Patent US4121164A successfully refreshed from Google Patents.
US4121164A
Expired / Lapsed
US
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Automatic trigger circuit
Assignee: Tektronix Inc
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Filing: 1977-04-27
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Granted: 1978-10-17
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Expires: 1997-04-27
Abstract
Abstract An automatic trigger circuit for an oscilloscope includes a clock driven up-down counter and a digital-to-analog converter to automatically seek a suitable triggering level in the absence of an input triggering signal. When such level is established, the associated sweep generator is triggered, producing a display trace. Thereafter,the sweep generator is cyclically retriggered as the sweep "free runs."
Inventors
- 👤 Dennis LeRoy Feucht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:53
CPC Classifications
G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; G01R13/32
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
156 words
An automatic trigger circuit, comprising: a signal input; a variable reference voltage source for providing a variably adjustable voltage level within a predetermined triggering voltage window; a comparator having a first input terminal coupled to said signal input and a second input terminal coupled to said reference voltage source, said comparator generating triggering signals in response to a comparison between said signal input and said variably adjustable voltage level; scanning means for causing said reference voltage automatically to scan through said triggering voltage window, said scanning means including means for generating a triangular voltage waveform the peak-to-peak amplitude of which is at least twice the peak-to-peak amplitude of said triggering voltage window, said scanning means further including means for summing said triangular voltage waveform with said variably adjustable voltage level to provide a scanning reference voltage; and control means for disabling said scanning means for a predetermined period of time after a triggering signal is generated.
Claim 2
Dependent Claim
156 words
An automatic trigger circuit, comprising: a signal input; a variable reference voltage source for providing a variably adjustable voltage level within a predetermined triggering voltage window; a comparator having a first input terminal coupled to said signal input and a second input terminal coupled to said reference voltage source, said comparator generating triggering signals in response to a comparison between said signal input and said variably adjustable voltage level; scanning means for causing said reference voltage automatically to scan through said triggering voltage window, said scanning means including means for generating a triangular voltage waveform the peak-to-peak amplitude of which is at least twice the peak-to-peak amplitude of said triggering voltage window, said scanning means further including means for summing said triangular voltage waveform with said variably adjustable voltage level to provide a scanning reference voltage; and control means for disabling said scanning means for a predetermined period of time after a triggering signal is generated.
Claim 3
Dependent Claim
56 words
An automatic trigger circuit in accordance with claim 1 wherein said means for generating a triangular voltage waveform comprises a clock which produces clock pulses at a predetermined rate, an up-down counter which counts said clock pulses and produces a count output therefrom, and a digital-to-analog converter which converts said count output to an analog voltage.
Claim 4
Dependent Claim
44 words
An automatic trigger circuit in accordance with claim 1 wherein said control means includes a monostable multivibrator which is responsive to said triggering signal to stop said scanning reference voltage at the level in said triggering window at which said triggering signal is generated.
References Cited (Backward Citations)
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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) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |