Patent US3673422A successfully refreshed from Google Patents.
US3673422A
Expired / Lapsed
US
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Loss of synchronism detector
Assignee: MARINE ELECTRIC RAILWAY PRODUCTS DIVISION Inc A NEW YORK CORP
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Filing: 1971-01-18
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Granted: 1972-06-27
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Expires: 1991-01-18
Abstract
Abstract A driving machine and a driven machine are to be kept in synchronism. Tachometer generators attached to both machines generate signals which charge a capacitor either positively or negatively with respect to a given reference, and should the charge on this capacitor increase above a certain level, a circuit breaker means opens the line connecting the armatures of the two machines.
Inventors
- 👤 Harry G Parke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:33
CPC Classifications
H; H02; H02P; H02P5/00; H02P5/46; H02P5/50; H02H; H02H3/00; H02H3/48; H02H7/00; H02H7/08; H02H7/0805
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
94 words
A system for detecting loss of synchronism between two machines comprising a driving machine; first means to generate a signal proportional to the speed of the driving machine; a driven machine; second means to generate a signal proportional to the speed of the driven machine opposite in polarity, to that of said first means; charging means connected to the first and second means; means for measuring increases in net potential across the charging means; and means to disconnect the machines in response to the measuring means detecting a predetermined increase in said net potential.
Claim 2
Independent Claim
94 words
A system for detecting loss of synchronism between two machines comprising a driving machine; first means to generate a signal proportional to the speed of the driving machine; a driven machine; second means to generate a signal proportional to the speed of the driven machine opposite in polarity, to that of said first means; charging means connected to the first and second means; means for measuring increases in net potential across the charging means; and means to disconnect the machines in response to the measuring means detecting a predetermined increase in said net potential.
Claim 3
Dependent Claim
13 words
The system of claim 1 wherein the first and second means are tachometers.
Claim 4
Dependent Claim
33 words
The system of claim 2 wherein the output of one tachometer charges the charging means to one polarity and the output of the other tachometer charges the charging means to the opposite polarity.
Claim 5
Dependent Claim
39 words
The system of claim 3 wherein the measuring means comprises means for comparing the potential of one polarity of the charging means with one standard, and another means for comparing the potential of the opposite polarity with another standard.
Claim 6
Dependent Claim
36 words
The system of claim 4 further comprising first and second capacitors; and first and second switches activated by the respective tachometers, said switches charging the respective capacitors and then discharging them into the respective charging means.
Claim 7
Dependent Claim
12 words
The system of claim 5 wherein the switches are electron conductive devices.
Claim 8
Independent Claim
123 words
A system for detecting loss of synchronism between two electrically coupled machines comprising a frequency producing means associated with each machine; a first charging means; a second charging means associated with one machine; a third charging means associated with the other machine; a first switch to energize the second charging means according to one polarity and then discharge it into the first charging means at the frequency of said frequency producing means for said one machine; a second switch to energize the third charging means according to the opposite polarity and then discharge it into the first charging means at the frequency of said frequency producing means for said other machine; and means to analyze the net potential across the first charging means.
Claim 9
Independent Claim
123 words
A system for detecting loss of synchronism between two electrically coupled machines comprising a frequency producing means associated with each machine; a first charging means; a second charging means associated with one machine; a third charging means associated with the other machine; a first switch to energize the second charging means according to one polarity and then discharge it into the first charging means at the frequency of said frequency producing means for said one machine; a second switch to energize the third charging means according to the opposite polarity and then discharge it into the first charging means at the frequency of said frequency producing means for said other machine; and means to analyze the net potential across the first charging means.
Claim 10
Dependent Claim
15 words
The device of claim 7 wherein the first and second switches are electron conductive devices.
Claim 11
Dependent Claim
34 words
The system of claim 8 wherein the analyzing means comprises a first comparator for comparint the net potential with one standard; and a second comparator for comparing the net potential with an opposite standard.
Claim 12
Dependent Claim
37 words
The system of claim 9 further including actuator means connected to the output of the respective comparators to sever electrically the connection between the coupled machines if there is a predetermined potential on the first charging means.
Claim 13
Independent Claim
237 words
A system for detecting loss of synchronism between two electrically coupled electro-magnetic machines comprising in combination: a driving electro-magnetic machine; a driven electro-magnetic machine; a first AC tachometer generator driven by said driving machine; a second AC tachometer generator driven by said driving machine; capacitor means; first charging means connected to said first tachometer generator, to a source of potential of a given polarity, and to said capacitor means, said charging means being adapted for providing said capacitor means with a train of charging pulses of said first poLarity at a rate proportional to the speed of said first tachometer generator; second charging means connected to said second tachometer generator, to a source of potential of a polarity opposite to said given polarity, and to said capacitor means, said second means being adapted for providing said capacitor means with a train of charging pulses of said opposite polarity at a rate proportional to the speed of said second tachometer generator whereby the polarity and quantity of charge on said capacitor is a function of the difference of speed of the first and second tachometer generators and of said driving and driven machines; means for comparing said capacitor charge to preselected reference levels and providing an output signal upon a predetermined difference being attained; and actuator means connected to receive said output signal and electrically disrupt the connection between said coupled electro-magnetic machines upon receipt of said signal.
Claim 14
Independent Claim
237 words
A system for detecting loss of synchronism between two electrically coupled electro-magnetic machines comprising in combination: a driving electro-magnetic machine; a driven electro-magnetic machine; a first AC tachometer generator driven by said driving machine; a second AC tachometer generator driven by said driving machine; capacitor means; first charging means connected to said first tachometer generator, to a source of potential of a given polarity, and to said capacitor means, said charging means being adapted for providing said capacitor means with a train of charging pulses of said first poLarity at a rate proportional to the speed of said first tachometer generator; second charging means connected to said second tachometer generator, to a source of potential of a polarity opposite to said given polarity, and to said capacitor means, said second means being adapted for providing said capacitor means with a train of charging pulses of said opposite polarity at a rate proportional to the speed of said second tachometer generator whereby the polarity and quantity of charge on said capacitor is a function of the difference of speed of the first and second tachometer generators and of said driving and driven machines; means for comparing said capacitor charge to preselected reference levels and providing an output signal upon a predetermined difference being attained; and actuator means connected to receive said output signal and electrically disrupt the connection between said coupled electro-magnetic machines upon receipt of said signal.
Claim 15
Dependent Claim
64 words
A system in accordance with claim 11 wherein each of said charging means comprises a capacitor, a source of potential of the polarity associated with said means, and a switching means adapted for connecting said capacitor alternately between said source of potential and said capacitor means at a switching rate proportional to the output frequency of the tachometer generator connected to said charging means.
Claim 16
Dependent Claim
57 words
A system according to claim 12 wherein said switching means comprises a pair of field effect transistors respectively connecting said capacitor to said source of potential and to said capacitor means, the gates of said first and second transistors being connected for alternate activation in accordance with the frequency of the output from said associated tachometer generator.
References Cited (Backward Citations)
US3024395A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |