US3890575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Window trip monitor and comparator circuit
Assignee: Bendix Corp
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Filing: 1969-07-17
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Granted: 1975-06-17
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Expires: 1989-07-17
Abstract
Abstract A window trip monitor circuit provides a warning indication when the absolute value of an input signal exceeds a trip level. An absolute value amplifier converts the input signal to a unipolar signal. A high gain level detector compares the unipolar signal with a reference signal and provides the warning indication when the unipolar signal exceeds the reference signal. The window trip monitor circuit may be used as a window trip comparator circuit by comparing two input signals and providing a difference signal to the absolute value amplifier.
Inventors
- 👤 David A Tawfik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:11
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; H; H03; H03K; H03K5/00; H03K5/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
89 words
A window trip circuit for monitoring a signal and providing a warning indication when the signal amplitude exceeds a trip level, comprising: an absolute value amplifier responsive to the signal for providing a unipolar output having an amplitude corresponding to the amplitude of the signal; means for providing a reference signal corresponding to the trip level; and a level detector for receiving the unipolar output and the reference signal and for providing the warning indication when the amplitude of the unipolar signal exceeds the amplitude of the reference signal.
Claim 2
Dependent Claim
89 words
A window trip circuit for monitoring a signal and providing a warning indication when the signal amplitude exceeds a trip level, comprising: an absolute value amplifier responsive to the signal for providing a unipolar output having an amplitude corresponding to the amplitude of the signal; means for providing a reference signal corresponding to the trip level; and a level detector for receiving the unipolar output and the reference signal and for providing the warning indication when the amplitude of the unipolar signal exceeds the amplitude of the reference signal.
Claim 3
Dependent Claim
25 words
A circuit as described in claim 1, in which the reference signal means includes means for varying the reference signal thereby varying the trip level.
Claim 4
Dependent Claim
19 words
A circuit as described in claim 1, in which the signal may be either an a.c. or d.c. signal.
Claim 5
Dependent Claim
53 words
A circuit as described in claim 1, in which the level detector provides an output at a first level when the amplitude of the unipolar signal is below the amplitude of the reference signal and at a second level when the amplitude of the unipolar signal exceeds the amplitude of the reference signal.
Claim 6
Dependent Claim
26 words
A circuit as described in claim 4, in which the level detector output reverses polarity when the unipolar signal exceeds the amplitude of the reference signal.
Claim 7
Dependent Claim
24 words
A circuit as described in claim 4, additionally comprising means for changing the reference signal in response to the output of the level detector.
Claim 8
Dependent Claim
43 words
A circuit as described in claim 4, additionally comprising means for providing hysteresis including feedback means for feeding back a portion of the level detector output to the reference signal so that the trip level changes in accordance with the level detector output.
Claim 9
Dependent Claim
19 words
A circuit as described in claim 7, in which the feedback means includes adjustable resistance means for changing hysteresis.
Claim 10
Dependent Claim
21 words
A circuit as described in claim 8, in which the hysteresis is adjusted by a single resistor in the feedback means.
Claim 11
Dependent Claim
18 words
A circuit as described in claim 2, in which the reference signal is adjusted by a single resistor.
Claim 12
Dependent Claim
16 words
A circuit as described in claim 1, in which the level detector comprises an operational amplifier.
Claim 13
Dependent Claim
80 words
A circuit as described in claim 1, in which the absolute value amplifier comprises: a resistance network for passing a portion of the signal; an operational rectifier Responsive only to a first sense of the signal for providing an output having a second sense; and summing means connected to the resistance network and the operational rectifier for summing the signals therefrom and for providing a signal of the second sense having an amplitude corresponding to the amplitude of the signal.
Claim 14
Dependent Claim
64 words
A circuit of the type described in claim 1, adapted for comparing two signals of opposite sense, in which the absolute value amplifier includes summing means for receiving the two signals and for providing a signal corresponding to the difference between the absolute amplitudes of the signals, the absolute value amplifier being responsive thereto for providing the unipolar signal corresponding to the difference signal.
Claim 15
Dependent Claim
33 words
A circuit as described in claim 13, in which the signals are of the same sense and the absolute value amplifier additionally includes an inverter for receiving and inverting one of the signals.
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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |