US3676699A
Expired / Lapsed
US
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Asynchronous pulse width filter
Assignee: United States Department of the Navy
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Filing: 1971-09-13
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Granted: 1972-07-11
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Expires: 1991-09-13
Abstract
Abstract An asynchronous pulse width filter having four two-state logic circuits, the first having a retriggerable circuit capable of delaying the leading edge of an input pulse by a presettable time Delta t, coupled to a second logic circuit capable of detecting the trailing edge of the input pulse after the delayed leading edge, coupled to a third logic circuit of non-retriggerable capabilities but capable of delaying the trailing edge from the prior logic circuit a fixed amount of time Delta t and coupled to a fourth logic circuit capable of triggering a leading edge at the trailing edge of the output pulse of the second logic circuit and of triggering a trailing edge at the trailing edge of the delayed output Delta t of the third logic circuit to provide discrimination of pulse width to reproduce valid pulses precisely in pulse width and in relative position.
Inventors
- 👤 Samuel C Warren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:22
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/125; H03K5/1252; G; G01; G01R; G01R29/00; G01R29/02; G01R29/027; G01R29/0273
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
297 words
An asynchronous pulse width filter circuit comprising: an input of random width pulses; a first retriggerable multivibrator having an input coupled to said input of random pulses, having a delay network capable of delaying the leading edges of input pulses by a predetermined amount, and having an output for passing selected pulses of width equal to and greater than the predetermined amount; a first flip-flop circuit having inputs coupled to said input of random width pulses and to said output of said first multivibrator to trigger a pulse at the delayed leading edge of the selected pulses from said first multivibrator terminating in a trailing edge at the trailing edge of the selected pulse from said input of random width pulses on an output thereof; a second non-retriggerable multivibrator having an input coupled to the input of said random pulses and having a delay network capable of delaying the trailing edge on the output of said first flip-flop circuit on an output thereof said predetermined amount; and a second flip-flop circuit having one input coupled to the output of said second multivibrator and one input coupled to the output of said first flip-flop circuit to produce a pulse on an output thereof with a leading edge coinciding in time with the first delayed leading edge of the selected pulse output of said first multivibrator and with a trailing edge coinciding in time with the trailing edge of the selecting pulse with said second delay on the output of said second multivibrator whereby valid pulses of greater width than the width produced by said predetermined time delay will be passed through said two multivibrators and two flip-flops with the same pulse width and in the same time relations as corresponding selected pulses on said input of random pulses.
Claim 2
Dependent Claim
297 words
An asynchronous pulse width filter circuit comprising: an input of random width pulses; a first retriggerable multivibrator having an input coupled to said input of random pulses, having a delay network capable of delaying the leading edges of input pulses by a predetermined amount, and having an output for passing selected pulses of width equal to and greater than the predetermined amount; a first flip-flop circuit having inputs coupled to said input of random width pulses and to said output of said first multivibrator to trigger a pulse at the delayed leading edge of the selected pulses from said first multivibrator terminating in a trailing edge at the trailing edge of the selected pulse from said input of random width pulses on an output thereof; a second non-retriggerable multivibrator having an input coupled to the input of said random pulses and having a delay network capable of delaying the trailing edge on the output of said first flip-flop circuit on an output thereof said predetermined amount; and a second flip-flop circuit having one input coupled to the output of said second multivibrator and one input coupled to the output of said first flip-flop circuit to produce a pulse on an output thereof with a leading edge coinciding in time with the first delayed leading edge of the selected pulse output of said first multivibrator and with a trailing edge coinciding in time with the trailing edge of the selecting pulse with said second delay on the output of said second multivibrator whereby valid pulses of greater width than the width produced by said predetermined time delay will be passed through said two multivibrators and two flip-flops with the same pulse width and in the same time relations as corresponding selected pulses on said input of random pulses.
Claim 3
Dependent Claim
39 words
An asynchronous pulse width filter circuit as set forth in claim 1 wherein said delay networks of said first retriggerable and said second non-retriggerable multivibrators are resistance-capacitance networks of values to establish the same said predetermined delay in time.
Claim 4
Dependent Claim
96 words
An asynchronous pulse width filter circuit as set forth in claim 2 wherein said inputs to said first retriggerable and second non-retriggerable multivibrators each include an inverted input OR gate and an AND gate in which the input of random width pulses is applied to the AND gate of said first retriggerable multivibrator and to the inverted input OR gate of said second non-retriggerable multivibrator, the inverted inputs of the OR gate of said first multivibrator being grounded and the remaining inputs to the AND gate of said second multivibrator being fixed to a ''''1'''' state.
Claim 5
Dependent Claim
59 words
An asynchronous pulse width filter circuit as set forth in claim 3 wherein said inverted input OR gate in the input of said second multivibrator has one input fed back from the second multivibrator output to prevent said second multivibrator from retriggering at the trailing edges of each random width pulse whereby triggering is accomplished for said selected pulses.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |