US3559009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
D.c. motor control system which compares the motor current with a reference to control the motor speed
Assignee: Westinghouse Electric Corp
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Filing: 1968-03-06
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Granted: 1971-01-26
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Expires: 1988-03-06
Abstract
Abstract A CONTROL SYSTEM FOR TRACTION MOTORS FOR RAPID TRANSIT CARS. THE SYSTEM INCLUDES A DIRECT CURRENT CHOPPER UTILIZING THYRISTORS FOR CONNECTING THE MOTORS TO THE POWER SOURCE AND MEANS FOR TURNING THE CHOPPER ON AND OFF AS REQUIRED TO MAINTAIN A DESIRED AVERAGE MOTOR CURRENT. PULSE GENERATORS PROVIDE THE GATE PULSES FOR THE THYRISTORS TO TURN THE CHOPPER ON AND OFF AND THE PULSE GENERATORS ARE ACTUATED BY A CONTROL CIRCUIT WHICH COMPARES THE MOTOR CURRENT WITH A SIGNAL REPRESENTING THE DESIRED MOTOR CURRENT. THE CONTROL CIRCUIT ALSO INCLUDES MEANS FOR MAINTAINING A PREDETERMINED RIPPLE IN THE MOTOR CURRENT.
Inventors
- 👤 John M Mills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 02:26
CPC Classifications
B; B60; B60L; B60L9/00; B60L9/02; B60L9/04; H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; B60L2200/00; B60L2200/26; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/72
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |