US4403185A
Expired / Lapsed
US
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Process and device for detecting frequency variations
Assignee: Baxter International Inc
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Filing: 1982-06-09
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Granted: 1983-09-06
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Expires: 2002-06-09
Abstract
Abstract A process and device are provided for detecting frequency variations of waveforms (10). The waveform (10) is sensed and a first signal (16) is provided with each occurrence of the sensed waveform (10). Each time that the first signal is provided, a measuring pulse (24) that is different in duration than the sensed waveform (10) is provided. The sensed waveform (10) and the measuring pulse (24) are simultaneously transmitted to a gate (28) which provides a signal at its output to indicate if the frequency of the sensed waveform has varied more than a predetermined amount.
Inventors
- 👤 Donald E. Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:13
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/15
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
A device for detecting frequency variations which comprises: means for sensing a rectangular waveform, the frequency variation of which is to be detected; a differentiator circuit for providing a spike corresponding to each occurrence of the negative transition of the sensed rectangular waveform; a monostable multivibrator for initiating a rectangular measuring pulse upon each occurrence of said spike, said measuring pulse being different in duration than the low portion of the sensed waveform; an AND gate; means for transmitting the sensed waveform to one input of the AND gate and for transmitting the measuring pulse to another input of the AND gate; said AND gate being operable for providing a train of pulses at its output indicating that the frequency of the sensed rectangular wave has varied by more than a predetermined amount.
Claim 2
Independent Claim
133 words
A device for detecting frequency variations which comprises: means for sensing a rectangular waveform, the frequency variation of which is to be detected; a differentiator circuit for providing a spike corresponding to each occurrence of the negative transition of the sensed rectangular waveform; a monostable multivibrator for initiating a rectangular measuring pulse upon each occurrence of said spike, said measuring pulse being different in duration than the low portion of the sensed waveform; an AND gate; means for transmitting the sensed waveform to one input of the AND gate and for transmitting the measuring pulse to another input of the AND gate; said AND gate being operable for providing a train of pulses at its output indicating that the frequency of the sensed rectangular wave has varied by more than a predetermined amount.
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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |