US3877004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alarm apparatus
Assignee: Denso Corp
•
Filing: 1973-10-05
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Granted: 1975-04-08
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Expires: 1993-10-05
Abstract
Abstract An alarm apparatus comprises detector means for detecting the number of rotation of a rotating body as an electrical intermittent frequency, a digital-analog converter for converting the intermittent frequency from the detector means into a DC voltage, a voltage comparator for discriminating the amplitude of an output voltage from the digital-analog converter, an alarm unit controlled by an output from the voltage comparator and feedback means for feeding back the output from the voltage comparator to the input side of the digital-analog converter. The voltage comparator serves as a low-frequency oscillator in cooperation with the feedback means thereby to sound an intermittent alarm.
Inventors
- 👤 Masashi Okada
- 👤 Yoshihiko Kondo
- 👤 Tadao Nojiri
- 👤 Yukio Muramatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:09
CPC Classifications
G; G01; G01P; G01P1/00; G01P1/07; G01P1/08; G01P1/10; G01P1/103
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
123 words
An alarm apparatus comprising detector means for detecting a detectable quantity such as the number of rotation of a rotating body as an electric intermittent frequency, a digital-analog converter for converting the intermittent frequency from said detector means into a DC voltage, at least one voltage comparator for discriminating the amplitude of an output voltage from said digital-analog converter and producing a warning signal when the output voltage exceeds a given level, an alarm unit connected to and controlled by said warning signal from said voltage comparator and feedback means for feeding back the output from said voltage comparator to the input side of said digital-analog converter, whereby said voltage comparator serves as a lowfrequency oscillator circuit in cooperation with said feedback means.
Claim 2
Dependent Claim
123 words
An alarm apparatus comprising detector means for detecting a detectable quantity such as the number of rotation of a rotating body as an electric intermittent frequency, a digital-analog converter for converting the intermittent frequency from said detector means into a DC voltage, at least one voltage comparator for discriminating the amplitude of an output voltage from said digital-analog converter and producing a warning signal when the output voltage exceeds a given level, an alarm unit connected to and controlled by said warning signal from said voltage comparator and feedback means for feeding back the output from said voltage comparator to the input side of said digital-analog converter, whereby said voltage comparator serves as a lowfrequency oscillator circuit in cooperation with said feedback means.
Claim 3
Dependent Claim
145 words
An alarm apparatus comprising detector means for detecting a detectable quantity such as the number of rotation of a rotating body as an electric intermittent frequency, a digital-analog converter for converting the intermittent frequency from said detector means into a DC voltage, an emitter follower transistor, the base circuit of which is connected to the output side of said digital-analog converter, a plurality of voltage comparators, each thereof connected to the emitter circuit of said emitter follower transistor, for discriminating the amplitude of an output voltage from said digital-analog converter, feedback means for feeding back an output voltage from one of the plurality of voltage comparators having the highest operating voltage to the input side of said digital-analog converter, whereby said voltage comparator having the highest operating voltage serves as a low-frequency oscillator circuit in cooperation with said feedback means and controls an alarm unit.
Claim 4
Dependent Claim
145 words
An alarm apparatus comprising detector means for detecting a detectable quantity such as the number of rotation of a rotating body as an electric intermittent frequency, a digital-analog converter for converting the intermittent frequency from said detector means into a DC voltage, an emitter follower transistor, the base circuit of which is connected to the output side of said digital-analog converter, a plurality of voltage comparators, each thereof connected to the emitter circuit of said emitter follower transistor, for discriminating the amplitude of an output voltage from said digital-analog converter, feedback means for feeding back an output voltage from one of the plurality of voltage comparators having the highest operating voltage to the input side of said digital-analog converter, whereby said voltage comparator having the highest operating voltage serves as a low-frequency oscillator circuit in cooperation with said feedback means and controls an alarm unit.
Claim 5
Dependent Claim
80 words
An alarm apparatus according to claim 1, wherein said feedback means comprises a resistor connected between the output of said voltage comparator and the input of said digital-analog converter, and said digital-analog converter comprises a differentiating capacitor with one end connected to the input of said digital-analog converter and the other end to ground through a first diode and an integrating capacitor with one end connected to said differentiating capacitor through a second diode and the other end to ground.
Claim 6
Dependent Claim
24 words
An alarm apparatus according to claim 3 which further comprises a resistor connected between a power source and the input of said digital-analog converter.
Claim 7
Dependent Claim
82 words
An alarm apparatus according to claim 1, wherein said feedback means comprises a resistor connected between the output of said voltage comparator and the input of said digital-analog converter, and said digital-analog converter comprises a differentiating capacitor with one end connected to the input of said digital-analog converter and the other to a power source through a first diode and an integrating capacitor with one end connected to said differentiating capacitor through a second diode and the other to the power source.
Claim 8
Dependent Claim
65 words
An alarm apparatus according to claim 1, wherein said feedback means comprises a resistor connected between the output of said voltage capacitor and the input of said digital-analog converter, and said digital-analog converter comprises a p-n-p transistor whose base is connected to a power source, emitter to the input of said digital-analog converter through a differentiating capacitor and collector to ground through an integrating capacitor.
Claim 9
Dependent Claim
65 words
An alarm apparatus according to claim 1, wherein said feedback means comprises a resistor connected between the output of said voltage comparator and the input of said digital-analog converter, and said digital-analog converter comprises an n-p-n transistor whose base is connected to the input of said digital-analog converter through a differentiating capacitor, emitter to ground and collector to a power source through an integrating capacitor.
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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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |