US4380724A
Expired / Lapsed
US
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Shunt field control apparatus and method
Assignee: Bombardier Transportation Holdings USA Inc
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Filing: 1980-11-24
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Granted: 1983-04-19
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Expires: 2000-11-24
Abstract
Abstract A motor control is provided for a DC series motor operative with a chopper apparatus and including a thyristor switch to determine the field shunt operation of the motor. A voltage reversal that occurs across the field windings when the chopper is OFF and not conducting is utilized to commutate and enable modulation of the field shunt thyristor switch as desired in relation to the chopper ON and OFF operation.
Inventors
- 👤 James H. Franz, Jr.
- 👤 Stanley W. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:27
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/298; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/72; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/915; Y10S388/917; Y10S388/92
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
143 words
In shunt field control apparatus for a motor operative with a voltage supply and having a shunt field and a series connected armature and main field, the combination of chopper means coupled between the voltage supply and the series connected armature and main field, said chopper means having successive ON and OFF operations to determine the average voltage across the series connected armature and main field and providing a predetermined polarity voltage across the main field during each of said OFF operations, switch means coupled with the shunt field and conductive for connecting the shunt field across the main field, and means connected across the shunt field for providing a current path around the shunt field in relation to voltage across the shunt field and providing said predetermined polarity voltage across the switch means to turn OFF the conduction of the switch means.
Claim 2
Dependent Claim
143 words
In shunt field control apparatus for a motor operative with a voltage supply and having a shunt field and a series connected armature and main field, the combination of chopper means coupled between the voltage supply and the series connected armature and main field, said chopper means having successive ON and OFF operations to determine the average voltage across the series connected armature and main field and providing a predetermined polarity voltage across the main field during each of said OFF operations, switch means coupled with the shunt field and conductive for connecting the shunt field across the main field, and means connected across the shunt field for providing a current path around the shunt field in relation to voltage across the shunt field and providing said predetermined polarity voltage across the switch means to turn OFF the conduction of the switch means.
Claim 3
Dependent Claim
29 words
The control apparatus of claim 1, with the means connected across the shunt field providing a conduction path for any voltage across the shunt field having said predetermined polarity.
Claim 4
Dependent Claim
17 words
The control apparatus of claim 1, with the means connected across the shunt field comprising a diode.
Claim 5
Dependent Claim
132 words
In a method of control for a motor connected with a motor reactor and having an armature, a main field and a shunt field, the steps of providing a first voltage across said motor reactor, said armature and said main field for successive ON and OFF operational time periods to determine the average energization of that armature and main field, providing a predetermined polarity second voltage across the main field during said OFF time periods, connecting the shunt field across the main field when a shunt field operation of the motor is desired, and applying said predetermined polarity second voltage to disconnect the shunt field from across the main field during said OFF time periods when the current of the motor reactor has fallen to substantially the current of the motor fields.
Claim 6
Dependent Claim
132 words
In a method of control for a motor connected with a motor reactor and having an armature, a main field and a shunt field, the steps of providing a first voltage across said motor reactor, said armature and said main field for successive ON and OFF operational time periods to determine the average energization of that armature and main field, providing a predetermined polarity second voltage across the main field during said OFF time periods, connecting the shunt field across the main field when a shunt field operation of the motor is desired, and applying said predetermined polarity second voltage to disconnect the shunt field from across the main field during said OFF time periods when the current of the motor reactor has fallen to substantially the current of the motor fields.
Claim 7
Dependent Claim
30 words
The method of claim 4, including the step of providing a conductive path around the shunt field in relation to any voltage across the shunt field having said predetermined polarity.
References Cited (Backward Citations)
US3360705A
Cited
US3562616A
Cited
US3906317A
Cited
US3983465A
Cited
US3947738A
Cited
US4019108A
Cited
US4282466A
Cited
US4284930A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-18 | 1986-10-18 | 1987-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-18 | 1990-10-18 | 1991-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-18 | 1994-10-18 | 1995-04-19 | $7700.00 | Window Closed / Lapsed |