Patent US3293518A successfully refreshed from Google Patents.
US3293518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronous motor starting circuit
Assignee: Allis Chalmers Corp
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Filing: 1964-07-16
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Granted: 1966-12-20
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Expires: 1984-07-16
Abstract
No abstract record available.
Inventors
- 👤 Manfred E Neumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:58
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/16; H02P1/46
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
224 words
A CIRCUIT FOR CONNECTING A SYNCHRONOUS MOTOR FIELD WINDING TO ITS EXCITER FOR SYNCHRONOUS OPERATION AND TO BE SHORT CIRCUITED AND ISOLATED FROM ITS EXCITER FOR SUBSYNCHRONOUS ACCELERATION, COMPRISING: FIRST SEMICONDUCTOR SWITCH DEVICE HAVING A PAIR OF LOAD TERMINALS CONNECTED TO SHORT CIRCUIT THE FIELD WINDING IN AT LEAST ONE DIRECTION OF INDUCED FIELD CURRENT WHEN SAID FIRST DEVICE IS TURNED ON, SAID DEVICE BEING OF THE TYPE TO STOP CONDUCTION IN SAID ONE DIRECTION WHEN AN OPPOSITE POLARITY VOLTAGE IS APPLIED ACROSS ITS LOAD TERMINALS, SAID LOAD TERMINALS BEING CONNECTABLE TO THE EXCITER TERMINALS FOR SYNCHRONOUS OPERATION, A CAPACITOR HAVING ONE OF ITS TERMINALS CONNECTED TO ONE TERMINAL OF SAID FIRST SEMICONDUCTOR DEVICE, A SECOND SEMICONDUCTOR DEVICE CONNECTING SAID CAPACITOR ACROSS THE TERMINALS OF THE FIELD WINDING TO BE CHARGED ON HALF CYCLES OF INDUCED FIELD CURRENT OPPOSITE TO SAID ONE DIRECTION OF INDUCED CURRENT, A THIRD SEMICONDUCTOR DEVICE RESPONSIVE TO A CONTROL SIGNAL TO TURN ON AND CONDUCT BETWEEN A PAIR OF LOAD TERMINALS, ONE OF ITS LOAD TERMINALS BEING CONNECTED TO THE OTHER TERMINAL OF SAID CAPACITOR, THE OTHER OF ITS LOAD TERMINALS BEING CONNECTED TO THE OTHER TERMINAL OF SAID FIRST SEMICONDUCTOR DEVICE TO APPLY THE VOLTAGE OF THE CAPACITOR TO SAID FIRST DEVICE IN A POLARITY OF TURN OFF SAID FIRST DEVICE WHEN SAID THIRD DEVICE IS TURNED ON.
Claim 2
Dependent Claim
224 words
A CIRCUIT FOR CONNECTING A SYNCHRONOUS MOTOR FIELD WINDING TO ITS EXCITER FOR SYNCHRONOUS OPERATION AND TO BE SHORT CIRCUITED AND ISOLATED FROM ITS EXCITER FOR SUBSYNCHRONOUS ACCELERATION, COMPRISING: FIRST SEMICONDUCTOR SWITCH DEVICE HAVING A PAIR OF LOAD TERMINALS CONNECTED TO SHORT CIRCUIT THE FIELD WINDING IN AT LEAST ONE DIRECTION OF INDUCED FIELD CURRENT WHEN SAID FIRST DEVICE IS TURNED ON, SAID DEVICE BEING OF THE TYPE TO STOP CONDUCTION IN SAID ONE DIRECTION WHEN AN OPPOSITE POLARITY VOLTAGE IS APPLIED ACROSS ITS LOAD TERMINALS, SAID LOAD TERMINALS BEING CONNECTABLE TO THE EXCITER TERMINALS FOR SYNCHRONOUS OPERATION, A CAPACITOR HAVING ONE OF ITS TERMINALS CONNECTED TO ONE TERMINAL OF SAID FIRST SEMICONDUCTOR DEVICE, A SECOND SEMICONDUCTOR DEVICE CONNECTING SAID CAPACITOR ACROSS THE TERMINALS OF THE FIELD WINDING TO BE CHARGED ON HALF CYCLES OF INDUCED FIELD CURRENT OPPOSITE TO SAID ONE DIRECTION OF INDUCED CURRENT, A THIRD SEMICONDUCTOR DEVICE RESPONSIVE TO A CONTROL SIGNAL TO TURN ON AND CONDUCT BETWEEN A PAIR OF LOAD TERMINALS, ONE OF ITS LOAD TERMINALS BEING CONNECTED TO THE OTHER TERMINAL OF SAID CAPACITOR, THE OTHER OF ITS LOAD TERMINALS BEING CONNECTED TO THE OTHER TERMINAL OF SAID FIRST SEMICONDUCTOR DEVICE TO APPLY THE VOLTAGE OF THE CAPACITOR TO SAID FIRST DEVICE IN A POLARITY OF TURN OFF SAID FIRST DEVICE WHEN SAID THIRD DEVICE IS TURNED ON.
References Cited (Backward Citations)
US3098959A
Cited
US3100279A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-12-19 | 1970-06-20 | 1970-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-19 | 1974-06-20 | 1974-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-19 | 1978-06-20 | 1978-12-20 | $7700.00 | Window Closed / Lapsed |