the slope of the output of said detector means including a capacitor operatively connected to the output of said detector means, and a grounded resistor connected to the output of said capacitor; integrator means adapted to receive the output of said differentiator means for providing an output upon reaching a predetermined amplitude that is a function of the integral of the output of said differentiator means including a pair of cascaded field effect transistors, a resistive-capacitive parallel network connected to the drain of one of said cascaded field effect transistors, and a zener diode connected to the output of said pair of cascaded field effect transistors; and a Schmitt trigger operatively connected to the output of said integrator means for providing an output indicative of whether the output of said integrator means has exceeded said predetermined amplitude.
Claim 5
Dependent Claim
34 words
An aircraft/vehicle discriminator according to claim 1 further comprising: a first amplifier interposed between said filter means and said detector means; and a second amplifier interposed between said detector means and said differentiator means.
Claim 6
Dependent Claim
43 words
An aircraft/vehicle discriminator according to claim 2 wherein said first and second amplifiers further comprise: a first and second NPN transistor connected in cascade; and a resistive network connected between the base of said first transistor and the emitter of said second transistor
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |