US4389638A
Expired / Lapsed
US
⏱️ 0.0 years remaining
I.C. Alarm signal generator
Assignee: Allegro Microsystems LLC
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Filing: 1981-09-30
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Granted: 1983-06-21
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Expires: 2001-09-30
Abstract
Abstract A yelping alarm signal generator has a current controlled audio oscillator with a feedback loop around it that produces a control current that is a direct function of the oscillation frequency so that only one capacitor external to the integrated circuits is required.
Inventors
- 👤 Walter S. Gontowski, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:28
CPC Classifications
G; G08; G08B; G08B3/00; G08B3/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
A yelping alarm signal generator comprising: a current controlled oscillator means for periodically charging and discharging a capacitor at a rate that is a function of a control current; and a frequency-to-current converter means being connected from an output to an input of said oscillator means for producing said control current and for setting the amplitude of said control current at a value that is a function of said rate of periodic charging and discharging.
Claim 2
Dependent Claim
75 words
A yelping alarm signal generator comprising: a current controlled oscillator means for periodically charging and discharging a capacitor at a rate that is a function of a control current; and a frequency-to-current converter means being connected from an output to an input of said oscillator means for producing said control current and for setting the amplitude of said control current at a value that is a function of said rate of periodic charging and discharging.
Claim 3
Dependent Claim
57 words
The alarm signal generator of claim 1 wherein said frequency-to-current converter means is comprised of a binary counter means for producing a multi-line parallel binary coded signal corresponding to the output frequency of said current controlled oscillator means; and a digital-to-current converter for determining the amplitude of said control current in correspondence with said binary coded signal.
Claim 4
Dependent Claim
86 words
The alarm signal generator of claim 1 wherein said frequency-to-current converter means is comprised of a counter means for producing a periodic signal having a output frequency that is a fixed fraction of the frequency of said current controlled oscillator means of said oscillator means; a binary counter means for producing a multi-line binary coded signal corresponding to said fixed fraction frequency from said counter means; and a digital-to-current converter means for determining the amplitude of said control current in correspondence with said binary coded signal.
Claim 5
Dependent Claim
30 words
The alarm signal generator of claim 3 wherein said binary counter means is adapted to reset at a predetermined count to impart to said control current a periodic ramp waveform.
Claim 6
Dependent Claim
34 words
The alarm signal generator of claim 3 additionally comprising an output driver means being connected to the output of said oscillator means for driving an electro-acoustic transducer at said frequency of said oscillator 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) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |