US3727133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection of commutation defects
Assignee: General Electric Co
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Filing: 1970-12-28
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Granted: 1973-04-10
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Expires: 1990-12-28
Abstract
Abstract A signal is derived corresponding to variations in the unidirectional current flowing in the external power lines to a direct current rotating machine. A second signal is derived from the first signal having a period equal to the period of revolution of a commutator divided by the number of commutator segments. The appearance in the second signal of peaks short in duration in relation to said period indicates a defect in commutation of current in the armature winding of the direct current machine.
Inventors
- 👤 B Weichbrodt
- 👤 J Marvin
- 👤 F Martzloff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:14
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34; G01R31/343
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
200 words
APparatus for detecting commutation defects in a direct current rotating machine having a commutator and a pair of power conductors coupled therewith for conducting unidirectional currents with a low frequency component having a period determined by a single revolution of the commutator divided by the number of commutator segments comprising sensor means for deriving a first signal corresponding to variations in said unidirectional current and including a high frequency component indicative of a commutation defect, circuit means for deriving from said first signal a second signal having said low frequency component period in which said high frequency component is enhanced, and detection means for detecting a peak in said second signal of a duration short in relation to said low frequency component period to provide an indication of a commutation defect, said detection means including means for deriving a mean value signal corresponding to the average value of a rectification of said second signal, means for deriving a peak value signal corresponding to the peak value of said second signal, and means for deriving an output signal corresponding to the ratio of the amplitudes of said peak value and mean value signals said output signal being indicative of commutation defects.
Claim 2
Dependent Claim
200 words
APparatus for detecting commutation defects in a direct current rotating machine having a commutator and a pair of power conductors coupled therewith for conducting unidirectional currents with a low frequency component having a period determined by a single revolution of the commutator divided by the number of commutator segments comprising sensor means for deriving a first signal corresponding to variations in said unidirectional current and including a high frequency component indicative of a commutation defect, circuit means for deriving from said first signal a second signal having said low frequency component period in which said high frequency component is enhanced, and detection means for detecting a peak in said second signal of a duration short in relation to said low frequency component period to provide an indication of a commutation defect, said detection means including means for deriving a mean value signal corresponding to the average value of a rectification of said second signal, means for deriving a peak value signal corresponding to the peak value of said second signal, and means for deriving an output signal corresponding to the ratio of the amplitudes of said peak value and mean value signals said output signal being indicative of commutation defects.
Claim 3
Dependent Claim
205 words
Apparatus for detecting commutation defects in a direct current rotating machine having a commutator and associated brushes, and a pair of external power conductors effectively connected to said brushes and conducting unidirectional currents with a low frequency component having a period determined by a single revolution of the commutator divided by the number of commutator segments comprising sensor means for removable coupling to one of said external power conductors for deriving a first signal corresponding to variations in said unidirectional current and including a high frequency component indicative of a commutation defect, circuit means including a high pass filter for deriving from said first signal a second signal having said low frequency component in which said high frequency component is enhanced, and detection means for detecting a peak in said second signal of a duration short in relation to said low frequency component period to provide an indication of a commutation defect, said detection means comprising a peak detector circuit, a mean value circuit for deriving a means value of said second signal, and a circuit for deriving an output signal corresponding to the ratio of the outputs of said peak detector and mean value circuits which output signal is an indication of commutation defects.
Claim 4
Dependent Claim
205 words
Apparatus for detecting commutation defects in a direct current rotating machine having a commutator and associated brushes, and a pair of external power conductors effectively connected to said brushes and conducting unidirectional currents with a low frequency component having a period determined by a single revolution of the commutator divided by the number of commutator segments comprising sensor means for removable coupling to one of said external power conductors for deriving a first signal corresponding to variations in said unidirectional current and including a high frequency component indicative of a commutation defect, circuit means including a high pass filter for deriving from said first signal a second signal having said low frequency component in which said high frequency component is enhanced, and detection means for detecting a peak in said second signal of a duration short in relation to said low frequency component period to provide an indication of a commutation defect, said detection means comprising a peak detector circuit, a mean value circuit for deriving a means value of said second signal, and a circuit for deriving an output signal corresponding to the ratio of the outputs of said peak detector and mean value circuits which output signal is an indication of commutation defects.
Claim 5
Dependent Claim
32 words
Apparatus according to claim 2 further including a long time constant circuit for averaging said output signal to thereby reject extraneous peaks in said second signal not indicative of a commutation defect.
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) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |