US3851301A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for balancing an ultrasonic detection system
Assignee: Kidde Inc
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Filing: 1972-09-15
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Granted: 1974-11-26
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Expires: 1992-09-15
Abstract
Abstract A method and apparatus for equalizing the sensitivity of an ultrasonic detection system of the type using Doppler frequency in which a test unit generates a spectrum of energy of different frequencies, and transmits the spectrum through transducers located in the areas to be protected, to create, at a receiving transducer, an average standing-wave power density proportional to the total traveling-wave power density. The average standingwave power density is measured to provide a means of equalizing detection sensitivity.
Inventors
- 👤 R Fester
- 👤 E Demers
- 👤 G Hectus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:13
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/52; G01S7/52004
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
214 words
Apparatus for adjusting the sensitivity of a receiver transducer of an intruder detection system for protecting a given space, said system being of the type including means for producing a base frequency signal fc which is transmitted into said space and from which a range of doppler frequency signals are generated in the space as a function of physical events occurring in the space, alarm means, and first means responsive to the base frequency signal fc and a range of doppler frequency signals received from said space to actuate said alarm means; the improvement comprising at least one receiver transducer means in said space whose sensitivity is to be adjusted, means for transmitting into said space for receipt by said receiver transducer a test signal independent of said base frequency signal, said test signal having a spectrum of components of energy of different frequencies including those which would normally include at least a portion of the doppler frequencies generated in said space as a function of said base frequency signal, means coupled to said receiver transducer means for producing an output signal in response to and representative of the amplitudes of spectral components of the test signal received by said receiver transducer means, and means for adjusting the sensitivity of said receiver transducer means.
Claim 2
Dependent Claim
214 words
Apparatus for adjusting the sensitivity of a receiver transducer of an intruder detection system for protecting a given space, said system being of the type including means for producing a base frequency signal fc which is transmitted into said space and from which a range of doppler frequency signals are generated in the space as a function of physical events occurring in the space, alarm means, and first means responsive to the base frequency signal fc and a range of doppler frequency signals received from said space to actuate said alarm means; the improvement comprising at least one receiver transducer means in said space whose sensitivity is to be adjusted, means for transmitting into said space for receipt by said receiver transducer a test signal independent of said base frequency signal, said test signal having a spectrum of components of energy of different frequencies including those which would normally include at least a portion of the doppler frequencies generated in said space as a function of said base frequency signal, means coupled to said receiver transducer means for producing an output signal in response to and representative of the amplitudes of spectral components of the test signal received by said receiver transducer means, and means for adjusting the sensitivity of said receiver transducer means.
Claim 3
Dependent Claim
50 words
Apparatus as in claim 1 wherein said transmitting means transmits into the space to be protected a test signal having a spectrum of components of energy in the range fc + or - fd, where fd is the range of doppler frequency signals to which said first means is responsive.
Claim 4
Dependent Claim
25 words
Apparatus as in claim 1 wherein said transmitting means transmits a test signal whose components of energy are of substantially equal amplitude over the spectrum.
Claim 5
Dependent Claim
28 words
Apparatus as in claim 2 wherein said transmitting means includes oscillating means, and means for changing the frequency of the components of energy produced by said oscillating means.
Claim 6
Dependent Claim
26 words
Apparatus as in claim 4 wherein said means for changing the frequency of the components of energy produced by said oscillating means comprises a noise source.
Claim 7
Dependent Claim
23 words
Apparatus as in claim 1 wherein said transmitting means also includes means for transmitting only the base frequency signal fc for the system.
Claim 8
Dependent Claim
18 words
Apparatus as in claim 1 wherein there are a plurality of said receiver transducers in the said space.
Claim 9
Dependent Claim
27 words
Apparatus as in claim 1 wherein said means for adjusting the amplitude of said output signal is located at the receiver transducer whose sensitivity is being adjusted.
Claim 10
Dependent Claim
28 words
Apparatus as in claim 1 wherein said means for producing said output signal includes test receiver means in said space separate from said first means of the system.
Claim 11
Dependent Claim
31 words
Apparatus as in claim 9 wherein said test receiver means is adapted to have electrically coupled thereto said receiver transducer located in the given space whose sensitivity is to be adjusted.
Claim 12
Dependent Claim
24 words
Apparatus as in claim 10 wherein said means for adjusting the amplitude of said output signal comprises attenuator means located at the receiver transducer.
Claim 13
Dependent Claim
33 words
Apparatus as in claim 10 wherein said test receiver means includes means for producing an indication of the amplitude of the energy received by said receiver transducer means whose sensitivity is being adjusted.
Claim 14
Dependent Claim
24 words
Apparatus as in claim 12 wherein said means for adjusting the amplitude of said output signal comprises attenuator means located at the receiver transducer.
Claim 15
Dependent Claim
12 words
Apparatus as in claim 12 wherein said indicating means includes a meter.
Claim 16
Dependent Claim
56 words
Apparatus as in claim 9 wherein a said receiver transducer includes a fixture mounted at a predetermined location in said space to which a said receiver transducer is detachably connected, and said test receiver means includes means adapted to be connected to said fixtUre with the said receiver transducer means being connected to said test receiver.
Claim 17
Dependent Claim
27 words
Apparatus as in claim 10 wherein said test receiver means produces said output signal which is proportional to the average energy received by said receiver transducer means.
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) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |