US3652933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for producing a signal when a selected phase relationship exists between two alternating current voltages of different frequencies
Assignee: Westinghouse Electric Corp
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Filing: 1969-12-23
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Granted: 1972-03-28
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Expires: 1989-12-23
Abstract
Abstract A signal is produced when a selected phase relationship exists between two alternating current voltages of different frequencies by converting the alternating current waveforms to square waves, combining the square waves to produce a rectangular waveform, and utilizing the rectangular waveform to produce a triangular beat frequency signal having a linear relationship between phase difference and time, and a level detector has the triangular beat frequency signal applied thereto and produces an output signal when the triangular beat frequency signal exceeds in amplitude a selected level in the level detector.
Inventors
- 👤 Tibor Rubner
- 👤 Andre Wavre
- 👤 John H Bednarek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:50
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/26; H02; H02J; H02J3/00; H02J3/38; H02J3/40; H02J3/42
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
247 words
In apparatus for obtaining a signal at a selected phase relationship between two alternating current voltages of different frequencies, in combination, circuit means adapted to have first and second alternating current voltages of different frequencies applied thereto, said circuit means producing first and second square waves having frequencies corresponding to those of the first and second alternating current voltages respectively, other circuit means having the first and second square waves applied thereto and producing an output rectangular waveform obtained by combining the first and second square waves, further circuit means having the output rectangular waveform applied thereto and producing a triangular beat frequency signal having a linear relationship between phase difference and time, a level detector having the triangular beat frequency signal applied thereto, said level detector producing said first-named signal when the triangular beat frequency signal exceeds in amplitude a selected adjustable level in the level detector, summing circuit means having the triangular beat frequency signal having a linear relationship between phase difference and time applied thereto, differentiator means having the triangular beat frequency signal applied thereto, means for applying the output of the differentiator means to the summing circuit means to obtain a further waveform representing the algebraic sum of the triangular beat frequency signal and its first derivative, and a further level detector having the further waveform applied thereto as an input, said further level detector producing an output while the input thereto is above a selected, adjustable level in the further level detector.
Claim 2
Dependent Claim
247 words
In apparatus for obtaining a signal at a selected phase relationship between two alternating current voltages of different frequencies, in combination, circuit means adapted to have first and second alternating current voltages of different frequencies applied thereto, said circuit means producing first and second square waves having frequencies corresponding to those of the first and second alternating current voltages respectively, other circuit means having the first and second square waves applied thereto and producing an output rectangular waveform obtained by combining the first and second square waves, further circuit means having the output rectangular waveform applied thereto and producing a triangular beat frequency signal having a linear relationship between phase difference and time, a level detector having the triangular beat frequency signal applied thereto, said level detector producing said first-named signal when the triangular beat frequency signal exceeds in amplitude a selected adjustable level in the level detector, summing circuit means having the triangular beat frequency signal having a linear relationship between phase difference and time applied thereto, differentiator means having the triangular beat frequency signal applied thereto, means for applying the output of the differentiator means to the summing circuit means to obtain a further waveform representing the algebraic sum of the triangular beat frequency signal and its first derivative, and a further level detector having the further waveform applied thereto as an input, said further level detector producing an output while the input thereto is above a selected, adjustable level in the further level detector.
Claim 3
Dependent Claim
86 words
Apparatus according to claim 1 in which the instant when the output of the first-named level detector starts represents a definite phase relationship between the first and second alternating current voltages, and the output of the further level detector occurs at a definite time before phase coincidence of the bus and generator voltages independent of the frequency difference between them, and including in addition logic circuitry having the output of the first-named level detector and the output of the further level detector applied thereto as inputs.
Claim 4
Dependent Claim
162 words
Apparatus according to claim 2 in which the logic circuitry inCludes a first AND circuit and a first NOT circuit both having the output of the first named level detector applied thereto, a second AND circuit and a second NOT circuit both having the output of the further level detector applied thereto, means applying the output of the second NOT circuit as an input to the first AND circuit, a bistable circuit operatively connected to the first AND circuit to be set by an output of the first AND circuit, said bistable circuit being operatively connected to the first NOT circuit to be reset by an output of the first NOT circuit, and means connecting the second AND circuit to the bistable circuit to receive an input from the bistable circuit while the bistable circuit is in set condition, said second AND circuit when all inputs are simultaneously present thereat producing an output adapted to be utilized to close a circuit breaker.
Claim 5
Dependent Claim
48 words
Apparatus according to claim 3 in which the second AND circuit has an additional third input, and including in addition a further bistable circuit operatively connected to the second AND circuit to supply a third input thereto while the further bistable circuit is in a selected stable state.
Claim 6
Dependent Claim
58 words
Apparatus according to claim 4 in which the further bistable circuit has first and second input means adapted to receive signals to cause the further bistable circuit to assume ''''set'''' and ''''reset'''' stable states, and timer means connected between the first and second input means, said timer means resetting the logic circuitry after a predetermined interval of time.
Claim 7
Dependent Claim
212 words
In apparatus for obtaining a signal at a selected phase relationship between two alternating current voltages of different frequencies, in combination, circuit means adapted to have first and second alternating current voltages of different frequencies applied thereto, said circuit means producing first and second square waves having frequencies corresponding to those of the first and second alternating current voltages respectively, other circuit means having the first and second square waves applied thereto and producing an output rectangular waveform obtained by combining the first and second square waves, further circuit means having the output rectangular waveform applied thereto and producing a triangular beat frequency signal having a linear relationship between phase difference and time, a level detector having the triangular beat frequency signal applied thereto, said level detector producing said first-named signal when the triangular beat frequency signal exceeds in amplitude a selected adjustable level in the level detector, an additional circuit means for obtaining a different function of said triangular beat frequency signal, a summing circuit for obtaining an output which is the algebraic sum of said amplitude and said different function of said triangular beat frequency signal, and an additional level detector which is responsive to said algebraic sum for producing an output when said algebraic sum exceeds a selected level.
Claim 8
Dependent Claim
212 words
In apparatus for obtaining a signal at a selected phase relationship between two alternating current voltages of different frequencies, in combination, circuit means adapted to have first and second alternating current voltages of different frequencies applied thereto, said circuit means producing first and second square waves having frequencies corresponding to those of the first and second alternating current voltages respectively, other circuit means having the first and second square waves applied thereto and producing an output rectangular waveform obtained by combining the first and second square waves, further circuit means having the output rectangular waveform applied thereto and producing a triangular beat frequency signal having a linear relationship between phase difference and time, a level detector having the triangular beat frequency signal applied thereto, said level detector producing said first-named signal when the triangular beat frequency signal exceeds in amplitude a selected adjustable level in the level detector, an additional circuit means for obtaining a different function of said triangular beat frequency signal, a summing circuit for obtaining an output which is the algebraic sum of said amplitude and said different function of said triangular beat frequency signal, and an additional level detector which is responsive to said algebraic sum for producing an output when said algebraic sum exceeds a selected level.
References Cited (Backward Citations)
US3441862A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |